2018 Abstracts

Oral communications, invited talks and posters presented at the WPSA UK Branch Meeting held at the Croke Park, Dublin (10–11 April 2018). These summaries have been edited for clarity and style by the WPSA UK Programme Committee but have not been fully peer-reviewed.

Breeding for prolonged laying cycles in laying hens, a breeding programme explained.

T. van de Braak

The impacts of UK buyers’ intentions to purchase only non-cage eggs from 2025.

J. Gittins

Growth and egg laying performance of Japanese quails fed diets containing varying levels of sorghum and maize.

A. T. Ijaiya, S. S. A. Egena, O. Omamugho and S. Adio

Evaluation of oats with varying husk inclusion on performance, energy and nitrogen retention in broilers.

D. V. Scholey, A. Marshall, S. Cowan and E. J. Burton

Egg quality is improved when a 300ppm calcium pidolate supplement is added to the layer diet from 50 to 70 wks.

M. M. Bai, T. Parkin, R. Gill, D. Brass and b. Pollet

Favourable genetic parameters for the improvement of cuticle deposition on eggs.

I. C. Dunn, P. W. Wilson, M. M. Bain, A. Jones, F. Quinlan-pluck, G. O. S. Williams, W. Icken and V. Olori

The effect of ranking laying hens by feed efficiency on the quality and nutrient composition of eggs.

Y. Akter, S. Greenhalgh, M. D. Islam, D. Anene and C. J. O’Shea

Quantitative assessment for the risk of recrudescence of avian influenza in caged layer houses following depopulation: the effect of cleansing, disinfection and dismantling of complex equipment.

P. Gale, S. Sechi, V. Horigan and L. Kelly

Growth performance and behaviour of broiler chicken reared under two different light bulb sources and distances.

O. O. Adeleye, L. T. Egbeyale, O. Ayo-ajasa, M. O. Abatan, A. W. Abdkareem, A. O. Odukoya and o. E. Akinsola

Superoxide dismutase activity in the chicken gut.

P. F. Surai, I. I. Kochish and S. O. Shapovalov.

Investigation into the effect of semi-synthetic diets on the intestinal mucin layer of broilers.

S. Amir, D. V. Scholey, M. Le Bon, E. J. Burton and C. Turkura

Dietary prebiotic, probiotic and synbiotic supplementation on the immune function of meat chickens.

A. Alsudani, S. Ali, M. Le Bon, D. V. Scholey, G. Manning and E. J. Burton

Influence of naked neck gene and housing system on egg production and immune response of laying hens.

M. Fathi, I. Al-Homidan, T. Ebeid and O. Abou-Emera

Supporting gut health of high performing boilers in the presence of coccidiosis.

D. Harrington, H. Hall, G. Mathis and W. Wakeman

Curcuma longa supplementation in broiler feed: effect on physiological responses and performance under a hot, humid, tropical climate.

O. Oke, J. Daramola, A. Rahman and T. Lawal

The effect of calcareous marine algae in diets containing low levels of calcium on broiler performance, bone strength and meat quality parameters.

M. E. E. Ball, D. Farrell and S. Taylor

A bird’s eye view of lighting in poultry housing – the science of poultry vision.

D. L. Williams

Going ‘cage free’ by 2025 – welfare consequences for laying hens.

V. Sandilands

Growing site influences wheat apparent metabolisable energy value for broiler chickens.

R. Azhar, S. P. Rose, S. C. Mansbridge, M. R. Bedford and V. R. Pirgozliev

A method to increase the energy and nitrogen availability of rapeseed supplemented diets for broilers.

E. Watts, V. R. Pirgozliev, S. P. Rose, A. Mackenzie and L. Bernard

Evaluating the effects of low crude protein diets on growth performance, meat quality, litter moisture, nitrogen excretion and environmental impacts in finishing broilers.

B. Méda, P. Belloir, W. Lambert, E. Corrent, H. Juin, S. Tesseraud and M. Lessire

Xylanase effect on growth partly explained by effect on pre-caecal flow of carbohydrate fractions in broilers.

A. Craig, M. Bedford, P. Hastie, F. Khattak and O. Olukosi

Analysis of insulin-like growth factor 1 gene in Nigerian indigenous and Arbor Acre chickens.

M. Wheto, O. O. Ismaila, A. S. Adenaike, M. A. Adeleke, S. O. Peters, C. O. N. Ikeobi and O. A. Adebambo

Effects of diets supplemented with different zinc sources on performance, egg quality, parameters of bones and zinc retention in laying hens.

F. Shariatmadari, M. Abedini, H. Ahmadi and M. A. K. Torshizi

Effects of diets supplemented with different zinc sources on performance, egg quality, parameters of bones and zinc retention in laying hens at late phase of production

F. Shariatmadari, M. Abedini and H. Ahmadi

Investigations into the efficacy of novel antimicrobial peptides against Histomonas meleagridis, the causative agent of blackhead disease in poultry.

J. Pickup

The influence of Fenugreek (Trigonella foenum-graecum L.) Garden cress (Lepidium sativum) supplementation on growth performance and cell-mediated immunity of broilers.

I. Al-Homidan, T. Ebeid, A. Al-Muzaini, O. Abou-Emera and M. Fathi

Amino acid digestibility varies between different wheat varieties for broiler chickens.

R. Azhar, S. P. Rose, M. R. Bedford and V. R. Pirgozliev

Gizzard pH in broiler chicks in the immediate post placement period.

N. Morgan, P. Garland, D. V. Scholey and E. J. Burton

Reducing the impact of enteritis on bird performance using oregano essential oil.

D. Harrington, H. Hall, S. Srinongkote and W. Wakeman

An examination of bio-available and total silicon in broiler chickens through evaluation of the solid and aqueous phases of digesta.

H. Hayton, S. Prentice, D. V. Scholey and E. J. Burton

The effect of silica supplementation on bone parameters in broiler chickens.

M. Bradley, S. Prentice, D. V. Scholey and E. J. Burton

The effect of feeding different selenium sources on the antioxidant status of broiler chickens.

S. Woods, I. M. Whiting, S. P. Rose, D. Bravo, S. Sobolewska and V. R. Pirgozliev.

Breeding for prolonged laying cycles in laying hens, a breeding programme explained

T. van de Braak

Hendrix-Genetics, Boxmeer, The Netherlands

CONTACT T. van de Braak [email protected]

The changing market is changing the breeding programmes of laying hens, as on the other hand the continuous improvement in the laying persistency and the egg quality of laying hens is also influencing the market.

It has been 10 years since Hendrix Genetics expanded the length of their breeding programme for laying hens from 80 weeks until 100 weeks of age. The breeding programme was expanded as genetic variation for several traits had been reduced because of decades of selective breeding, and on the other hand also due to the need from the egg-market to become more sustainable. This expansion allowed the breeding company to measure more variation between selection candidates and their families. This genetic variation allowed to make significant improvement of the production performance of laying hens, as this genetic progress is passed on from generation to generation. The genetic improvement also resulted in a lower environmental impact from laying hens. Dunn (2013) highlighted in a UK example that when you prolonged the laying cycle by 10 weeks, 1 g of Nitrogen could be saved for every dozen eggs produced. But it is not only egg numbers and the birds’ efficiency that drive a breeding programme. The most important traits, but on the same hand also the most complex traits, to genetically improve are the robustness and behavioural traits. One could think about liveability, cannibalistic pecking behaviour and feather cover as traits that play an important role in today’s breeding programme. The challenges for making genetic improvements in these aforementioned traits can be the biological complexity of the trait, the difficulty to record accurate phenotypes on the birds and low heritability.

On the other hand, the farm environment is also changing drastically in developed countries. The European ban on conventional cages and the increased worldwide pressure from retailers, society and NGO’s on the intensification of egg production have led to incredibly fast changes in the way that birds are kept in the current situation. Breeding birds that perform well in alternative systems require a different approach compared to breeding for conventional cages. For example, the move towards alternative systems also has a big impact in the way that breeding companies collect their data. Collecting individual and family data is key for any breeding programme, irrespective of the species, that you apply your breeding programme to. With the move towards alternative housing systems, you need to breed for birds that are able to perform well in large groups, and to breed for birds that efficiently make use of the housing systems that they are in. 10 years ago, the aforementioned would be a breeder’s worst nightmare. But by combined researches with Universities and laying house equipment manufacturers we are developing a system in which we can accurately collect individual egg recordings from birds housed in larger groups.

Overall we can conclude that the entire poultry industry has made drastic improvements in the way that we keep our hens today and to exploit the genetic potential of the hens of today, particularly with regards to sustainability and welfare considerations.

Reference

• Dunn, I. C. (2013). 19th European Symposium on Poultry Nutrition (124–129). Potsdam.
   Google Scholar

The impacts of UK buyers’ intentions to purchase only non-cage eggs from 2025

J. Gittins

ADAS, Aberystwyth, UK

CONTACT J. Gittins [email protected]

A number of multiple retailers in the UK have announced that they will stop selling eggs from enriched cage systems from the start of 2025. At this stage, the extent to which there will be growth in barn egg production and the likely impact on the free range sector is unclear.

The overall aim of this study, commissioned by the British Free Range Egg Producers Association, was to provide clarity on retailers’ current thinking and to assess the likely implications of changing purchase policies. Meetings were held with various retailer representatives between March and May 2017. Participants were assured that their individual responses would be used for aggregation purposes only.

The retailers that have recently made a commitment to non-cage eggs from 2025 represent around 67% of the overall UK grocery market at present. It has been assumed that this same percentage reflects their overall share of retail sales of eggs. On the basis of the responses provided, enriched cage eggs are currently estimated to account for a weighted average of 35% of sales by these retailers. Free range (including organic) represents the remaining 65% since at present, barn egg production is insignificant.

Most of these retailers forecast some growth in the market share of free range due to changing buying habits up to 2025. However, there were some differences of opinion on this point and an acknowledgement that future buying habits could be affected by a range of factors, including changes in the general economic situation of the country.

Retailers stated their intentions to offer barn eggs in future for their ‘value’ lines although not all had completely dismissed the idea of a move to free range only in 2025. There was agreement that customers who are still buying enriched cage eggs as 2025 approaches would switch to barn eggs if these become the cheapest option. Questions were raised over consumer understanding of barn production, the housing systems that would be acceptable and its longer-term prospects.

Although retailers’ commitment to non-cage specifically relates to own-brand eggs, it is considered unlikely that any tertiary or packer-branded eggs from enriched cages would be offered after 2025. A possible exception to this is short-term supply to help manage the changes needed at the end of 2024. All retailers currently rule out a switch to non-cage for all of their egg products. This is mainly because of the number of different products and suppliers and since egg may be only a very minor ingredient in some foods.

Following retailer discussions, a series of assessments was made of the likely impacts of changes in retailer purchasing policies and consumer preferences between 2017 and 2025. These have assumed an overall increase in the UK human population by 2025 but no changes to egg consumption per person, nor to the percentage of eggs sold by the retailers who have recently committed to non-cage supplies only.

It was estimated that some 4.3 million cases of enriched cage eggs produced in 2017 will be displaced as a result of retailers ‘non-cage’ policies. The majority of this seems set to be replaced by barn egg production and between 4.0 and 5.9 million extra barn egg production places will be required in 2025. This is based on retailers’ value line eggs representing an average of between 20% and 30% of total sales at that point.

For free range, some additional production is expected to be needed. This will be due mainly to (i) increasing human population and (ii) expected continued growth in free range between 2017 and 2025. The possibility of total free range sales changing (either increasing or decreasing) in 2025 when customers are offered a choice between free range and barn eggs cannot be ruled out.

If there is sales growth in the free range sector of 5% within these retailers between 2017 and 2025, an extra 1.8 million free range laying hen places will be required. This includes an allowance made for an expected human population growth of 6% over this period. If there is free range growth of 10% or 15% over the same period (2017–2025), an additional 2.7 million or 3.8 million free range laying hen places, respectively, will be required.

Expansion in the free range sector is likely to require a total capital cost of between £58 million (for 1.8 million places) and £122 million (for 3.8 million places), excluding the cost of the land.

Growth and egg laying performance of Japanese quails fed diets containing varying levels of sorghum and maize

A. T. Ijaiya, S. S. A. Egena, O. Omamugho and S. Adio

Federal University of Technology, Minna, Niger State, Nigeria

CONTACT A. T. Ijaiya [email protected]

Applications

Maize was adequately substituted by sorghum as a major energy source in the diets of growing and laying Japanese quails at 100% and 75%, respectively.

Introduction

Cereals form the major sources of energy in poultry diets in the tropical zone (Oluyemi & Ologhobo, 2007). Several energy-contributing ingredients have been assessed as possible substitutes to maize grain in poultry feeding, one of which is sorghum grain. However, the usual high inclusion of maize translate into high cost of feed and pressure on maize by man has been on a progressive increase with prominence being placed on export and diversified use mostly in production of ethanol as alternative source of fuel and flour-based foods. (Doki, 2007). The aim of this research is to assess the growth performance, nutrients digestibility and egg laying performance of Japanese quails fed diets containing varying levels of sorghum as replacement for maize.

Materials and methods

The ethical implications of conducting these trials were considered and the studies deemed fit to be undertaken. Three hundred two weeks old Japanese quails were randomly allotted to 4 dietary treatments in which Red sorghum (KSV-15 variety) from Northern guinea savannah of Nigeria with proximate composition: DM (91.39), CP (10.50), CF (3.91), EE (3.11), Ash (4.42), NFE (78.06) and Tanin (0.01 mg/100 ml) replaced maize at 0, 50, 75 and 100% in diets D1, D2, D3 and D4, respectively, in a completely randomized design, each treatment was replicated thrice. The crude protein was set at 24% with feed and water given ad-libitum. The parameters measured were daily feed intake, daily weight gain, feed conversion ratio and nutrients digestibility. In the laying phase, 180 female Japanese quails were allotted to 4 dietary treatments set at crude protein level of 20% with similar level of replacements of maize as was in the growing phase. The parameters measured were daily feed intake, age at first egg laid, weight of first egg laid, hen-day production and egg quality traits such as egg weight, egg length, egg width, egg shape index, yolk weight, yolk width, shell thickness, yolk index, haugh unit, yolk height, albumen height and albumen weight.

Results

There were no significant (P > 0.05) differences in daily feed intake, body weight gain and feed conversion ratio. However, there were significant (P < 0.05) differences in nutrients digestibility among the treatment groups where birds on 75% replacement had higher digestibility in crude protein and NFE than other dietary groups. The value of NFE for D₂ is significantly lower compared to the other diets and this may be attributed to better nutrient digestibility of the diet. Despite some differences in nutrient digestibility there was no effect measured on performance (Table 1). There were significant (P < 0.05) differences in the daily feed intake, hen-day production and all the egg quality traits with birds on 75% replacement having better egg quality traits and hen-day production.

Table 1. Performance of Japanese quails fed diets containing varying levels of sorghum grain inclusions and nutrients digestibility of the diets.

Parameters	D1	D2	D3	D4	SEM
Initial body weight (g)	39.58	39.58	39.58	39.58	0.00
Final body weight (g)	144.00	140.27	142.27	147.50	1.28
Daily weight gain (g)	3.73	3.56	3.69	3.85	0.05
Feed intake (g)	556.05	528.75	554.17	576.67	13.99
FCR	5.32	5.58	5.36	5.35	0.12
Nutrients digestibility (%)
Dry matter	88.23^b	88.76^b	87.14^b	93.23^a	1.02
Crude protein	85.35^b	85.65^a	85.77^a	83.48^b	0.33
Crude fibre	64.19	59.04	62.39	59.48	1.06
Ash	79.36^a	75.56^ab	71.88^b	71.87^b	1.07
Ether extract	86.50	84.28	91.41	71.43	4.32
NFE	74.31^a	66.86^b	74.76^a	73.33^a	1.01

No common lettering indicates that there is a significant difference between treatments (P<0.05).

Conclusion

Maize could be replaced completely with sorghum in the diets of growing Japanese quails, while up to 75% replacement in the diets of laying Japanese quails without any deleterious effect on growth performance, egg production or egg quality traits.

References

• Doki, T. (2007). In T. Abatan (Eds.), Saturday Independent (Vol. 1, no. 86, p. 4).
   Google Scholar
• Oluyemi, J. A., & Ologhobo, A. D. (2007). Proceedings of 12th Annual Conference of Animal Science Association Nigeria (pp. 96–103). Lagos, Nigeria.
   Google Scholar

Evaluation of oats with varying husk inclusion on performance, energy and nitrogen retention in broilers

D. V. Scholey^a, A. Marshall^b, S. Cowan^b and E. J. Burton^a

^aNottingham Trent University, Nottingham, UK; ^bIBERS, Aberystwyth, UK

CONTACT D. V. Scholey [email protected]

Application

Oats with up to 30% husk can support bird performance comparatively with wheat at up to 30% dietary inclusion, which may have cost implications for diet formulation and oat processing.

Introduction

Oats are not widely fed to broilers in the UK due to their husk content (around 27%, McDonald et al., 2002) resulting in high fibre and comparatively low energy compared with wheat. Dehulled oats are available, but these can be costly to produce and leaves a substantial volume of oat husks, which need to be utilised effectively. A trial was designed to examine the impact of replacing 30% of dietary wheat with oats with varying levels of oat husk, on performance and retention of nitrogen and energy in broilers. In this study, oat husks were added to dehulled oats to give specific graded husk inclusion.

Materials and methods

A total of 320 male Ross 308 birds were raised on wheat/soya mash diets with 2 phases (starter, d1–21; finisher d22–35) and 5 treatment diets. Diets were formulated commercially for the age and strain of the birds and the study was approved by the NTU college ethics committee before beginning. The control diet contained no oats and treatments replaced 30% of wheat in this control diet with dehulled oats combined with oat husks – to give inclusion levels of 3%, 10%, 20% and 30% husk in the oat portion of the diets. Oats and husks were all ground through a 3 mm screen before incorporation into diets. All diets also contained 0.5% TiO₂ as an inert marker. Eight pens per treatment (5 birds per pen) were raised to d35 in 0.64 m² pens with shavings as litter. Feed and water were available ad libitum. Bird weight, bodyweight gain (BWG), feed intake (FI) and subsequently FCR were recorded weekly for each pen. On d35, excreta were collected from each pen, dried and ground before analysis for Nitrogen (via Dumas), Gross energy (via bomb calorimetry) and TiO₂ content (by the method of Short et al., 1996) to enable calculation of AME and AMEn. Gizzards were removed from one bird per pen, emptied, rinsed with water and weighed to quantify gizzard development. Data were analysed by ANOVA using SPSS (v24) with significance level determined at P < 0.05.

Results

The results of bird performance, AME, AMEn and gizzard development can be seen in Table 1. High husk diets (30%) reduced FCR, AME and AMEn, increased gizzard weight, but did not adversely affect BWG or FI.

Table 1. Bird performance from d0 to 35 and AME, N retention, AMEn and gizzard weights of birds at d35 fed diets with graded inclusion of oat husks.

Diet	BWG/bird (g)	FI/bird (g)	FCR d0–35	AME (MJ/kg)	N retention g/kg diet	AMEn (MJ/kg)	Gizzard weight (g)
Control - no oat	2278	3412	1.50^ab	13.04^ab	19.28	12.38^ab	26.1^b
30% husk	2343	3665	1.56^b	11.14^b	18.46	10.50^b	32.9^a
20% husk	2164	3384	1.57^b	12.10^ab	18.55	11.46^ab	28.6^ab
10% husk	2314	3454	1.49^ab	13.23^ab	19.93	12.55^ab	28.2^ab
3% husk	2331	3453	1.48^a	13.68^a	19.15	13.02^a	27.0^b
SEM	52.1	74.3	0.024	0.56	0.78	0.55	1.06
P value	nsd	nsd	<0.001	<0.001	nsd	<0.001	<0.001

No common lettering indicates that there is a significant difference between treatments (P<0.05).

Conclusion

Retaining 74% of oat husks (i.e. 20% husk diet) at a 30% inclusion rate does not negatively impact AME. Furthermore, introducing 30% husks (more than found naturally occurring) did not significantly influence BWG. There is a correlation between husk inclusion and gizzard weight, suggesting the latter reflects utilisation of the lignocellulose content of the diet breaking down the fibres into carbohydrate oligos and monomers. Carbohydrate oligos generated may confer prebiotic benefits to the birds and therefore have the potential to improve bird gut health. Further work is needed to investigate the effect of pelleted diets with oat husk inclusion and the impact on gut microflora.

Acknowledgements

The authors acknowledge the support of Innovate UK, and the partners of the Endevor project (Project number 101827) Senova Ltd, Oat Services Ltd, Phytatec Ltd, IIT Ltd, IBERS Aberystwyth University for providing oats, and GLW feeds Ltd for their valuable input into trial planning. Mr A Waller is gratefully thanked for his assistance with feed formulations.

References

• McDonald, P., Edwards, R. A., Greenhalgh, J. F. D. and Morgan, C. A. (2002). Animal Nutrition, 572–573.
   Google Scholar
• Short, F. J., Gorton, P., Wiseman, J. and Boorman, K. N. (1996). Animal Feed and ScienceTechnology, 59, 215–221.
   Web of Science ®Google Scholar

Egg quality is improved when a 300 ppm calcium pidolate supplement is added to the layer diet from 50 to 70 wks

M. M. Bain^a, T. Parkin^a, R. Gill^b, D. Brass^b and B. Pollet^c

^aUniversity of Glasgow, UK; ^bLakes Free Range Company, Penrith, UK; ^cDietaxion, S.A.S, France

CONTACT M. M. Bain [email protected]

Application

Free range flocks (n = 4) receiving a calcium pidolate supplement had fewer % Seconds (0.89%; P < 0.001) and more % Large graded eggs compared to flocks receiving no supplementation (n = 4). Eggshell breaking strength, shell weight and shell colour were also improved in the supplemented flocks. For producers this means more ‘saleable’ eggs, which probably justifies the additional cost of supplementing the diet with calcium pidolate, especially when laying flocks are to be kept for longer.

Introduction

Calcium pidolate (a highly soluble, absorbable salt with excellent gastrointestinal tolerance) is claimed to have a positive impact on egg (in lay) and bone quality (in rear). Supporting evidence however is limited (Agblo & Duclos, 2011; Valderrama & Roulleau, 2013). Additional data from commercial scale trials are needed to help producers make a decision about whether to use calcium pidolate or not, as its use comes at a significant cost. The aim of this study was to vigorously test the hypothesis that providing laying hens with a 300 ppm calcium pidolate supplementation from 50 wks of age improves egg quality in free range (FR) flocks at 70 wks of age.

Materials and methods

Eight commercial FR flocks located at 4 different study sites were used in this study. At each site there was two identical sheds with flocks of the same stocking density (12–16,000), genotype and age. One flock at each site was given a 300 ppm calcium pidolate supplement to the standard ration (treatment) from 50 to 70 wks, the other flock received just the standard ration (control). Egg grading data were collated weekly for each flock from 45 wks to 50 wks (baseline) and 51–70 wks of age (post-intervention). Egg quality (egg weight (g), dynamic stiffness (N/mm), breaking strength (N), shell colour (%ref), shell thickness (mm) and shell weight (g)) was assessed on 120 eggs per flock every 5 weeks from 45 wks to 70 wks of age. Data were analysed using multivariable linear regression models with the 4 study sites serving as replicates. Age effects were included in all models and ‘site’ (n = 4) was included as a random effect variable to account for between ‘site’ variations. For the egg grading and egg quality datasets, two sets of models were developed: the first model (Model 1) compared the baseline data with post-intervention data for control or treatment groups; the second model (Model 2) compared the post-intervention data for the treatment group with the control group with a statistical significance declared at P < 0.05. The ethical implications of conducting this trial were considered and the trial deemed fit to be undertaken.

Results

In Model 1a significant post intervention reduction in average egg weight (−0.8 g; P = 0.025) was observed in the control group. For the egg quality data set, significant post-intervention reduction was observed in both treatment and control groups for breaking strength (Treatment: −5.5 N, P < 0.001; Control: −6.2 N, P < 0.001) and shell colour (Treatment: −10.73%Ref, P < 0.001; Control: −11.48%Ref, P < 0.001). Model 2 compared the post-intervention data sets with each other. This revealed a significant increase in the % Large eggs (+1.4%, P < 0.001) and a significant reduction in % Seconds (−0.89%, P < 0.001) in the Treatment group. Eggshell breaking strength (+0.7 N; P = 0.004), shell weight (+0.048 g; P = 0.014) and shell colour (+0.75%; P < 0.001) were also significantly improved in the post-intervention treatment group.

Conclusion

For the producer fewer % second’s means more ‘saleable’ eggs and therefore may benefit the additional cost of adding calcium pidolate to the layer ration from 50 to 70 wks of age. The improvement in breaking strength although subtle could also explain why more large eggs remained intact through the handling and grading process in this study. Bone health status was also compared in this study but no post-intervention treatment effects were observed (data not presented). According to the supplier, to improve bone health in older flocks the focus of attention should be the rearing period when the medullary bone reserves are first forming.

Acknowledgements

This study was funded through a Sainsbury’s ‘Big Data’ Agriculture Research and Development Grant (2014–15). The authors would like to thank Dietaxion for supplying the calcium pidolate.

References

• Agblo P., & Duclos, J. (2011). Proceedings of Research on Poultry. Tours, 29–30 March 2011.
   Google Scholar
• Valderrama M., & Roulleau, X. (2013). Proceedings of Research on Poultry and Waterfowl Foie Gras. La Rochelle, 26–28 March 2013.
   Google Scholar

Favourable genetic parameters for the improvement of cuticle deposition on eggs

I. C. Dunn^a, P. W. Wilson^a, M. M. Bain^b, A. Jones^c, F. Quinlan-Pluck^c, G. O. S. Williams^c, W. Icken^d and V. Olori^e

^aThe Roslin Institute, Midlothian, UK; ^bThe University of Glasgow, UK; ^cThe University of Edinburgh, UK; ^dLohmann Tierzucht, Cuxhaven, Germany; ^eAviagen, Midlothian, UK

CONTACT I. C. Dunn [email protected]

Application

Implementation of selection for cuticle deposition should reduce the incidence of contaminated eggs, reduce the vertical transmission of potentially pathogenic organisms and help to improve biosecurity.

Introduction

The cuticle is important to the protection of eggs from bacteria during hatch and in the nest. The cuticle is an invisible glycosylated protein layer that covers the outside of the eggshell; it forms both a physical barrier to the transmission of microorganisms and contains proteins that are likely to be antimicrobial. Previously we have demonstrated that genetics is an important component of the variability of the cuticle deposition and that there was clear difference between the extremes of the population in the likelihood of bacteria penetrating an egg (Bain et al., 2013). In the present study, we wanted to extend our previous study, in which we observed that around 30% of the variation in cuticle deposition was genetically determined in a Rhode Island Red line, to other genetically distinct chicken lines and to determine the ability to predict cuticle deposition later in the laying period.

Materials and methods

Three distinct genetic lines were used in the study: Line 1, a Rhode Island Red pure line that contributes to the male line used to produce Lohmann Brown commercial layers (Lohmann Tierzucht GmbH); Line 2, a white leghorn pure line that is used in the production of LSL commercial layers (Lohmann Tierzucht GmbH); Line 3, A purebred broiler line (Aviagen Ltd). To estimate the genetic parameters, between 914 and 1459 hens were used, depending on the line, and 2 eggs per hen at the same age. Cuticle deposition was measured using staining, with either MST cuticle blue or our own preparation of tartrazine/lissamine green as previously described (Wilson et al., 2017), and spectrophotometric measurement of the absorbance of the egg surface at 640 nm, before and after staining. The estimated genetic parameters are based on the difference between both measurements. Heritabilities and genetic correlations were made using variance components analysis from REML using Genstat v13.

Results

In the same Rhode Island Red line as used in our first study (Line 1), heritability for cuticle deposition was 0.49 ± 0.12 and 0.43 ± 0.12, at 32 and 50 weeks of age, respectively. Importantly, it has been possible to replicate the observations in genetically distinct lines of poultry. In a line of broilers (Line 3), the estimate of heritability for cuticle deposition was 0.24 ± 0.04, and in a white leghorn line (Line 2) 0.31 ± 0.10. As with many egg traits, the repeatability of the measurement is relatively high when measuring eggs from the same hen. This was reflected in a high genetic correlation, with an estimate of 0.96 ± 0.04, between the measurement of cuticle deposition taken from the same Rhode Island Red hens at 32 and 50 weeks of age.

Conclusion

The heritability estimates are moderate in all the lines examined in this study; this confirms the validity of the original estimates made in a single line. The high genetic correlation between the observation made early in production with that made later in production, indicates that one measurement should be sufficient to predict future performance. We did not observe any significant negative genetic correlations with production traits. These results reinforce that the cuticle measurement could be incorporated advantageously into breeding programmes. The particular benefit will be the reduction in vertical transmission of pathogenic organisms and the opportunity to improve biosecurity.

Acknowledgements

The work was funded by the BBSRC, Lohmann Tierzucht and Aviagen through the BBSRC LINK grant BB/K0070921/1 ‘Cute-Egg’. The Roslin Institute is funded with BBSRC institute strategic programme grants BB/J004316/1 & BBS/E/D/30002276.

References

• Bain, M. M., McDade, K., Burchmore, R., Law, A., Wilson, P. W., Schmutz, M., … Dunn, I. C. (2013). Animal Genetics, 44, 661–668.
   Google Scholar
• Wilson, P. W., Suther, C. S., Bain, M. M., Icken, W., Jones, A., … Dunn, I. C. (2017). Biology of Reproduction, 96, 39–49.
   Google Scholar

The effect of ranking laying hens by feed efficiency on the quality and nutrient composition of eggs

Y. Akter^a, S. Greenhalgh^a, M. D. Islam^a, D. Anene^b and C. J. O’Shea^b

^aUniversity of Sydney, Australia; ^bUniversity of Nottingham, Leicestershire, UK

CONTACT C. J. O’Shea cormac.o’[email protected]

Application

Hens ranked as highly feed efficient (HFE) during early lay produced eggs of greater albumen weight, height and Haugh Unit when compared with highly inefficient hens (LFE). Further, the fatty acid profile of the yolk from HFE had increased PUFA:SFA and decreased markers of lipid peroxidation. These results provide some insight into the relationship between hen feed efficiency (FE) and egg composition.

Introduction

Egg quality and composition, and FE are important production traits for laying hens. Various heritability studies have shown there is considerable variation in FE in poultry, which has undesirable consequences for flock uniformity. Studies exploring the underlying physiology of variation in FE in food production animals have shown involvement from many factors including mature bodyweight, immune status, feeding behaviour, digestive physiology and the composition of the enteric microbiota (Vigors et al., 2016). These factors may also have consequences for food quality. However, there has been little research examining the relationship between variation in feed efficiency and the subsequent quality and nutritional composition of the egg. It was our hypothesis that feed inefficient hens may produce eggs of inferior quality and nutritional composition.

Materials and methods

Feed conversion efficiency (FCR) is defined here as the ratio of feed intake per unit of egg mass in laying hens. From an initial screening phase (7 weeks) involving 140 Isa Brown layers (28 week old), the 10 most efficient (FCR < 1.99 ± 0.05) and the 10 least efficient (FCR > 2.30 ± 0.05) hens were identified and designated as high feed efficiency (HFE) and low feed efficiency (LFE) groups, respectively. Internal and external quality and yolk composition were determined on three consecutive days on fresh eggs (n = 10 per group). Egg quality assessment was carried out on eggs as described by Browning and Cowieson (2015). Data were analysed using the generalised linear model procedure of SAS (SAS Institute) with feed efficiency group as the main effect. Means were separated using the Tukey–Kramer method.

Results

Hens ranked as HFE and LFE during the screening phase maintained FE status during egg quality assessment, and egg mass was unaffected by FE ranking (Table 1). Birds in the HFE cohort had significantly higher albumen weight, albumen height and Haugh unit compared with the LFE ranked hens, whereas the eggs from the LFE group had heavier yolk than the HFE group (data not presented). The relative proportions of palmitic, stearic acid, oleic acid and monounsaturated fatty acids (MUFA) were lower while the total PUFA and the ratio of PUFA:SFA values were higher in the HFE group when compared with the LFE group of eggs. Biomarkers of lipid peroxidation (TBARS) were higher in the yolk of LFE birds when compared with the HFE birds (Table 1).

Table 1. The effect of feed efficiency on body weights and performance of layer hens.

Measurement	HFE	LFE	SEM	P value
Feed intake (g/d)	127	143	2	0.001
Egg mass (g/d)	64.7	62.8	1.1	0.230
Feed conversion ratio (g/g)	1.9	2.3	0.05	0.002
Yolk PUFA:SFA	0.50	0.30	0.04	0.036
Yolk TBARS mg MDA/g	0.26	0.38	0.03	0.015

HFE: high feed efficiency group; LFE: low feed efficiency group.

No common lettering indicates that there is a significant difference between treatments (P<0.05).

Conclusion

Variations in hen FE were influenced by feed intake rather than egg output. Hens ranked as HFE and LFE had different internal egg technical quality and composition as this relates to albumen and yolk. HFE hens had greater proportions of polyunsaturated fatty acids and lower concentrations of markers of lipid peroxidation (TBARS) in yolk when compared with LFE hens. The results of this study provide some evidence of a relationship between FE and egg quality.

Acknowledgements

The technical assistance at the Poultry Research Foundation, University of Sydney, is acknowledged and appreciated.

References

• Browning, L., & Cowieson, A. J. (2015). Journal of the Science of Food and Agriculture, 95, 1080–1087.
   PubMed Web of Science ®Google Scholar
• Vigors, S., Sweeney, T., O’Shea, C. J., Kelly, A. K., O’Doherty, J. V. (2016). Animal, 10, 1848–1855.
   Google Scholar

Quantitative assessment for the risk of recrudescence of avian influenza in caged layer houses following depopulation: the effect of cleansing, disinfection and dismantling of complex equipment

P. Gale, S. Sechi, V. Horigan and L. Kelly

Animal and Plant Health Agency, Weybridge, UK

CONTACT P. Gale [email protected]

Application

This work provides risk-based evidence for the control of avian influenza following an outbreak, with specific reference to cleansing and disinfection (C&D). It can be used by policy-makers and industry in their decision-making. Although focusing on avian influenza and caged layers, the methods are applicable to other poultry species and pathogens.

Introduction

Avian influenza (AI) virus is notifiable in the United Kingdom (UK) and following an outbreak of disease, control measures are put in place to prevent further spread. These control measures are based on the European Commission (EC) Avian Influenza Directive (2005/94/EC), an essential part of which is the C&D of infected premises (IPs). Cleansing and disinfection includes preliminary and secondary C&D and within the UK, the dismantling of complex equipment during secondary C&D is also required. Qualitative and quantitative risk assessments were undertaken to assess the risk of re-infection in a caged layer house under different C&D scenarios. This paper presents the results of a desk-based modelling study based on literature and expert opinions to quantitatively assess the risks.

Materials and methods

The model assesses the probability of infection in a sentinel flock (recrudescence) given C&D procedures have been carried out. The inverse of this probability was used to describe results, that is, the number of repopulated flocks expected before infection is reintroduced. Three C&D scenarios were considered namely (i) preliminary C&D alone, (ii) preliminary C&D plus secondary C&D without dismantling and (iii) preliminary C&D plus secondary C&D with dismantling. The source-pathway-receptor framework (as applied previously to modelling environmental risks, for example the risks to grazing livestock from the application of composted catering waste (Gale, 2004)) was used to construct the model and parameterisation was based on the three C&D scenarios. Probability distributions were used to describe parameters for which there was recognised variability between premises (the time between depopulation and restocking) or uncertainty due to lack of information (the rate of by-pass, that is the proportion of virus that C&D does not reach). The model was constructed using the R Studio and R Shiny statistical software packages(RStudio®, Shiny®).

Results

Based on the model structure, assumptions and parameter estimates obtained from the literature and expert opinion, the risk assessment estimates that the median number of repopulated flocks before recrudescence is 12,500, 200,000 and 1,000,000 under C&D scenarios (i), (ii) and (iii), respectively. These results indicate that for AI in caged layers including secondary C&D without dismantling reduces the risk 16-fold compared to preliminary C&D alone. Dismantling has an additional, although smaller, impact, reducing the risk by a further 5-fold and thus around 80-fold in total.

Conclusion

Overall, the probability of recrudescence of AI in caged layers following depopulation and C&D can be considered very low. Secondary C&D has a small benefit over preliminary C&D alone and dismantling has an even smaller additional benefit. The level of by-pass is a key source of uncertainty.

Acknowledgements

This worked was funded by the Poultry Health and Welfare Group. The authors thank the poultry experts and farms who provided valuable information to guide model structure and estimate model parameters.

Reference

• Gale, P. (2004). Veterinary Record, 155, 77–82.
   PubMed Web of Science ®Google Scholar

Growth performance and behaviour of broiler chicken reared under two different light bulb sources and distances

O. O. Adeleye, L. T. Egbeyale, O. Ayo-Ajasa, M. O. Abatan, A. W. Abdkareem, A. O. Odukoya and O. E. Akinsola

Federal University of Agriculture, Abeokuta, Nigeria

CONTACT L. T. Egbeyale [email protected]

Application

Broiler birds raised under incandescent (ICD) and compact fluorescent bulbs (CFL) suspended at 85 and 170 cm showed similar growth performance; however, their behaviour differs with a higher incidence of pecking observed in birds raised under the incandescent bulbs. Pecking in poultry industry increases mortality and reduces meat quality.

Introduction

The use of artificial lighting has been reported to be of immense benefit to poultry industry as opined by Kim et al. (2013) that light component a major environmental stimulus affecting growth rate and behaviour; its manipulation is an important management tool affecting broiler production and well-being. However, there is a dearth of knowledge on the impact of different light sources at varying bulb distances above the ground on growth performance as well as the behaviour patterns of broiler chickens in Nigeria. The two most available bulbs in Nigeria are the incandescent and compact fluorescent bulbs. Therefore, this study aimed at investigating the growth and behavioural response of broiler chickens reared under the incandescent and compact fluorescent bulbs at different distances from the ground level.

Materials and methods

A total of 288 day-old broiler chicks of Arbor Acre strain were randomly allotted into 4 treatments, each comprising of 6 replicates of 12 birds each. During daytime, all the birds in the 4 treatments were exposed to 10–11 h daylight while at night T1 was exposed to 8 h Incandescent bulb (ICD - 40lux) lighting at 85 cm from the ground level, T2, 8 h of incandescent bulb lighting at 170 cm from the ground level, T3, 8 h compact fluorescent lamp (CFL - 27lux) lighting at 85 cm from the ground level and T4, 8 h CFL lighting at 170 cm from the ground level. The birds were fed commercial broiler starter containing 2800 Kcal/KgME and 21%CP from 0 to 4 weeks and finisher feed containing 2900 Kcal/KgME and 18%CP from 5 to 7 weeks. Data were collected on the growth parameters which include average feed intake, average water intake, average weight gain and feed conversion ratio at week 4 and week 6 of age. At week 6, the birds were observed using 2 Closed-Circuit Television (CCTV) cameras which were installed in each treatment pen and 24 birds were observed (8 h/d) per treatment for 7 days. Parameters observed were feeding, drinking, dustbathing and pecking behaviours (pecking other birds). All data collected were subjected to one-way analysis of variance using Minitab 16 via a Generalised Linear Model and the significant means were separated using Tukey’s test of the same statistical package

Results

Growth indices measured were not influenced by the interaction between light bulb and distance at both phases while the 4 behavioural parameters measured were significantly influenced (Table 1).

Table 1. Interaction effects of two different light bulbs and distance on growth and behaviour of broiler birds.

	ICD		CFL
Parameters	85 cm	170 cm	85 cm	170 cm	SEM	P value
Avg. weight (g/bird) (wk 4)	1035.0	1056.0	1024.0	1011.0	14.98	0.80
Avg. water intake (litre/bird) (wk 4)	1.4	1.3	1.3	1.3	0.03	0.36
Avg. weight (g/bird) (wk 4)	382.6	405.9	372.2	361.1	15.10	0.26
Average feed intake (g/bird) (wk 4)	876.9	715.8	860.4	836.4	77.7	0.39
FCR (wk 4)	2.3	1.8	2.3	2.4	0.21	0.18
Avg. weight (g/bird) (wk 6)	1873.0	1875.0	1866.0	1829.0	33.16	0.57
Avg. water intake (litre/bird) (wk 6)	2.0	2.1	2.0	2.0	0.05	0.55
Avg. weight gain (g/bird) (wk 6)	402.1	395.5	394.3	364.0	31.61	0.71
Average feed intake (g/bird) (wk 6)	961.6	906.9	934.0	893.8	19.85	0.72
FCR (wk 6)	2.4	2.5	2.4	2.5	0.20	0.86
Feeding frequency/h (wk 6)	42.5^ab	39.6^bc	30.3^c	45.5^a	1.50	<0.01
Drinking frequency/h (wk 6)	42.8^a	33.1^b	20.8^c	35.2^b	1.43	<0.01
Pecking frequency/h (wk 6)	11.2^b	20.5^a	1.9^c	10.7^b	0.95	<0.01
Dust bathing frequency/h (wk 6)	0.1^b	0.2^b	1.0^a	0.4^b	0.11	<0.01

Conclusion

Broiler birds can be raised under the two light sources and distances. However, the high frequency of pecking may discourage the use of incandescent bulb for broiler production.

Acknowledgements

We acknowledge the support of Mr Seyi Jegede, Abiala O.E, Ogunkoya O.O, Adeyemo E.O, Faniyi O.O and Ajose A.K for their contribution during data collection.

Reference

• Kim, M.J., Parvin, R., Mushtaq, M. M. H., Hwangbo, J., Kim, J. H., Na, J. C., Kim, D. W., Kang, H. K., Kim, C. D., Choi, K. O., Yang, C. B. and Choi, H. C. (2013). Poultry Science, 92, 1461–1466.
   PubMed Web of Science ®Google Scholar

Superoxide dismutase activity in the chicken gut

P. F. Surai^a,b, I. I. Kochish^b and S. O. Shapovalov^c

^aTrakia University, Stara Zagora, Bulgaria; ^bMoscow State Academy of Veterinary Medicine and Biotechnology named after K.I. Skryabin, Moscow, Russia; ^cResearch-Testing Center Cherkizovo, v. Yakovievskoye, Moscow, Russia

CONTACT P. F. Surai [email protected]

Application

Superoxide dismutase is key antioxidant enzyme in the chicken intestine preventing oxidative damage in stress conditions and participating in adaptation to various stress conditions. Interestingly, it can be regulated by various nutrients.

Introduction

Poultry production is associated with a range of stresses including environmental (high or low temperature, dust), technological (chicken placement, grading, weighing), nutritional (mycotoxins and oxidized fat) and internal/biological (fast growth, microbial or viral challenge) stresses. It was proven that at the molecular level most of stresses are associated with overproduction of free radicals and oxidative stress. Therefore, during evolution antioxidant systems have been developed in animal body to prevent possible detrimental consequences of oxidative stress. The antioxidant defence network in the tissues is very complex and includes natural antioxidants (e.g. vitamins E and C, glutathione, thioredoxin, antioxidant enzymes), transcription factors (Nrf2 and NF-κB) and vitagenes. This network is responsible for adaptation to stress by upregulating various genes and increasing synthesis of protective molecules, including heat shock proteins (to maintain protein integrity), antioxidant enzymes, including superoxide dismutase (SOD), glutathione peroxidase and other selenoproteins (thioredoxin reductase, methionine sulfoxide reductase) and catalase (Surai, 2016). Antioxidant–prooxidant balance in the chicken gut is of great importance for maintenance of a healthy gut and deserve more attention. Superoxide dismutase was characterised in different chicken tissues (Surai, 2016) and included into the vitagene family (Surai & Fisinin, 2016). However, there is no data available on SOD activity in the gut of adult birds. Therefore, the aim of this study was to evaluate total SOD activity in different segments of the chicken gut.

Materials and methods

An experiment was conducted with Lohman Brown layers at age of 34 weeks (peak of egg production) which were fed on a commercial wheat–barley diet balanced in all nutrients in accordance with Lohman recommendations. All other technological parameters were also within the recommended levels. Ten layers with an average for the age body mass and productivity were sacrificed in accordance with the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health and the intestinal tract was collected and divided into duodenum, jejunum, ileum, ceca and colon. Total SOD activity and lipid peroxidation (as malondialdehyde) in mucosa of each gut segment were determined spectrophotometrically using kit systems supplied by Randox Ltd. (Crumlin, UK) and Sigma-Aldrich (USA), respectively. Statistical analysis was performed by One-way ANOVA and t-test.

Results

There is a significant difference in total SOD activity between different segments of the gut. Based on the SOD activity the laying hen intestinal segments can be placed in the following descending order: duodenum>jejunum = ileum≫ceca>colon. From one hand, the total SOD activity in the duodenum was significantly (by 40%, P < 0.05) higher than that in jejunum or ileum. On the other hand, the total SOD activity in the ceca was shown to be significantly (by 32%, P < 0.05) lower than that in jejunum or ileum, but substantially higher (by 24%, P < 0.05) in comparison to that in the colon. Interestingly, lipid peroxidation (MDA) was found to be highest in jejunum and the order of the intestinal segments in accordance with MDA level (jejunum>duodenum>ileum>ceca = colon) is not the same as for SOD, reflecting importance of other protective mechanisms in the intestine (beyond SOD) responsible for antioxidant defences. Indeed there is a need for more detailed evaluation of the antioxidant system of the chicken gut depending on age, nutrition and stress. It would be also very important to study a relationship between antioxidant defences and microbiota in the chicken gut to understand molecular mechanisms of the maintenance of healthy gut in stress conditions.

Conclusion

There are site-specific antioxidant defence mechanisms in the chicken gut and the highest SOD activity was found in the duodenum while the lowest level of lipid peroxidation was shown in the ceca and colon.

Acknowledgements

This work is supported by a grant of the Government of Russian Federation (Contract No. 14.W03.31.0013).

References

• Surai, P. F. (2016). Journal of Animal Research and Nutrition, 1, 1–8.
   Google Scholar
• Surai, P. F., & Fisinin, V. I. (2016). World’s Poultry Science Journal, 72, 793–804.
   Web of Science ®Google Scholar
• Surai, P. F., & Fisinin, V. I. (2005). Journal of Veterinary Science and Medicine, 3, 1–16.
   Google Scholar

Investigation into the effect of semi-synthetic diets on the intestinal mucin layer of broilers

S. Amir, D. V. Scholey, M. Le Bon, E. J. Burton and C. Turkura

Nottingham Trent University, Nottingham, UK

CONTACT E. J. Burton [email protected]

Application

Semi-synthetic diets can be used to assess digestibility of nutrients in broilers without concern of altered mucin production confounding results.

Introduction

The mucus layer covering the gastrointestinal tract acts as a medium for protection, lubrication and transport between the luminal contents and epithelial cells. There appears to be a strong link between diet and synthesis of the mucus layer (Kidd & Tillman, 2016; Smirnov et al., 2004). Semi-synthetic diets (SSD) are often selected for digestibility experiments in poultry. However, these diets raise the question of whether the results obtained from the SSD are valid for phytate-containing diets used in commercial feeding of broilers (Shastak et al., 2014). SSD are less palatable to poultry and studies using SSD have reported reduced feed intake compared to conventional diets but it appears no examination on the effect of SSD on mucin layer has been reported to date. Therefore, the objective of this study was to compare the mucin layer of birds fed three graded levels of semi synthetic ingredients (50:50 starch/dextrose) replacing standard wheat (STW) in the base diet.

Materials and methods

The study received ethical approval prior to commencement from the University’s School Ethical Review group. A total of 192 male Ross 308 broiler chicks were placed in 24 deep litter pens with wood shavings on the day of hatch. Each pen held 8 chicks. Feed and water were given ad libitum via feed troughs and nipple drinkers. A commercially available starter diet was fed to all the birds from day 0–14. On day 15, the birds (8 pens per diet) were switched to treatment diets manufactured in house. Diet A (20% wheat and 45% starch-dextrose), Diet B (40% wheat and 25% starch-dextrose) and Diet C (60% wheat and 5% starch-dextrose). Remaining ingredients were fixed across all diets to meet the nutrient requirements of the age and strain of bird, with protein sources of Rapeseed meal (9%) and Hi-Pro© Soya meal (21%). On day 20 one bird per pen was weighed and then euthanised for mucin analysis. An approximately 1 cm² section of the ileum was dissected and its mucus adherent layer thickness analysed using the method described by Smirnov et al. (2004) with a small adaptation: the 1 cm² of excised tissue was weighed and results expressed as µg Alcian Blue/g of intestinal tissue for increased accuracy. Data were analysed via one-way ANOVA using IBM SPSS version 23, with a statistical significance declared at P < 0.05.

Results

There was no significant difference in the mucin layer thickness (P = 0.834) of birds fed diets containing differing levels of synthetic ingredients in place of wheat (Figure 1).

Figure 1. Mucin adherent layer thickness of birds fed different levels of semi synthetic ingredients.

Conclusion

The results from this study suggest that inclusion of SS ingredients in the diet have no effect on the amount of mucus secreted by the intestinal epithelium.

Acknowledgements

Technical support from the NTU poultry research unit team is gratefully acknowledged.

References

• Kidd, M., & Tillman, P. B. (2016). Animal Feed Science and Technology, 221, 314–322.
   Google Scholar
• Shastak, Y., Zeller, E., Witzig, M., Schollenberger, M., & Rodehutscord, M. (2014). Poultry Science, 93, 2548–2559.
   PubMed Web of Science ®Google Scholar
• Smirnov, A., Sklan, D., & Dni, Z. (2004). The Journal of Nutrition, 134, 736–742.
   PubMed Web of Science ®Google Scholar

Dietary prebiotic, probiotic and synbiotic supplementation on the immune function of meat chickens

A. Alsudani, S. Ali, M. Le Bon, D. V. Scholey, G. Manning and E. J. Burton

Nottingham Trent University, Nottingham, UK

CONTACT A. Alsudani [email protected]

Application

Dietary supplementation with probiotics, prebiotics, or synbiotics has been shown to positively manipulate or maintain the microbial community in both human and animal studies, thus saving the energy required to mount an immune response.

Introduction

Prebiotic, probiotic and synbiotic supplements can cause a shift in the gastrointestinal tract (GIT) population in favour of beneficial bacteria such as Lactobacillus sp and Bifidobacterium sp) (Mookiah et al., 2014)). This in turn can positively affect immune function by regulating cytokine expression especially in the intestinal cells (Isolauri et al., 2001).The objective of this study was to investigate (both singly and in combination) the effects of a plant-derived prebiotic and a mix of a novel 6 isolates of Lactobacillus isolated and screened at Nottingham Trent University as candidate probiotic agents on the immune function of meat chickens by measuring the mRNA expression of IFN, IL-6 and IL-10.

Materials and methods

Jerusalem artichoke plant was dried and ground as a prebiotic, while the probiotic was produced from 6 isolates of Lactobacillus that were isolated and cultured from a small flock of healthy free-range chicken, and screened in vitro as viable probiotic agents (details not presented here) before freeze-drying into a powder using dried skimmed milk as a carrier. For chicken trial, chicks at day 1 were divided into 6 replicates of 6 treatments (T) which were, T1 (control) basal diet only, T2 (basal diet + 5%prebiotic), T3 (basal diet + 10%prebiotic), T4 basal diet+(probiotic mix of 6 isolates of Lactobacillus spp.), T5 (basal diet + 5%prebiotic + probiotic) and T6 (basal diet +10%prebiotic + probiotic). At the ages 7, 21 and 42 of the study, 6 birds/treatment were sacrificed by cervical dislocation and tissues from ileum were excised and stored in RNA later in −80°C until further processes. RNA was extracted from the tissue according to the Qiagen RNA extraction kit protocol and the quality checked by Nanodrop. Afterward cDNA was synthesised by using a Bio-Rad iScript™ cDNA Synthesis kit. qRT-PCR primers were selected using National Centre for Biotechnology Information (NCBI) for sequences. RT-PCR was performed using a Bio-Rad CFX384 instrument and iQ™ SYBR® Green Supermix kit. Results were analysed by one way ANOVA and comparison was performed using the SPSS statistical software (version 23.0, SPSS Inc.,). Ethical approval was granted by the Nottingham Trent University, School of ARES ethical review group.

Results

Results of this study in Table 1 show that supplements of prebiotic, probiotic and synbiotic have shown significant effects on the mRNA expression of IFN-γ, IL-10 and IL-6 at day 7, also at day 21 mRNA expression IL-10 and IL-6 were affected by the supplements. Meanwhile, there were no effects at day 42 on the mRNA expression of these three cytokines.

Table 1. Fold change (mean ± S.E.) of mRNA expression of IFN-γ, IL-10 and IL-6 in the ileum tissue at day 7, 21 and 42.

Cytokine	Age	Treatments						SIG.
		T1	T2	T3	T4	T5	T6
IFN-γ	Day7	1 ± 0.0	1.39 ± 0.65	1.18 ± 0.86	1.25 ± 0.64	1.97 ± 1.02	1.05 ± 1	N.S
	Day 21	1 ± 0.0^a	0.67 ± 0.12^b	0.55 ± 0.09^b	0.59 ± 0.17^b	0.65 ± 0.26^b	0.63 ± 0.18^b	*
	Day42	1 ± 0.0	1.10 ± 0.67	1.64 ± 0.85	0.87 ± 0.51	0.860.43	0.70.0.4	N.S
IL-10	Day7	1 ± 0.0^a	0.13 ± 0.07^b	0.26 ± 0.27^b	0.62 ± 0.21^a	0.40 ± 0.34^b	0.57 ± 0.35^b	*
	Day 21	1 ± 0.0^a	0.77 ± 0.19^a	0.43 ± 0.24^b	0.61 ± 0.18b	0.62 ± 0.16^b	0.64 ± 0.19^b	*
	Day42	1 ± 0.0	0.98 ± 0.24	0.98 ± 0.57	0.98 ± 0.88	0.80 ± 0.82	0.48 ± 0.14	N.S
Il-6	Day7	1 ± 0.0^a	0.45 ± 0.19^b	0.35 ± 0.25^b	0.55 ± 0.24^b	0.39 ± 0.22^b	0.38 ± 0.28^b	*
	Day 21	1 ± 0.0^b	0.50 ± 0.34^b	2.42 ± 0.79^a	0.89 ± 0.75^b	0.95 ± 0.87^b	1.50 ± 0.66^b	*
	Day42	1 ± 0.0	1.06 ± 0.60	0.73 ± 0.27	0.50 ± 0.32	0.57 ± 0.26	0.41 ± 0.31	N.S

^a,bData with the same letter in the same row are not significantly different (P ≤ 0.05).

N.S: no significant differences.

Conclusion

As these cytokines may be used to indicate inflammatory immune response (Rafter et al., 2007), the downregulated gene expression of several cytokines in birds fed treatments compared to the control suggests that these findings support the concept that dietary prebiotic, probiotic and synbiotic inclusion could enhance the immunity in the chicken by inhibiting the level of pathogenic bacteria in the gut; reducing the requirement to mount an inflammatory response. Examination of the microbial community is required to substantiate this hypothesis.

References

• Isolauri, E., et al., (2001). The American Journal of Clinical Nutrition, 73(2 Suppl).
   Google Scholar
• Mookiah, S., et al., (2014). Journal of the Science of Food and Agriculture, 94(2), 341–348.
   PubMed Web of Science ®Google Scholar
• Rafter et al., (2007). Animal Journal of Clinical Nutrition, 85(2), 488–496.
   PubMed Web of Science ®Google Scholar

Influence of naked neck gene and housing system on egg production and immune response of laying hens

M. Fathi, I. Al-Homidan, T. Ebeid and O. Abou-Emera

Qassim University, Buraidah, Al-Qassim, Saudi Arabia

CONTACT M. Fathi [email protected]

Application

There is a need to find hens adapted to the systems prevalent in the environment found in Saudi Arabia. Since 2012, the European Union has banned raising chickens in conventional cages. Alternative rearing systems for laying hens such as furnished cages, free range, littered floor or barn and organic production are allowed.

Introduction

In Saudi Arabia, all commercial table eggs are produced from flocks raised in fully controlled houses equipped with conventional battery cages. However, small poultry farmers and stakeholders still raised their native flocks in housing system similar to free range style. Native chickens segregating for naked neck gene have gained much attention due to possessing higher adaptability to prevailing environmental conditions, resistance to disease and a conserved gene pool (Fathi et al., 2013, 2017). Therefore, the aim of the present study was to evaluate the interaction between housing system and the naked neck gene in laying hens raised under high ambient temperature.

Materials and methods

Three different genotypes (NaNa, Nana and nana) of laying hens segregating for the naked neck gene were raised in either conventional wire cages or free range system during summer season. The average ambient temperature inside the house ranged from 39.1°C to 23.4°C. Egg production traits were recorded during an experimental period lasting 3 months. To examine cell-mediated immune response, 60 hens were used (10/genotype/housing system). Each hen was intradermally injected in the right wattle with 100 μg Phytohemagglutinin-P (PHAP) (Sigma Chemical Co., St. Louis, MO 63178) in 0.1 mL sterile saline. The thickness of resulting swelling was measured with a constant tension caliper before injection and at 24, 48 and 72 h after PHAP injection. The wattle swelling was calculated as the difference between its thickness before and after injection. Detection of antibodies against Newcastle disease virus (NDV) in serum of immunized chickens was performed by enzyme-linked immunosorbent assays (ELISA) using NDV antibody commercial test kit to determine humoral immunity (BioChek, Reeuwijk, the Netherlands).

Results

As shown in Table 1, a significant increase (P < 0.01) in productive traits was detected in naked neck laying hens (NaNa and Nana) compared to nana sibs. Laying hens kept in cages produced significantly heavier egg weights (P < 0.01) compared to those kept in free range systems. A significant improvement (P < 0.01) in cell mediated response was noticed in Nana genotype after 2h and 72 h after PHA-P injection compared with normal feathered genotype (nana). The homozygous naked neck (NaNa) was intermediate. There was no significant difference in humoral immune response due to either genotype or housing system. However, a numerical increase was found on naked neck hens raised in wire cages.

Table 1. Effect of naked neck gene and housing system on productive traits and immune response of laying hens

	Genotype (G)			HS			P-value
Item	NaNa	Nana	nana	C	FR	SEM	G	HS	G x HS
Hen day egg production%,	52.3^b	56.0^a	49.1^c	51.9	53.0	0.46	<0.01	0.18	0.46
Egg weight, g	49.6^a	49.9^a	48.9^b	49.9^a	49.0^b	0.09	<0.01	<0.01	<0.01
Broken eggs, %	2.4 ^b	2.6 ^b	3.9 ^a	3.2	2.5	0.27	0.05	0.20	0.95
CMI
24 h post injection	0.63^b	0.78^a	0.63^b	0.71	0.65	0.032	0.05	0.33	0.41
48 h post injection	0.49	0.61	0.47	0.55	0.50	0.028	0.08	0.35	0.49
72 h post injection	0.28^b	0.42^a	0.16^c	0.32	0.26	0.026	<0.01	0.14	0.35
Humoral immunity
NDV titre	5902.6	5935.8	5833.4	5967.8	5813.3	65.9	0.81	0.24	0.22

Means within rows with no common letters are significantly differed.

HS: housing system; C: cage; FR: free range; CMI: cell-mediated index.

Conclusion

In conclusion, these results indicate that the naked neck gene significantly improved egg production traits and cell-mediated immunity, particularly in laying hens raised in conventional cages under high ambient temperature.

References

• Fathi, M. M., Galal, A., El-Safty, S., & Mahrous, M. (2013). World’s Poultry Science Journal, 69, 813–832.
   Web of Science ®Google Scholar
• Fathi, M. M., Al-Homidan I., Motawei M. I., Abou-Emera O. K., & El-Zarei M. F. (2017). Poultry Science, 96, 530–536.
   PubMed Web of Science ®Google Scholar

Supporting gut health of high performing boilers in the presence of coccidiosis

D. Harrington^a, H. Hall^a, G. Mathis^b and W. Wakeman^a

^aAnpario Plc, Worksop, UK; ^bSouthern Poultry Research Inc, Athens, GA, USA

CONTACT D. Harrington [email protected]

Application

This trial was designed to evaluate a phytogenic ingredient in the diet of commercial broilers as an alternative to conventional anticoccidials.

Introduction

Coccidiosis is estimated to cost the global poultry industry over £2 billion annually (Williams, 1999). Anticoccidial medication or vaccination is the foundation of coccidiosis management, although increasing drug resistance and consumer concerns regarding antibiotics are driving alternative management practices. The performance of birds fed a commercial oregano essential oil (OEO) product standardised for thymol and carvacrol levels in the minimum ratio 1:38 (Orego-Stim, Anpario Plc, UK), was compared to birds fed either salinomycin, vaccinated with an anticoccidial vaccine or given both anticoccidial vaccine and OEO concurrently.

Materials and methods

A study was run at Southern Poultry Research Inc (USA). A total of 1760 Cobb 500 male chicks were randomly allocated to 4 treatments (8 pens/treatment, 55 birds/pen): (1) SAL: salinomycin, 60ppm in feed; (2) OS: OEO, 300g/t in feed; (3) VACC: Coccivac B52 (Merck Animal Health, USA) via hatchery spray at day-old and (4) VACC+OS: Coccivac via hatchery-spray at day-old and OEO, 300g/t in feed. All rations were corn-soy based and did not contain anticoccidial compounds with the exception of treatment 1 (SAL), which did. Diets were formulated to meet the bird’s requirements and feed and water were provided ad libitum. Birds were reared in floor pens on reused litter for 42 days. Performance (body weight gain [BWG] and FCR) were calculated for 0–42 days. On day 21, 5 birds/pen were transferred to cages. Forty coccidia-free birds that had been reared separately in cages from day-old (5 birds/cage) served as a positive challenge control (POS). Birds were dosed orally with a combination of Eimeria acervulina, E. maxima and E. tenella (15,000 oocysts/ml) in a 3 ml dose. On day 26, birds were euthanased and scored for coccidial lesions (LS) according to Johnson and Reid (1970). Data were analysed by ANOVA using Minitab (Minitab Inc.) and significance declared at P < 0.05. All procedures were conducted according to the prevailing national legislation on the use of animals in research.

Results

Birds fed SAL, OS or VACC + OS had significantly higher BWG than VACC alone (Figure 1). Similarly, FCR was significantly lower in SAL, OS and VACC + OS versus VACC (1.64, 1.67, 1.69 and 1.87, respectively). POS produced a LS of 3, confirming the challenge model was successful (Figure 2). All treatments had significantly lower (P < 0.05) LS than POS. SAL and OS had significantly higher (P < 0.05) LS than VACC and VACC + OS, while VACC + OS and OS LS did not differ significantly.

Figure 1. Weight gain (kg) 0–42 days.

Figure 2. Lesion scores 6 days following Eimeria challenge (d21).

Conclusion

Products based on oregano essential oil can provide a strategy to manage gut health in the presence of a coccidial challenge. Furthermore, the use of an oregano essential oil product concurrently with an anticoccidial vaccine (based on wild-type Eimeria strains) does not compromise vaccine efficacy.

References

• Johnson, J., & Reid, W. M. (1970). Experimental Parasitology, 28, 30–36.
   PubMed Web of Science ®Google Scholar
• Williams, R. B. (1999). The International Journal of Parasitology, 29, 1209–1299.
   PubMed Web of Science ®Google Scholar

Curcuma longa supplementation in broiler feed: effect on physiological responses and performance under a hot, humid, tropical climate

O. Oke, J. Daramola, A. Rahman and T. Lawal

Federal University of Agriculture, Abeokuta, Abeokuta, Nigeria

CONTACT O. Oke [email protected]

Application

Farmers can make use of turmeric rhizome powder to ameliorate the effect of heat stress on broiler chickens.

Introduction

Broiler production in tropical climates is encumbered by the adverse effects of heat stress (Farooq et al., 2005) but dietary manipulation such as addition of antioxidants may ameliorate this in some months in the year (Flachowsky, 2002). The phenolic compound, turmeric (Curcuma longa), has known antioxidant properties (Ammon et al., 1993) so this study investigated the influence of turmeric rhizome powder on physiological responses and performance under a tropical climate.

Materials and methods

Two hundred and forty Marshal day-old broiler chicks, having been granted permission by the College ethical committee, were randomly assigned to 4 dietary treatments having 4 replicates of 15 birds each in a complete randomized design. Broiler birds were fed maize-soybeans based basal diets and supplemented with 0, 4, 8 and 12 g of turmeric powder/Kg of diet for 8 weeks. Mash diets were formulated to meet NRC (1994) nutrient recommendations for the starter phase (0–4 weeks) and the finisher (4–8 weeks) feeding phase of the birds. Data were collected on feed intake and body weights weekly. Blood samples were collected from 8 birds per treatment at week 4 (starter phase) and week 8 (finisher phase) of the experiment for the determination of plasma 3,5,3ʹ-triiodothyronine (T₃), superoxide dismutase (SOD), malondialdehyde (MDA) following the methods of Tachibana et al. (2007), Misra and Fridovich (1972) and Tappel and Zalkin (1959), respectively. Rectal temperature of 4 birds per replicate were also taken. At 56 days of age, 8 birds from each treatment were slaughtered for the determination of relative organ weights.

Results

The results generally showed that turmeric at the dose of 8 g/kg was optimum for broiler birds under hot humid conditions (Table 1). The birds fed 4 g/kg diet had higher weights than those in the control group.

Table 1. Effect of different levels of turmeric rhizome powder on performance and physiological response of broiler chickens.

	Levels of turmeric rhizome (g/kg diets)
Performance Parameter	0	4	8	12	SEM	P value
Initial weight	729	730.50	728.75	733.50	1.525	0.7174
Final weight	1964^c	2169.75^b	2605^a	2268.78^b	66.590	0.0001
Feed intake	2893^b	2947^b	3372^a	3040.5^b	52.80	0.0001
Weight gain	1235^d	1434.5^c	1876.0^a	1643.5^b	63.044	0.0001
FCR	2.35^a	2.05^b	1.79^c	1.85^c	0.061	0.0001
Starter plasma SOD	116.0^b	126.0^a	132.5^a	128.0^a	1.854	0.0016
Finisher plasma SOD	125.3^c	127.3^bc	135.0^a	134.0^ab	1.303	0.0021
Starter Phase T3	1.16	1.41	1.53	1.62	0.072	0.1054
Finisher Phase T3	1.36^b	1.62^a	1.65^a	1.58^a	0.037	0.0067
Starter MDA	5.19^a	2.00^b	1.05^b	1.70^b	0.457	0.0001
Finisher MDA	4.23^a	1.65^b	0.34^c	1.92^b	0.376	0.0001

No common lettering indicates that there is a significant difference between treatments (P<0.05).

Conclusion

Turmeric rhizome powder improved the physiological response and performance of broiler chicken under hot humid tropical climate in a dose-dependent characteristic and the optimum supplementation rate of 8 g/kg of diet was recorded.

References

• Ammon, H., Safayhi, H., Mack, T., & Sabieraj, J. (1993). Journal of Ethnopharmacology, 38, 113–119.
   PubMed Web of Science ®Google Scholar
• Farooq, H. A. G., Khan, M. S., Khan, M. A., Rabbani, M., Pervez, A., & Khan, J. A. (2005) International Journal of Agriculture and Biology, 7, 744–746.
   Google Scholar
• Flachowsky, G., Engelman, D., Sunder, A., Halle, I., Sallmann, H. P. (2002). Food Research International, 35, 239–243.
   Web of Science ®Google Scholar
• Misra, H. P., & Fridovich, I. (1972). Journal of Biological Chemistry, 247, 3170–3175.
   PubMed Web of Science ®Google Scholar
• Tachibana, T., Oikawa, D., Takahashi, H., Boswell, T., & Furuse, M. (2007). Comparative Biochemistry Physiology – Part A, 147, 173–178.
   Web of Science ®Google Scholar
• Tappel, A. L., & Zalkin, H. (1959). Archives of Biochemistry and Biophysics, 80, 333–336.
   Google Scholar

The effect of calcareous marine algae in diets containing low levels of calcium on broiler performance, bone strength and meat quality parameters

M. E. E. Ball^a, D. Farrell^a and S. Taylor^b

^aAgri-Food and Biosciences Institute, Hillsborough, UK; ^bCeltic Sea Minerals, Cork, Ireland

CONTACT M. E. E. Ball [email protected]

Application

The use of calcareous marine algae (CMA) in low calcium (Ca) diets may have positive effects in terms of bone strength and meat quality parameters while maintaining performance equivalent to lower Ca diets.

Introduction

Evidence suggests that reducing Ca in broiler diets can improve growth performance, feed efficiency and phytase activity (Walk et al. 2012), but bone development can be impaired (McDonald et al. 1996). Calcareous marine algae (CMA) can improve bone development in rodents (Brennan et al. 2017). This experiment was devised to establish the opportunity to improve growth and feed efficiency in broilers by reducing the calcium content of the diet, but maintaining skeletal integrity by including CMA in a dose response manner as part of the calcium supply.

Materials and methods

This work was approved by the AFBI Animal Welfare Ethical Review Body. Broiler diets were formulated to be adequate in all nutrients according to Ross 308 recommendations, for the starter (1–14 d) grower (14–21 d) and finisher (21–35 d) periods. Phytase at 500 FTU/kg was included in all diets at the expense of Ca and P to provide 1.5 g/kg P and 1.6 g/kg Ca. The diets were wheat/soya bean meal based and balanced for energy and essential amino acids. Four treatments were produced to vary the level of Ca in the diets with two levels of CMA. Treatment 1 was the control and was formulated to contain 9.0, 8.0 and 7.0 g/kg Ca in the starter, grower and finisher diets, respectively. Treatments 2, 3 and 4 were formulated to contain lower levels of Ca; 8.0, 7.0 and 6.0 in the starter, grower and finisher diets. CMA was included in treatments 3 and 4 at 2 and 4 g/kg, respectively. Diets were offered to male Ross 308 birds, with 8 replicates of 10 birds per pen (reduced to 6 at 21 d) per treatment. Feed and water were offered ad libtium from 0 to 35 d. Birds were weighed at 7 d, 14 d, 21 d, 28 d and 35 d and liveweight gain (LWG), feed intake (FI) and feed conversion ratio (FCR) were calculated for the starter, grower, finisher and overall period. FI was adjusted to take account of wastage according to Ross 308 performance standards. Two birds per pen (16 per treatment) were killed locally at 35 d, hung for 24 h for and the left breast dissected for meat quality assessments (pHU, colour, Chroma, hue, drip loss, cooking loss, thaw loss). A further two birds per pen were killed, the left tibia dissected and bone width and breaking strength determined. Ileal digesta was also removed from these birds and analysed for dry mater (DM), energy and crude protein (CP) to determine apparent ileal digestibility by the indigestible marker method (titanium dioxide). Pen was taken as the experimental unit and the results were analysed by ANOVA.

Results

Overall LWG (0–35 d) was improved (P = 0.001) by reducing the Ca level in the diet but was not influenced by the use of CMA (Table 1). Adjusted feed efficiency (0–35 d) was not significantly improved by reducing the Ca level of the diet although there was a significant improvement over the grower stage (1.25 vs. 1.41, P = 0.047). Apparent ileal digestibility of DM, energy and CP were not significantly (P > 0.05) affected by experimental treatment. Bone width was significantly influenced by treatment (P = 0.039), being reduced when dietary Ca was reduced but then corrected with the inclusion of CMA in the low calcium diet in a dose responsive manner. There was no effect (P > 0.05) on bone strength (average 32.5 kgF). There was no significant effect (P > 0.05) on any meat quality parameter but drip loss and thaw loss were numerically reduced by the inclusion of CMA (Table 1).

Table 1. The effect of experimental treatment on broiler performance, drip loss and thaw loss.

	Control	Low Ca	Low Ca + CMA 2 kg	Low Ca + CMA 4 kg	SEM	P-value
Overall LWG (0–35 d) (g)	2195^a	2367^b	2407^b	2376^b	36.7	0.001
Overall FCR (0–35 d)	1.58	1.54	1.52	1.51	0.03	0.482
Bone width (mm)	7.43^a	7.28^a	7.50^ab	7.76^b	0.112	0.039
Drip loss (%)	1.84	1.92	1.70	1.81	0.213	0.912
Thaw loss (%)	8.96	8.94	8.18	8.16	0.399	0.307

^a,bSuperscripts indicate significant differences (P < 0.05).

Conclusion

Growth performance can be improved by restricting the calcium level in the diet but this compromised skeletal integrity as measured by bone width. Use of CMA in association with low dietary calcium had no effect on gain, numerically improved adjusted feed efficiency and significantly improved bone width in a dose responsive manner. These results and the potential to reduce drip loss and thaw loss should be confirmed by further experimentation.

Acknowledgements

The authors acknowledge funding from Celtic Sea Minerals (Cork) and Dr C Walk of ABVista for supply of phytase and help with diet formulation.

References

• Brennan, O., Sweeny, J., O’Meara, B. and O’Brien, F. J. (2017). Calcified Tissue International, 101, 445–455.
   PubMed Web of Science ®Google Scholar
• McDonald, P., Edwards, R. A., Greenhalgh, J. F. D., & Morgan, C. A. (1996). Animal Nutrition (5th ed., pp 102).
   Google Scholar
• Walk, C. L., Addo-Chidie, E. K., Bedford, M. R. and Adeola, O. (2012). Poultry Science 91: 2255–2263.
   PubMed Web of Science ®Google Scholar

A bird’s eye view of lighting in poultry housing – the science of poultry vision

D. L. Williams

University of Cambridge, Cambridge, UK

CONTACT D. L. Williams [email protected]

We like to think of ourselves as top of some evolutionary ladder don’t we? Humans are more advanced than other mammals, and certainly more than birds – this helps us rationalise the fact that we kill billons of chickens each year to eat. And vision-wise we seem to be on a good footing – we see in three different colours – red green and blue, apart from those with red-green colour blindness, that is, while all sub-primate mammals see only in two colours. But truth be told all birds are a good step above us in their visual perception. They can see in four colours; red, green blue and ultraviolet. Now quite what difference that means behaviourally to a bird is unclear apart from the fact that at dawn and dusk there is a greater level of UV than other elements of the electromagnetic spectrum so bird vision at these times is better than ours. Another key difference is that while we perceive a flickering light to be a constant illumination at a relatively low rate of flicker (the flicker fusion frequency [FFF]) birds still perceive a flickering at a significantly higher FFF. And while this difference is substantial at wavelengths in the visible spectrum (as far as humans are concerned), when we look at FFF in the UV range the value for birds is even higher, well above the flicker rate for the lighting normally available in broiler houses for instance. The question though is not primarily a physiological one but rather a welfare one – does a flickering illumination impact on a bird’s welfare as has been shown in humans experiencing migraines when working with computer screens where increasing the flicker rate of screen renewal has been shown to lessen headaches? Should we look at increasing the flicker rate of illumination in poultry housing? And how might we know if we had been successful in reducing deleterious effects on poultry? Having considered the chicken eye we should move to discussing recent developments in lighting technology. From an industry that depended on incandescent or fluorescent lighting we are now moving to light emitting diodes. These are much more energy efficient and thus cheaper but also can be tuned to specific light wavelength. We know that behaviourally red light increases aggression and feather pecking and that green lighting yields calmer behaviour. Being able to define much more precisely exactly what lighting regime we are providing for poultry will allow a more welfare-friendly environment to be created, especially important given how central vision is to these birds.

Going ‘cage free’ by 2025 – welfare consequences for laying hens

V. Sandilands

SRUC, Ayr, UK

CONTACT V. Sandilands [email protected]

The commitment of the UK’s (remaining) major supermarkets to only provide eggs from non-caged birds from 2025 will have a significant impact on the lives of millions of hens. Another paper (Gittins 2018, this volume) has detailed estimates of bird numbers going to alternative systems, but what does that mean for hen welfare? This paper considers welfare consequences for hens moving into barn, free-range or organic housing, using the Five Freedoms as a framework.

Thirst, hunger and malnutrition

In all systems, these are generally prevented, as a thirsty, hungry or malnourished hen will not lay many eggs! However, competition can still occur. Linear feed troughs must provide 10 cm/hen or more, but the width of a standard brown hen has been estimated at as much as 18 cm so not all birds can feed together. Subordinate birds are more likely to be displaced from feed troughs than dominant birds and displacements are greater at low feed space allowances (Widowski et al., 2017).

Pain, injury and disease

Non-cage systems have a greater chance of causing pain, injury and disease compared to cage systems. Keel bone damage is higher in non-cage systems than cages, which is likely to be painful, and has been associated with perches and the height to which birds can ascend to. However, improved perch design reduces the chance of injury, and the provision of ramps in multi-tier systems to allow birds to execute controlled descents has been shown to reduce falls and collisions (Stratmann et al., 2015). Most barn and free-range hens are routinely beak trimmed by infra-red, but organic flocks are not. This method causes short-term pain in laying chicks; however, the benefit is that the dulled beak tip helps reduce damage caused by injurious pecking, should it occur. Mortality rates are generally higher in non-cage systems than in enriched cages. Disease risks are higher where birds are housed on the floor compared to enriched cages where birds are separated from their faeces. Where birds have access to outdoor runs, there is greater exposure to bacterial, viral, parasitic or fungal pathogens, including avian influenza, Newcastle’s disease and mycoplasma. Red mite infestations are also reported to be worse in free range systems. Air quality is typically lower in some non-cage systems where manure is not removed but collects beneath slats, and/or because the house is naturally ventilated, causing high ammonia levels. This can lead to respiratory damage and greater risk of respiratory diseases.

Thermal and physical discomfort

There are greater thermal choices in non-cage systems, because birds can move around a greater footprint but also vertically. Especially where outdoor access is given, birds can choose to move in and out of different temperature zones, and other climate effects (wind, rain, sun, etc.). All systems provide nest boxes and perches, although interpretation around what these look like vary, but non-cage systems have the advantage over enriched cages of providing litter, which contributes to bird comfort, as long as it is dry and friable.

Fear and distress

A more diverse environment, as is found with non-cage systems compared to cages, can make hens less reactive to novelty and thus less fearful, however birds in non-cage housing systems are more likely to smother when they do show a fear reaction.

Performing natural behaviours

Non-cage systems allow hens to express a greater suite of motivated behaviours than enriched cages: they provide more space per hen, and free range and organic systems also provide outdoor runs. Perches can provide a refuge for hens seeking to escape unwanted attention of feather peckers or dominant hens, while also allowing perching and roosting behaviour, especially at night. Perches increase leg bone strength but the proportion of birds with keel bone damage increases in non-cage housing and with the height that birds can ascend to, suggesting that the freedom of movement comes with risk of injury. Feather pecking is a problem in all types of hen housing systems, but tends to be worse in non-cage systems. Feather pecking is closely related to foraging motivation, and studies show that if hens are provided with, and use, outdoor runs this can reduce the risk of feather pecking and cannibalism. Hens are highly motivated to show nesting behaviour. All systems in the UK provide nest boxes of some description, allowing birds to seek a secluded area in which to lay their eggs. Nest boxes are particularly crowded during peak laying times, and favoured nest boxes in non-cage housing (where hens have a choice of multiple nest boxes) can lead to smothering. Dustbathing behaviour can be expressed in non-cage housing, either in the floor litter or in dirt on the outdoor run. Dustbathing serves to remove stale preen oil from feathers, which keeps the plumulaceous (downy) part of feathers fluffy and thus aids with insulation.

In summary, non-cage housing comes with greater risks to hen welfare, but the scope for greater behavioural freedom is higher also. Decisions on how risks are balanced against bird preferences are somewhat subjective: which bird has the life worth living? Implementing suitable management strategies can reduce risks associated with non-cage housing, such as injurious pecking (Lambton et al. 2013). Therefore, while risks are higher there is also great scope for improvement.

Acknowledgements

Thank you to WPSA UK programme committee for inviting this paper.

References

• Lambton, S. L., et al. (2013). Veterinary Record, 172.
   Google Scholar
• Stratmann, A., et al. (2015). Applied Animal Behaviour Science, 165, 112–123.
   Web of Science ®Google Scholar
• Widowski, T., et al. (2017). Poultry Science, 96, 3816–3823.
   Google Scholar

Growing site influences wheat apparent metabolisable energy value for broiler chickens

R. Azhar^a, S. P. Rose^a, S. C. Mansbridge^b, M. R. Bedford^b and V. R. Pirgozliev^a

^aNational Institute of Poultry Husbandry, Harper Adams University, Newport, Shropshire, UK; ^bAB Vista, Marlborough, UK

CONTACT R. Azhar [email protected]

Application

Consideration should be given to the non-starch polysaccharides and metabolisable energy content of wheat when formulating rations containing xylanase enzymes for broiler chickens.

Introduction

Wheat is the most used raw material in UK poultry feed and often the only cereal in broiler grower and finisher diets. The nutritional value of wheat and variations in feeding quality have significant commercial importance as it influences efficiency and rate of broiler chicken growth. Its nutritive value has to be considered at the ration formulation stage. Wheat is primarily used in broiler feeds for its available energy, but there is considerable variation in the apparent metabolisable energy (AME) of different wheat samples (Ball et al., 2013). The aim of this study was to understand the differences in AME of modern UK wheat cultivars and possible influence of growing site. In addition, the efficacy of xylanase supplementation on AME of wheat was also evaluated.

Materials and methods

All procedures were approved by the Harper Adams University Research Ethics Committee. Three current UK wheat cultivars: Lili (92 g/kg total non-starch polysaccharides (tNSP) and 72 g/kg insoluble (insNSP) mean values), Barrel (96 g/kg tNSP and 74 g/kg insNSP), Kerrin (89 g/kg tNSP and 65 g/kg insNSP) from three growing sites: Lincolnshire, Cambridgeshire and Yorkshire (nine samples) were used in this study. Nine iso-nitrogenous diets were formulated all of which included the wheat sample at 670 and 330 g/kg of a balancer (Azhar et al., 2017). An extra diet containing 470 g/kg of wheat (Barrel from Lincolnshire) was used to determine AME in the basal diet. The diets were then split in two, and half of the diets were supplemented with xylanase at 16000 BXU/kg of diet (AB Vista, Marlborough, UK), resulting in 20 diets in total. All diets were pelleted by a laboratory pelleter (KAHL GmbH & Co. KG, Hamburg, Germany). A total of 960 male Ross 308 broilers were randomly allocated to 120 raised floor pens (8 birds per pen). Each diet was replicated 6 times, in a randomised complete block factorial design and fed ad libitum from 7 to 21 d age. Excreta were quantitatively collected and feed intake was recorded for the last three days for AME determination. Data were statistically analysed by ANOVA using a 3 × 3 × 2 factorial arrangement of treatments. The main effects were the wheat cultivar, the growing site and the xylanase (with and without). In all instances, differences were reported as significant at P < 0.05. When a significant F test was detected, means were separated using the Duncan’s multiple range test. Tendencies toward significance (0.05 < P < 0.1) were also reported.

Results

There was a wheat cultivar × xylanase interaction (P = 0.01), as supplementary xylanase improved AME of Lili and Barrel, but not of Kerrin (Table 1). Wheat samples cultivated at Cambridgeshire had higher AME, followed by wheat samples from Lincolnshire and Yorkshire (P < 0.001). While no significant interaction was observed between growing site and enzyme, there was an indication this should be investigated further (P = 0.06).

Table 1. Effect of wheat variety, growing site and xylanase supplementation on broiler AME (MJ/kg DM).

		Xylanase
		−	+	Mean AME	P value	SEM^1
	Lili	13.96^a	14.69^cd	14.32
Cultivar	Barrel	14.09ab	14.82^d	14.46	0.482	0.081
	Kerrin	14.38^bc	14.49^cd	14.43
	Lincolnshire	14.06	14.73	14.40^b
Site	Cambridgeshire	14.43	15.12	14.77^c	<0.001	0.081
	Yorkshire	13.94	14.15	14.04^a
Xylanase		14.14	14.67	14.40	<0.001	0.067
Cultivar × Xylanase					0.011	0.115
Site × Xylanase					0.063	0.115

¹Pooled effective standard error of the mean.

No common lettering indicates that there is a significant difference between treatments (P<0.05).

Conclusion

Supplementary xylanase improved the AME value of the cultivars with lower AME (Lilli and Barrel) but showed little improvement to high AME wheat (Kerrin). Cultivar Kerrin had a lower insNSP content suggesting that there was less substrate for enzyme activity. Differences in the AME of wheat from different sites indicate that more information on growing conditions, e.g. agronomy, solar radiation, soil type and rainfall is necessary to explain the results.

References

• Azhar, M. R., Rose, S. P., Mackenzie, A. M., Bedford, M. and Pirgozliev, V. (2017). Proceeding of World Poultry Science Association (UK).
   Google Scholar
• Ball, M. E., Owens, B. and McCracken, K. J. (2013). Asian-Australasian Journal of Animal Sciences, 26, 97–107.
   PubMed Web of Science ®Google Scholar

A method to increase the energy and nitrogen availability of rapeseed supplemented diets for broilers

E. Watts^a, V. R. Pirgozliev^a, S. P. Rose^a, A. Mackenzie^a and L. Bernard^b

^aHarper Adams University, Shropshire, UK; ^bDanisco Animal Nutrition, Wiltshire, UK

CONTACT E. Watts [email protected]

Application

Rapeseed meal produced by supercritical CO₂ extraction may be a superior energy and nitrogen source than hexane-extracted, desolventized and toasted rapeseed meal for broilers. Supplementation with dietary protease offers an effective method to further improve the digestibility of the diet.

Introduction

Rapeseed meal (RSM), a by-product of the rapeseed oil recovery process offers an alternative protein source to soybean meal (Khajali & Slominski, 2012). Prepressed hexane extraction (HxEx) is the most widely used method of oil recovery. However, during the final step, desolventizing/toasting (DT) heat damage can be incurred by the protein fraction and this may reduce the metabolizable energy (ME) content of the meal for broilers (Newkirk et al., 2003). Supercritical carbon dioxide extraction (scCO2) offers an alternative, industrially viable technology for oil recovery. The non-toxic properties of CO₂ eliminate the need for DT and thus, exposing the meal to deleterious heat treatments (Martin et al., 2015). This study evaluated the effect of rapeseed cultivar and method of oil recovery on the nitrogen corrected apparent ME (AMEn), and the coefficient of nitrogen retention (NR) in broilers. To potentially help negate the effects of processing and to enhance the utilisation of RSM, half of the diets were supplemented with endogenous protease derived from Bacillus subtilis (Danisco Animal Nutrition, Marlborough UK).

Materials and methods

All animal procedures were approved by the Harper Adams ethics committee. Three cultivars of UK-grown OSR were processed by scCO₂ and HxEx (processing temperatures 55°C and 55–108°C, respectively). All samples were prepressed but only the HxEx RSM underwent DT. In total 14 diets were mixed (12 RSM diets and 2 reference diets half with/without enzyme, 4000 units per kg). The RSM diets were prepared by supplementing the reference diet with 20% of the respective RSM products following adjustment to 880 g/kg dry matter (by adding water) and 60 g/kg oil content (by adding rapeseed oil). Male Ross 308 broilers (490) were reared in a common floor pen from 0 to 13 d age. Feed and water were provided ad libitum. At 13 d age birds were transferred to 98 raised-floor pens (5 birds per pen) located in an environment-controlled room. Experimental diets were randomly allocated to 7 replicate pens. Excreta were collected from 17 to 21 d age and feed intake was recorded. The total collection method was used to calculate AME, AMEn and NR. A randomized complete block ANOVA (3 × 2 × 2 factorial design) was used to investigate the main treatment factors (cultivar, processing and protease) on the AMEn and NR (P < 0.05).

Results

The results (Table 1) showed no significant main effects of cultivar (P > 0.05) and there were no interactions between the main treatment factors (P > 0.05). There was a significant effect of processing and protease (P < 0.05). The AMEn and NR of RSM scCO₂ diets were significantly greater than those of the HxEx diets. Protease supplementation significantly increased the AMEn and NR of the diets independent of processing method.

Table 1. The effect of cultivar, processing and protease on AME, AMEn and NR (DM basis) of RSM supplemented diets.

		AME MJ/kg DM	AMEn MJ/kg DM	NR
Cultivar	Cabernet	12.89	12.00	0.606
	Elgar	13.03	12.13	0.604
	Quartz	12.86	11.95	0.599
	SEM	0.08	0.08	0.004
Protease	Plus	13.04	12.13	0.610
	None	12.81	11.92	0.596
	SEM	0.07	0.07	0.003
Processing	scCO2	13.04	12.13	0.611
	HxEx	12.81	11.92	0.596
	SEM	0.07	0.07	0.003
P-values	Cultivar	0.328	0.282	0.474
	Protease	0.027	0.035	0.007
	Processing	0.018	0.022	0.002

Conclusion

Exposure of RSM to excessive heat treatment during DT may reduce the energy and nitrogen availability of RSM for broilers, perhaps due to a reduction in the digestibility of the protein fraction and of other nutrients. These effects may be overcome by employing milder oil recovery techniques such as scCO₂ and through dietary protease supplementation.

References

• Khajali, F. and Slominski, B. A. (2012). Poultry Science, 91(10), 2564–2575.
   PubMed Web of Science ®Google Scholar
• Martin, L., Skinner, C. and Marriott, R. J. (2015). The Journal of Supercritical Fluids, 105, 55–59.
   Web of Science ®Google Scholar
• Newkirk, R. W., Classen, H. L., and Edney, M. J. (2003). Animal Feed Science and Technology, 104, 111–119.
   Web of Science ®Google Scholar

Evaluating the effects of low crude protein diets on growth performance, meat quality, litter moisture, nitrogen excretion and environmental impacts in finishing broilers

B. Méda^a, P. Belloir^a, W. Lambert^b, E. Corrent^b, H. Juin^c, S. Tesseraud^a and M. Lessire^a

^aURA, INRA, Nouzilly, France; ^bAjinomoto Eurolysine, Paris, France; ^cEASM, INRA, Saint Pierre d’Amilly, France

CONTACT W. Lambert [email protected]

Application

Despite the strong belief that dietary crude protein (CP) reduction is a challenge in fast-growing modern broilers, the present data suggest that the limit in reducing CP has not been reached yet and that further improvements in terms of sustainable chicken meat production can be achieved.

Introduction

Increasing concern about European protein dependency, imported GMO soybean and environmental impact of meat consumption raise the interest in feeding lower protein levels to livestock. The aim of this study was to investigate the effects of decreasing dietary CP levels while controlling indispensable amino acid (AA) levels in broiler finishing diets on growth performance, meat quality, litter moisture, nitrogen excretion and environmental impacts assessed by Life Cycle Analysis (LCA).

Materials and methods

Experimental design, diet composition, growth performance evaluation and meat quality assessment are described in Belloir et al. (2017; Experiment 2). After being fed a common starter and grower, a total of 912 Ross PM3 male broilers were randomly distributed at 21 d into 3 treatments (8 pens per treatment, 38 broilers per pen) differing in dietary CP content (19, 17.5 and 16%) and fed ad libitum until 35 d. Environmental LCA impacts (climate change, acidification, eutrophication and non-renewable energy use) of feedstuffs were taken from the ECOALIM database (Wilfart et al., 2016). LCA was carried out in order to evaluate the environmental impacts of one ton of finishing diet and one ton of broiler (live weight), at feed mill and farm gates, respectively, for broilers fed with diets containing either 19% or 16% CP. The chosen scenario was the production of broilers in Pays-de-la-Loire region with a distance feed mill – farm of 50 km and hatchery – farm of 200 km. One-way ANOVA was performed using the GLM procedure of SAS. Experimental procedures and animal care were carried out according to current French legislation and under Authorizations 004601 and 006865.

Results

When reducing dietary CP from 19% to 16%, no significant effect could be observed on growth performance or meat quality parameters. Litter moisture and nitrogen excretion were linearly reduced when lowering dietary CP. Based on these results, a life-cycle analysis was carried out to compare the environmental impact of 1 kg of feed and 1 kg of broiler BW with the scenario at 19% or 16% CP. Results of LCA of one ton of finishing diet and one ton of broiler (live weight), at feed mill and farm gates, respectively, are shown in Table 1 and expressed in percentage of the 19% dietary CP treatment. Dietary CP reduction from 19% to 16% decreased climate change, eutrophication and energy use impacts. For acidification, the impact per metric ton increased due to the higher incorporation rate of corn, replacing soybean meal. At farm gate, all impacts were reduced when broilers were fed 16% CP. Acidification was also positively affected as the largest part of the impact at the farm gate comes from manure emissions (NH₃), which were lower due to the lover nitrogen excretion and volatilization shown by Belloir et al. (2017).

Table 1. Environmental impacts of broilers fed a 16% CP diet relative to a 19% CP diet at both feed mill and farm gate (%).

	Feed mill gate (ton of finishing diet)		Farm gate (ton of broiler live weight)
Impact	19% CP	16% CP	19% CP	16% CP
Climate change	100	86	100	92
Eutrophication	100	94	100	93
Acidification	100	104	100	95
Non-renewable energy use	100	99	100	99

Conclusion

Dietary CP reduction down to 16% in finishing broilers does not affect performance or meat quality traits, when using an adapted amino acid profile. Such a feeding strategy could improve the sustainability of broiler production with lower environmental impacts associated with the reduction of soybean meal use and nitrogen emissions. Results also suggest that LCA is more relevant when carried out at farm gate compared to feed mill gate, thus considering all impacts of the production chain (feed production, livestock and manure).

Acknowledgement

This research was supported in part by a grant from Ajinomoto Eurolysine, France.

References

• Belloir, P., Méda, B., Lambert, W., Corrent, E., Juin, H., Lessire, M., & Tesseraud, S. (2017). Animal, 11, 1881–1889.
   Google Scholar
• Wilfart, A., Espagnol, S., Dauguet, S., Tailleur, A., Gac, A., & Garcia-Launay, F. (2016). PLoS One, 11(12), 1–17.
   Google Scholar

Xylanase effect on growth partly explained by effect on pre-caecal flow of carbohydrate fractions in broilers

A. Craig^a, M. Bedford^b, P. Hastie^c, F. Khattak^a and O. Olukosi^a

^aSRUC, Edinburgh, UK; ^bAB Vista, Marlborough, UK; ^cGlasgow University, Glasgow, UK

CONTACT A. Craig [email protected]

Application

Xylanase supplementation generates prebiotic oligosaccharides in-situ which may have similar effects to the direct supplementation of dietary prebiotics. This provides another paradigm for the use of carbohydrases in broiler diets.

Introduction

The positive effect of xylanase on the growth performance of broilers is well established (Hajati et al., 2009). In the process of non-starch polysaccharide (NSP) hydrolysis xylanase potentially generates prebiotic oligosaccharides referred to as xylo-oligosaccharides (XOS) (Olukosi et al., 2015) which can have the same effect of dietary supplementation of prebiotics. The aim of this study was to investigate the affect of supplementation of xylanase or XOS on growth performance and flow of oligosaccharides from NSP hydrolysis in the ileal digesta of broilers.

Materials and methods

A 28-d trial involving 500 Ross 308 broilers was carried out. The experiment followed a randomised complete block design and treatments were arranged into a 2 × 2 plus 1 factorial. There were two additive types (AT: xylanase or XOS) and two inclusion levels (IL) of each (low or high) plus one control (no additive). The low and high levels for xylanase were 16,000 or 32,000 U/kg, respectively, whereas for XOS the levels were 0.025% or 0.1%, respectively. The control diet was deficient in energy and protein and contained 11.56 MJ/kg DM of ME and 200 g/kg DM of protein. This experiment was subject to ethical review by SRUC’s Animal Experiment Committee. Birds and feed were weighed on days, 0 and 28. Ileal digesta were collected on day 28 for NSP analysis. Carbohydrate flow is the measurement of free sugars. An increase in flow indicates a greater concentration of that specific carbohydrate in the ileal digesta and may suggest better digestibility of fibre. It was calculated using the methods described by Beeson (2017). The data on growth performance and pre-caecal flow of soluble NSP were analysed using the general ANOVA function of Genstat. In Table 1, contrast 1 refers to comparison of the control with the four treatments to investigate the effect of additive inclusion and were analysed as a one way ANOVA. Significance was declared at P ≤ 0.05.

Table 1. Growth performance and pre-caecal flow of selected soluble carbohydrate fractions (g/100g ileal digesta) in response to supplementation of xylanase or prebiotic xylose oligosaccharide.

	Treatments						P values
	Control	XYL16	XYL32	XOS0.025%	XOS0.1%	SEM	Cont 1	AT	IL	AT × IL
WG (g)	1313	1295	1320	1217	1306	29.202	NS	NS	NS	NS
FI (g)	2954	2707	2547	2537	2605	86.161	<0.001	NS	NS	NS
FCR	2.260	2.100	1.930	2.030	2.000	0.078	0.009	NS	NS	NS
Fructose flow	0.046	0.048^a	0.069^b	0.068^b	0.057^ab	0.007	0.083	NS	NS	0.032
Xylose flow	0.948	0.898	1.143	1.284	1.216	0.115	0.081	NS	NS	NS
Galactose flow	0.398	0.463	0.607	0.507	0.556	0.085	0.030	NS	NS	NS

^abMeans within a row but with different superscripts are significantly different (P < 0.05).

XYL16 and XYL32 - xylanase 16,000 or 32,000 U/kg; Cont. 1: contrast 1; AI: additive inclusion; AT: additive type; IL: inclusion level; WG: weight gain; FI: feed intake; FCR: feed conversion ratio; SEM: standard error of the means; NS: not significant.

Results

Table 1 shows the effect of xylanase or XOS supplementation on growth performance and pre-caecal NSP flow. Birds on the control diet had greater feed intake and feed conversion ratio (FCR) (P < 0.05) but lower galactose flow (P < 0.05) compared with the other treatments. Galactose flow was significantly (P < 0.05) lower in the control treatment compared with birds receiving XOS or xylanase supplemented diets. There were no significant main effects of AT or IL on growth performance or oligosaccharide flow. There was AT × IL interaction for pre-caecal fructose flow. Fructose flow significantly (P < 0.05) increased when xylanase supplementation was increased from 16,000 to 32,000 U/kg however there was no significant difference in fructose at the two XOS supplementation levels.

Conclusion

Xylanase and XOS had positive effects on FCR and increased the pre-caecal flow of carbohydrate fractions from NSP hydrolysis in the ileal digesta of broilers. These carbohydrate fractions can potentially act like prebiotics in the digestive tract of broiler chickens thus helping to promote gut health, growth performance and nutrient utilisation.

Acknowledgements

Allison Craig is a recipient of BBSRC-iCASE studentship.

References

• Beeson, L. A. (2017). (PhD Thesis). Glasgow University.
   Google Scholar
• Hajati, H, Rezaei, M, & Sayyahzacheh, H. (2009). International Journal of Poultry Science, 8, 1199–1205.
   Google Scholar
• Olukosi, O. A., Beeson, L. A., Englyst, K, & Romero, L. F. (2015). Poultry Science, 94, 2662–2669.
   PubMed Web of Science ®Google Scholar

Analysis of insulin-like growth factor 1 gene in Nigerian indigenous and Arbor Acre chickens

M. Wheto^a, O. O. Ismaila^a, A. S. Adenaike^a, M. A. Adeleke^b, S. O. Peters^c, C. O. N. Ikeobi^a and O. A. Adebambo^a

^aFederal University of Agriculture, Abeokura, Nigeria; ^bDiscipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, South Africa; ^bDepartment of Animal Science, Berry College, Mount Berry, Georgia, USA

CONTACT M. Wheto [email protected]

Application

Due to high demands of animal protein, the production costs of the poultry industry and the low productivity in Nigeria indigenous chicken, it is imperative to study the genetic variations that exist between the Nigerian indigenous chickens and their exotic counterparts and then utilize the variations for genetic improvement through marker assisted selection for better growth and development in Nigerian indigenous chicken.

Introduction

Insulin-like growth factor 1 (IGF-1) is a candidate gene for growth, body composition, metabolism, skeletal characteristics, growth of adipose tissue and fat deposition in chickens (Li et al., 2008; Zhou et al., 2005). The polymorphism in 5ʹ untranslated region of the chicken IGF-1 gene is significantly associated with lower egg weights and higher egg shell weights. Nigerian indigenous chickens constitute about 80% of the 166 million poultry birds in Nigeria (FAO, 2007). The Nigerian indigenous chicken exhibits diversity in morphological characteristics and consist of various unimproved sub-populations of heterogeneous characteristics, not yet classified into breeds

Materials and methods

One millilitre of blood sample was collected from the experimental birds from which genomic DNA was extracted using Qiagen DNA extraction kits and the target fragment of IGF-1 gene (5ʹUTR) was amplified using polymerase chain reaction (PCR). PCR was carried out using the primers reported by Zhou et al. (2005). The PCR amplicon involving 5ʹuntranslated region was sequenced and the nucleotide sequences generated were edited and aligned using CodonCode Aligner. The sequences were analysed to identify polymorphisms, their genetic diversities and evolutionary relationships among three strains of Nigerian indigenous chickens (Frizzle Feathered, Normal Feathered and Naked Neck and the Arbor Acre broiler chicken). Diversity analysis was done using DnaSP while MEGA6 software was used to plot phylogenetic tree using maximum likelihood method.

Results

A total of 19 single nucleotide polymorphisms (SNPs) were detected from 560 bp portions of the 5ʹUTR among the 4 chicken populations studied with none detected in the Frizzle Feathered chicken. The Naked Neck chicken had the highest number of SNPs (13), haplotypes (6), haplotype diversity (0.778), nucleotide diversity (0.00487), average number of nucleotide differences (2.725), and highest number of polymorphic (segregating) sites (13), parsimony informative site (5) and singleton variable site (8). The Naked Neck chicken therefore had the highest rate of mutation and degree of allelic variation compared to the other strains of chickens used in this study. The phylogenetic tree showed that small genetic differentiation exists among the chicken populations studied. Some of the SNPs are newly discovered hence, association between these alleles (SNPs) and productive traits in our native chickens should also be estimated for confirmation of their effects in further studies (Table 1).

Table 1. Genetic characteristics.

Genotype	S	h	Hd	K	Pi	SP	PIP
Arbor acre	3	3	0.324	0.838	0.00150	0	3
Naked neck	13	6	0.778	2.725	0.00487	8	5
Normal feathered	2	3	0.556	0.596	0.00107	1	1
Frizzled feathered	0	1	0	0	0	0	0
Total	14	9	0.629	1.420	0.00254	9	5

h: number of haplotype; S: number of polymorphic (segregating) site; Hd: haplotype diversity, k: average number of nucleotide differences; Pi: nucleotide diversity; SP: singleton variable site, PIP: parsimony informative sites.

Conclusion

Analysis of the 5ʹ UTR IGF-1 gene sequence in the Nigerian indigenous chicken and Arbor Acre chicken showed the existence of polymorphism except in the Frizzle Feathered chicken. The level of polymorphism varied according to genotype. The Naked Neck chicken had the highest number of polymorphism while Frizzled Feather chicken had none. Naked Neck had the highest level of diversity in all the genetic parameters measured. The phylogenetic tree showed that small genetic differentiation exists among the chicken populations studied.

Acknowledgements

We want to acknowledge the PEARL Project of the Bill and Melinda Gates foundation for the development and improvement of indigenous chicken in Nigeria for poverty alleviation.

References

• FAO. (2007). The Journal of the Scientific Agricultural Food Technology and Environment, 1, 1–3
   Google Scholar
• Li H., Zhu W., Chen K., Wu X., Tang Q., & Gao Y. (2008). Turkish Journal of Veterinary and Animal Science, 32(4), 281–285.
   Google Scholar
• Zhou, H., Mitchell, A. D., McMurtry, J. P., Ashwell, C. M., & Lamont, S. J. (2005). Poultry Science, 84, 212–219.
   PubMed Web of Science ®Google Scholar

Effects of diets supplemented with different zinc sources on performance, egg quality, parameters of bones and zinc retention in laying hens

F. Shariatmadari, M. Abedini, H. Ahmadi and M. A. K. Torshizi

Tarbiat Modares University, Tehran, Iran

CONTACT F. Shariatmadari [email protected]

Application

This experiment was conducted to investigate the effect of feed supplemented with different zinc (Zn) sources on performance, egg quality, parameters of bones and Zn retention in laying hens. It is hypothesised that different zinc sources affect layer performance differently.

Introduction

Zinc is an essential element for many metabolic processes in living organisms and thus should be supplied in poultry diets. The main sources of minerals used in animal feeds are inorganic mineral salts which have low bioavailability. On the other hand, organic mineral sources such as zinc proteinate have been used increasingly in recent years due to their higher bioavailability; however, their use in animal feed is limited due its high cost (Zhao et al., 2014). With the introduction and advancement of nano technology, usage of nano particles (minerals) has gathered attention (Gao & Matsui, 2005). Recently, researchers have found that nano-silver, nano-selenium and ZnO-nano-particles have a positive effect on broiler performance (Ahmadi et al., 2013).

Materials and methods

A total of 192 (White HyLine W36) laying hens at 52 weeks of age were distributed in a completely randomised experimental design with 4 treatments, 5 replicates and 10 birds for each experimental unit. Fed over a 12-week duration, the 4 dietary treatments included the corn–soybean meal-based diet (without supplementary Zn addition, containing 21.4 mg/kg Zn) and the basal diet supplemented with 80 mg/kg of either Zn-oxide, Zn-methionine or Zn-nano-oxide (containing 101.4 mg/kg Zn). The recommended zinc level for laying bird is 90 mg/kg. The feeding programme, lighting schedule and housing temperature was as per HyLine instruction. At the end of the experiment, performance, egg production, egg quality and zinc content of tibia, egg, plasma and liver were measured and evaluated accordingly. Treatment means were compared using the Duncan’s Multiple Range Test, and values were considered statistically different at P < 0.05. The Animal Ethics Committee of the Tarbiat Modares University approved the experiment.

Results

The results showed that there were significant effects from Zn supplementation on egg mass (egg weight and egg production), feed conversion ratio, shell characteristics (strength and weight) and zinc content of tibia, egg and liver (P < 0.05). However, feed intake, live body weight gain and egg yolk and albumin weights and characteristics such as yolk colour and Haugh unit (not presented here) were not influenced by dietary treatments. Overall Zn supplementation improved shell strength and increased shell weight (P < 0.05). Dietary Zn-nano-oxide supplementation increased shell strength compared to the control and Zn-oxide treatments (P < 0.05). At the end of the experiment, the morphometric characteristics of the tibia, such as tibia dry weight and length, were not affected by dietary treatments but ash weight was significantly higher in groups with Zn supplementation (P < 0.05). The Zn deposition in tibia and eggs were significantly higher in birds fed Zn supplemented diets (P < 0.01). Plasma Zn status was not influenced by treatment (Table 1).

Table 1. Effects of different sources of Zn on performance, egg quality and retention in laying hens.

Treatment	Egg mass (g)	FCR (feed/EM)	Shell strength (kg)	Shell weight (g)	Egg Zn (µg/g)	Tibia Zn (µg/g)	Plasma Zn (mg/L)	Liver Zn(µg/g)
Control	48.31^b	2.15^a	3.27^c	5.62^b	8.19^c	231.9^d	1.39	102.9^c
Zn-oxide	49.63^b	2.12^ab	3.46^b	5.85^ab	12.46^b	253.8^c	1.43	138.9^b
Zn-methionine	52.67^a	2.02^b	3.53^ab	5.96^a	13.54^a	267.5^b	1.48	155.1^a
Zn-nano-oxide	52.81^a	2.01^b	3.72^a	5.94^a	14.13^a	274.3^a	1.47	159.5^a
SEM	0.56	0.02	0.04	0.12	0.44	2.8	0.01	4.07
P-value	0.001	0.03	0.001	0.02	<0.001	<0.0001	0.07	<0.0001

^a,b,cMean values within a column with no common superscript differ significantly (P ≤ 0.05).

SEM: standard error of means; EM: egg mass.

No common lettering indicates that there is a significant difference between treatments (P<0.05).

Conclusion

In conclusion, this study has shown that the supplementation of diets with Zn-nano-oxide or Zn-methionine can have a similar impact on improving the performance of laying hens, and could be a more suitable source than Zn-oxide in poultry diets.

References

• Ahmadi, F., Khah, M. M., Javid, S, & Akradi, A. (2013). International Journal of Bioscience, 3, 95–100.
   Google Scholar
• Gao, X., & Matsui, H. (2005). Advance Materials, 17, 2037–2050.
   PubMed Web of Science ®Google Scholar
• Zhao, C. Y., Tan, X. Y., Xiao, X. S., Qiu, J. Q., & Pan, Z. X. (2014). Biological Trace Element Research, 160, 361–367.
   PubMed Web of Science ®Google Scholar

Effects of diets supplemented with different zinc sources on performance, egg quality, parameters of bones and zinc retention in laying hens at late phase of production

F. Shariatmadari, M. Abedini and H. Ahmadi

Tarbiat Modares University, Tehran, Iran

CONTACT F. Shariatmadari [email protected]

Application

This experiment was conducted to investigate the effect of feed supplemented with different Zn sources on performance, egg quality, parameters of bones and Zn retention in late phase of layer chicken production. It is hypothesised that different zinc source affect layers performances differently.

Introduction

Zinc is an essential element for many metabolic processes in living organisms and thus should be supplied in poultry diets. The main source of minerals used in animal feed is mineral salts which have low bioavailability. On the other hand, organic mineral sources such as zinc proteinate have been used increasingly in recent years due to their higher bioavailability but their use in animal feed is limited due to high cost (Zhao et al., 2014). With the introduction and advancement of nano technology, usage of nano particles (minerals) has gathered attention (Gao & Matsui, 2005), Recently, researchers have found that nano-silver, nano-selenium and ZnO nano-particles had a positive effect on broilers’ performances (Ahmadi et al., 2013).

Materials and methods

A total of 288 (White Hy – Line W36) laying hens at 64 weeks of age were distributed in a completely randomized experimental design with 4 treatments, 6 replicates and 12 birds for each experimental unit. Twelve weeks duration of dietary treatments included the corn–soybean meal-based diet (without Zn addition) and basal diet (zinc content of 21.4 mg/kg diet) supplemented with 80 mg/kg Zn-oxide, Zn-methionine, or Zn-nano-oxide (containing 101.4 mg/kg Zn). The recommended zinc level for layinig bird is 80 mg/kg Zn. Feeding programme, lighting schedule and housing temperature were as Hy-Line instruction. At the end of experiment, performance, egg production, egg quality of the birds and zinc content of tibia, egg, plasma and liver measured were evaluated according. The experimental protocol was approved by the animal welfare committee of Tarbiat Modares University, and the animals were handled and treated in a humane manner.

Results

The results showed that there were significant effects from Zn supplementation on egg mass (egg weight and egg production) feed conversion ratio, shell characteristic (strength and weight) and zinc content of various segments (P < 0.05). However, feed intake, live body weight gain, and egg parts (yolk and albumin) weight and characteristics such as yolk colour and Haugh unit (not presented here) were not influenced by dietary treatments. Overall Zn supplementation had improved shell strength though not shell weight (P < 0.05). Dietary Zn-nano-oxide supplementation increased shell strength compared to control and Zn oxide groups (P < 0.05). At the end of the experiment, the morphometric characteristics of the tibia such as tibia dry weight and length (not shown here) were not affected by dietary treatments but bone ash weight was significantly affected (P < 0.05). The Zn deposition in tibia and egg were significantly higher in birds fed Zn supplemented diets (P < 0.01). Plasma Zn status was not influenced by treatments. There was also significant effect of dietary zinc supplementation on zinc level of liver (P < 0.05) with nano zinc increasing zinc level of liver more than other zinc containing diet (Table 1).

Table 1. Effects of different sources of Zn on performance in laying hens.

Treatment	Egg Mass (g)	FCR (feed/EM)	Shell strength (kg)	Shell weight (g)	Tibia Zn (µg/g)	Egg Zn (µg/g)	Plasma Zn (mg/L)	Zn Liver (µg/g)	Bone ash weight (g)
Control	47.31^c	2.16^a	3.31^c	5.52	228.5^c	6.58^c	1.22	134.6^c	2.01^c
Zn-oxide	48.69^bc	2.12^ab	3.38^bc	5.5	252.9^b	9.89^b	1.51	153.2^b	2.11^bc
Zn-methionine	50.72^ab	2.02^b	3.57^ab	5.66	267.7^a	11.56^a	1.39	159.5^ab	2.23^ab
Zn-nano-oxide	51.61^a	2.01^b	3.64^a	5.64	272.9^a	12.04^a	1.47	162.4^a	2.30^a
SEM	0.64	0.02	0.04	0.09	3.21	0.53	0.01	2.65	0.04
P-value	0.009	0.03	0.007	0.06	<0.001	<0.001	0.07	<0.0001	0.02

^a,b,cMeans values within a column with no common superscript differ significantly (P ≤ 0.05).

SEM: standard error of means.

Conclusion

This study demonstrated that ZnO-NPs for dietary supplementation can improve the performance of laying hens. Therefore we concluded that ZnO-NPs can enhance zinc absorption in the intestine of aged layers and can be a more suitable source of zinc than to regular Zn-oxide in diets.

References

• Ahmadi, F., Khah, M. M., Javid, S., & Akradi, A. (2013). International Journal of Bioscience, 3, 95–100.
   Google Scholar
• Gao, X., & Matsui, M. (2005). Advance Materials, 17, 2037–2050.
   PubMed Web of Science ®Google Scholar
• Zhao, C. Y., Tan, X. Y., Xiao, X. S., Qiu, J. Q., & Pan, Z. X. (2014). Biological Trace Element Research, 160, 361–367.
   PubMed Web of Science ®Google Scholar

Investigations into the efficacy of novel antimicrobial peptides against Histomonas meleagridis, the causative agent of blackhead disease in poultry

J. Pickup

Queens University Belfast, UK

CONTACT J. Pickup [email protected]

Application

Combating blackhead disease, which causes mortality and morbidity in a wide range of gallinaceous fowl, through the administration of novel antimicrobial peptides.

Introduction

H. meleagridis predominantly affects turkeys, causing 80–100% mortality in a flock. The parasite initially infects the caeca of the host and if not treated will multiply to other organs, notably the liver causing liver necrosis and subsequent mortality. The infections appear sporadically and there is a range of hosts for the pathogen making development of control strategies challenging. Until recently the protozoal infection could be treated but the antimicrobial used was found to be carcinogenic and therefore was banned in the E.U in 2004 with most of the world following in 2014. The high mortality levels and the inability to treat H. meleagridis causes considerable economic loss to turkey farms. Coupled with this major concern is the fact that attempts to vaccinate so far have failed. Therefore, the need to develop a treatment is paramount for the poultry industry and ensuring future food security.

Materials and methods

H. meleagridis was cultured from turkey caecal samples collected form turkeys which had died due to infection. The dissection of the birds was carried out by vets in order to diagnose the cause of death. H. meleagridis was cultivated in growth flasks in Dwyer media for 72 h at 40°C. Extra rice powder was added at 48 h (Dwyer, 1970). The pathogen was allowed to reach 1 × 10–6 cells/ml before a challenge with novel antimicrobial peptides (AMPs) was performed. All of the AMPs were added at a concentration of 1024 mg/L, the AMPs were derived from the rumen microbiome (Oyama et al., 2017). The concentration of the pathogen was determined using a Haemocytometer post-staining with 0.4% trypan blue, and the cells were counted at 40 X magnification. The challenges were carried out in 96 well plates in triplicate for each AMP, and each concentration or each sample of H. meleagridis. The samples were left for 24 h before extracting DNA and microscopical counting and undertaking a qPCR on the samples to determine the concentration of H. meleagridis cells in the sample (Hussain et al., 2015). The average RFU value for each peptide was calculated and a single factor ANOVA was performed which generated the P value. Controls which had no AMP added were also set up.

Results

Peptides 1, 2, 3, 5, 6 and 7 showed a significant decrease in the expression of the FeHyD gene compared to an untreated sample, showing efficacy of those peptides against H. meleagridis (Table 1). Peptides 4 and 8 conversely showed no decreases in the FeHyD gene abundance, indicating little efficacy under the conditions tested.

Table 1. Quantitative PCR data for FeHyD gene indicating efficacy of the AMPs against Histomonas meleagridis following 24 h of exposure. RFU: relative fluorescence units.

Treatment	Average RFU value	SEM values	P value
Untreated control	255.99	10.37	P < 0.01
Pep 1	0.69	1.20	P < 0.01
Pep 2	0.10	0.78	P < 0.01
Pep 3	0.41	0.65	P < 0.01
Pep 4	476.18	18.44	P < 0.01
Pep 5	0.70	1.21	P < 0.01
Pep 6	−0.39	0.75	P < 0.01
Pep 7	−0.21	0.41	P < 0.01
Pep 8	310.94	15.05	P < 0.01

Conclusion

Novel rumen-derived AMPs 1, 2, 3, 5, 6 and 7 show promise for treatment of blackhead disease and are therefore worthy of further investigation. The AMPs could be administered to the turkey though its drinking water although there would have to be modification of the AMPs to survive the turkeys digestive track before reaching the caeca.

Acknowledgements

I would like to thank The British Poultry council for funding this work.

References

• Dwyer, D. M. (1970). Journal of Parasitology, 56, 192–200.
   Web of Science ®Google Scholar
• Hussain, I., Jaskulska, B., Hess, M., & Bilic, I (2015). Veterinary Parasitology, 121, 382–388.
   Google Scholar
• Oyama, L., Girdwood, S., Cookson, A., Fernandez-Fuentes, N., Prive, F., Vallin, H., Wilkinson, T., Golyshin, P., Golyshina, O., Mikut, R., Hilpert, K., Richards, J., Wootton, M., Edwards, J., Maresca, M., Perrier, J., Lundy, F., Luo, Y., Zhou, M., Hess, M., Mantovani, H., Creevey, C., & Huws, S. A. (2017). Npj Biofilms and Microbiomes, 3(1), 33
   Google Scholar

The influence of Fenugreek (Trigonella foenum-graecum L.) Garden cress (Lepidium sativum) supplementation on growth performance and cell-mediated immunity of broilers

I. Al-Homidan, T. Ebeid, A. Al-Muzaini, O. Abou-Emera and M. Fathi

Qassim University, Burahyda, Saudi Arabia

CONTACT A. Al-Muzaini [email protected]

Application

Use of natural feed additives could be widely accepted to improve growth performance and health in broilers.

Introduction

Today, poultry scientists are challenged to find out new alternatives to antibiotic growth promoters with no side effects. There has been an increasing trend towards using natural feed additives in the world. Many investigators reported that supplementing broiler’s diet with Fenugreek seeds or Garden cress improves productive performance and immune response (Alloui et al., 2012; Murwani, 2008). Fenugreek seeds contain bioactive compounds, including flavonoids, saponins, coumarin, galactomannan and trigonelline which have anti-inflammatory and immunomodulatory effects (Bahmani et al., 2016). Cress bean contains benzyl isothiocyanate which acts as an anti-bacterial agent (Lee et al., 2009). Therefore, the aim of the present study was to evaluate the growth performance and immune response of broilers given fenugreek or garden cress beans.

Materials and methods

A total of 1050 one-day-old broiler chicks (Ross 308) were grown over a period of 42 days. The chicks were individually weighed and randomly divided into seven different dietary treatments. Fenugreek (F) seeds and garden cress (G) as a powder were added to diet at different levels (0, 0.5% F, 1.5% F, 2.5% F, 0.5% G, 1.5% G, 2.5% G). Each dietary group has 6 replicates (25 chicks each). Feed and water were provided ad libitum. All birds were raised under similar husbandry and environmental conditions. Body weight, feed consumption and feed conversion ratio were determined weekly. To examine cell-mediated immune response, 70 chicks were used (10/treatment group). Each chick was intradermally injected into the right toe web with 100 μg Phytohemagglutinin-P (PHAP) (Sigma Chemical Co., St. Louis, MO 63178) in 0.1 mL sterile saline. The thickness of resulting swollen was measured with a constant tension caliper before injection and at 24, 48 and 72 h after PHAP injection. The immune response was calculated as the difference between its thickness before and after injection. The care and handling of the birds were in accordance with regulations of animal care committee of Qassim University. Data was subjected to a one-way analysis of variance with dietary treatment as a fixed factor using JMP (SAS).

Results

As shown in Table 1, adding 1.5% and 2.5% F and 2.5% G significantly decrease (P < 0.04) body weight. Also, a deterioration in FCR was detected in treatment groups fed a diet supplemented with fenugreek or garden cress. A numerical improvement (P > 0.05) in cell-mediated response of broilers fed a diet supplemented with 2.5%G was noticed at all studied times after PHAP injection compared with control birds. Additionally, inclusion of fenugreek or garden cress in the level of 0.5 or 2.5 numerically lowered mortality rates.

Table 1. Effect of fenugreek and garden cress dietary supplementation on growth performance and immune response of broilers.

		Fenugreek			Garden Cress
Item	Control	0.5%	1.5%	2.5%	0.5%	1.5%	2.5%	SEM	P-value
Live body weight g	2884^a	2858^ab	2759^cd	2709^d	2871^bc	2821^cd	2792^bcd	13.12	0.04
Feed consumption g	4355^bc	4383^abc	4438^ab	4445^a	4379^bc	4272^c	4307^ab	11.68	0.02
FCR	1.51^d	1.54^cd	1.61^ab	1.64^a	1.55^bcd	1.55^bcd	1.59^abc	0.0078	0.0004
CMI
24 h post injection	1.12	1.02	1.17	1.04	1.3	1.2	1.3	0.037	0.23
48 h post injection	0.97	0.74	0.92	0.80	1.11	0.84	1.08	0.045	0.21
72 h post injection	0.73	0.53	0.76	0.73	0.68	0.73	0.98	0.042	0.21
Mortality rate, %	2.7	1.4	2.4	0.9	1.5	2.4	1.4	0.22	0.18

^a,b,c,d Means within rows with no common letters are significantly differed.

FCR: feed conversion ratio (g feed/g gain); CMI: cell-mediated immunity.

Conclusion

In conclusion, supplementing a diet with fenugreek or garden cress did not improve growth performance in broilers. Cell-mediated response increased in chicks fed a diet supplemented with 2.5% garden cress.

References

• Alloui N., Ben S., Alloui M. N., & Ibrir F. (2012). Journal of World’s Poultry Research, 2, 25–27.
   Google Scholar
• Bahmani, M., Shirzad, H., Mirhosseini, M., Mesripour, A., & Rafieian-Kopaei, M. (2016). Evidence-Based Complementary and Alternative Medicine, 21, 53–62.
   Google Scholar
• Lee, Y. M., Seon, M. R., Cho, H. J., Kim, J. S., & Park, J. H. Y. (2009). Journal of Molecular Medicine, 87, 1251–1261.
   PubMed Web of Science ®Google Scholar
• Murwani R. (2008). International Journal of Poultry Science, 7, 497–501.
   Google Scholar

Amino acid digestibility varies between different wheat varieties for broiler chickens

R. Azhar^a, S. P. Rose^a, M. R. Bedford^b and V. R. Pirgozliev^a

^aNational Institute of Poultry Husbandry, Harper Adams University, Newport, Shropshire, UK; ^bAB Vista, Marlborough, UK

CONTACT R. Azhar [email protected]

Application

There are differences in ileal amino acid digestibility of feed wheat varieties that should be considered at the diet formulation stage of broiler chicken diets where possible.

Introduction

Wheat is often the only cereal used in broiler feed formulations in many European countries, so its nutritional value and variations in feeding quality have significant commercial importance. Investigation of wheat characteristics and determination of amino acid digestibility is important for economical diet formulation and to closely match the requirements of broilers. The aim of this study was to evaluate the differences in amino acid digestibility of modern UK feed wheat varieties and to test the hypothesis of a variety × growing site interaction.

Materials and methods

All procedures were approved by the Harper Adams University Research Ethics Committee. Two current UK feed wheat cultivars, Leeds (soft, mean endosperm hardness EH 29) and Santiago (hard, EH 79) from 4 growing sites (Nottinghamshire, Yorkshire, Lincolnshire and Cambridgeshire) were analysed for proximate analysis, physical characteristics and amino acid contents. Eight diets were formulated, all of which included the wheat sample at 670 and 330 g/kg of a balancer. Three additional diets containing 470, 570 and 770 g/kg of one wheat sample were formulated to test linearity. The diets were made iso-nitrogenous by adding wheat protein isolate. Titanium dioxide (TiO₂) was added as an indigestible feed marker for digestibility determination. A total of 320 male Ross 308 broilers were allocated to 64 raised floor pens (5 birds per pen). Each diet was replicated eight times, in a randomised complete block design. Birds were fed ad libitum a mash diet from 0 to 7 d and pellet diets 7–21 d. Feed intake and weight gain was recorded from 0 to 21 d. At day 21, ileal digesta was collected per pen. Apparent ileal digestibility of amino acids (AAD) of wheat was determined by the substitution method (Finney, 1978). Data were statistically compared by two-way ANOVA using 2 × 4 factorial design in GenStat (18th edition).

Results

The mean AAD (Table 1) of wheat samples were 0.856 for indispensable (IAA), 0.841 for dispensable (DAA) and 0.849 for total amino acids (TAA). Santiago had higher (P < 0.05) mean digestibility of lysine, leucine, histidine and valine than Leeds. Santiago had also higher (P < 0.001) phenylalanine digestibility. Santiago had higher (P < 0.001) TAA, IAA and DAA (P < 0.05) than Leeds. There was no difference in AAD between different sites except threonine, where Nottinghamshire had higher (P < 0.05) threonine digestibility than Lincolnshire or Yorkshire. The digestibility coefficient of TAA and DAA from Nottinghamshire were higher (P < 0.05, P < 0.001 respectively) than Lincolnshire and Yorkshire. There was no difference in the digestibility coefficient of IAA between growing sites. No interaction was observed between variety and growing site of wheat.

Table 1. Coefficient of amino acid digestibility of two wheat cultivars, at four geographical locations, for broiler chickens.

	Cultivar		Site				SEM*		Significance
	Leeds	Santiago	Camb^1	Lincoln^2	Nottin^3	York^4	Cultivar	Site	Cultivar	Site
Lysine	0.820	0.861	0.841	0.846	0.857	0.817	0.0114	0.0161	0.015	0.353
Threonine	0.764	0.801	0.778^ab	0.754^a	0.859^b	0.737^a	0.0205	0.0290	0.210	0.022
Methionine	0.870	0.901	0.864	0.895	0.893	0.890	0.0228	0.0323	0.349	0.896
Leucine	0.862	0.896	0.886	0.881	0.893	0.856	0.0092	0.0130	0.013	0.229
Isoleucine	0.845	0.879	0.877	0.867	0.879	0.825	0.0130	0.0184	0.068	0.153
Phenylalanine	0.863	0.901	0.881	0.887	0.891	0.869	0.0079	0.0111	0.001	0.520
Histidine	0.835	0.873	0.855	0.856	0.872	0.833	0.0087	0.0123	0.003	0.175
Valine	0.775	0.835	0.805	0.803	0.829	0.784	0.0131	0.0186	0.002	0.407
Arginine	0.902	0.927	0.911	0.918	0.920	0.910	0.0096	0.0136	0.069	0.936
TAA	0.832	0.866	0.860^bc	0.834^ab	0.877^c	0.825^a	0.0069	0.0098	0.001	0.002
IAA	0.837	0.875	0.855	0.856	0.877	0.836	0.0073	0.0103	<.001	0.056
DAA	0.827	0.855	0.866^b	0.808^a	0.876^b	0.814^a	0.0090	0.0127	0.029	<.001

Means within a row with no common superscript are different; *Pooled standard error of the means, ¹Cambridgeshire, ²Lincolnshire, ³Nottinghamshire, ⁴Yorkshire.

Conclusion

There are differences in TAA, IAA and DAA between two wheat varieties. In this study, the AA digestibility of hard feed variety was higher than the soft wheat.

Reference

• Finney, D. J. (1978). Statistical Method in Biological Assay (3rd ed).
   Google Scholar

Gizzard pH in broiler chicks in the immediate post placement period

N. Morgan^a, P. Garland^b, D. V. Scholey^c and E. J. Burton^d

^aUniversity of New England, Armidale, Australia; ^bPremier Nutrition, Rugeley, UK; ^cNottingham Trent University, Nottingham, UK

CONTACT N. Morgan [email protected]

Application

Greater understanding of gizzard pH may lead to the development of a targeted, strategic approach to optimise efficiency of exogenous digestive enzyme diet supplementation in the post-hatch period.

Introduction

Gizzard pH effects the solubility of minerals and the efficacy of enzymes, and small changes outside the optimum pH range can have a huge impact on nutrient digestibility and absorption. It is well established that gizzard pH varies significantly with bird age (Morgan et al., 2014), but little is known about the pH in the gizzard of broiler chicks in the immediate post placement period, when the chicks first have access to feed. With the rise in interest in specific pre-starter diets, it becomes increasingly of interest to be aware of the initial conditions in the gut, in order to correctly formulate feeds for this stage. The aim of this study was determine how gizzard pH changes with age in broilers in the immediate post placement period.

Materials and methods

Two separate trials were conducted to assess gizzard pH in broilers in the immediate post placement period and both were reviewed by the NTU college ethics committee prior to commencement. In trial 1, 66-d-old male Ross 308 chicks were weighed and then allocated to 3 floor pens, 22 birds per pen, based on hatch weight (35–39 g, 40–44 g and 45–49 g). These birds were fed a commercial wheat-soya based diet, fed as. Fifteen birds, 5 birds from each pen, were sampled at 0, 24, 48 and 72 h post-hatch, at the same time each sampling day. In trial 2, 72-day-old-male Ross 308 were weighed and then randomly assigned to 6 floor pens of equal weight, 12 birds per pen. These birds were fed a commercial maize-soya based diet, fed as mash. Twelve birds, 2 birds per pen, were sampled at d4, 6, 8, 10, 12 and 14 post-hatch, at the same time each sampling day. In both trials, feed and water was available ad libitum, and care was taken to ensure the birds ate and drank as soon as possible. All birds sampled were euthanised by cervical dislocation and the gizzard immediately excised. Gizzard pH was measured in triplicate by inserting a spear tip piercing pH electrode (Sensorex, California, USA) directly into the digesta in the gut lumen. The impact of bird age on gizzard pH was statistically analysed using one way ANOVA in SPSS v21, with Duncan post hoc testing to elucidate differences.

Results

The mean gizzard pH for each sampling time point determined in Trial 1 is shown in Figure 1. Gizzard pH was significantly higher (P < 0.001) in the birds at the initial sampling time point (at placement) compared to the subsequent time points. There was substantial bird to bird variability, with bird pH varying from 3.2 to 5.7 at placement and from 1.9 to 4.6 at 72 h post-hatch. Figure 2 illustrates that age also had a significant (P = 0.025) impact on gizzard pH from d4–14 post-hatch; pH was lower at d14 compared to in younger birds, and was highest at d4 and d8.

Figure 1. Gizzard pH 0–72 h post-hatch (n = 15 birds per time point).

Figure 2. Gizzard pH 4–14 days post-hatch (n = 12 birds per time point).

Conclusion

The high pH observed on day of hatch likely indicates immaturity of the gizzard and lower feed intake compared to the older birds. There was a trend that as bird age increased gizzard pH decreased, which may represent increased Ca solubility, meaning less Ca was present in the gut lumen to influence pH. Improved understanding of digestive tract pH in young birds could lead to a targeted, strategic approach when developing exogenous digestive enzymes to be supplemented in pre-starter diets, such as producing enzymes with a pH optimum matching post-hatch pH or tailoring enzyme use to specific key diet phases.

Reference

• Morgan, N. K., Walk, C. L., Bedford, M. R., & Burton, E. J. (2014). Poultry Science, 93, 354–363.
   PubMed Web of Science ®Google Scholar

Reducing the impact of enteritis on bird performance using oregano essential oil

D. Harrington^a, H. Hall^a, S. Srinongkote^b and W. Wakeman^a

^aAnpario Plc, Worksop, UK; ^bAnimal Nutrition Consultant, Bangkok, Thailand

CONTACT D. Harrington [email protected]

Application

There is a refocusing of interest on feed additives to help manage poultry enteric health in the face of measures to reduce antibiotic use. This study demonstrated that an oregano-based eubiotic can ameliorate the impact of necrotic enteritis on broiler performance and intestinal health.

Introduction

Costs associated with enteritis in poultry have been estimated at up to £4.5 billion for the global poultry industry (Wade & Keyburn, 2015). Interest in antibiotic alternatives as part of gut health management has increased due to regulatory and consumer pressure to reduce antibiotic usage in livestock production. Botanical products based on essential oils are one group of additives that have demonstrated promise as part of an antibiotic reduction programme (Murugesan et. al. 2015). A study was undertaken to determine the performance of broilers fed a commercial oregano oil (OEO) product (Orego-Stim (Anpario plc, UK)) and challenged with Clostridium perfringens.

Materials and methods

A study was undertaken to determine the performance of broilers fed a commercial oregano oil product and challenged with Clostridium perfringens. A total of 168 Ross 308 broilers were assigned to 2 treatment groups (14 birds/pen, 6 replicates/treatment): (1) Control (CON): basal ration and (2) OS: basal ration + OEO at 300 g/tonne feed. The basal ration contained meat and bone meal in all three feed phases (3–5% depending upon feeding phase). The study duration was 35 days. Birds were housed in floor pens on clean litter with access to feed and water ad libitum. On day 7, birds were orally administered a mixture of Eimeria acervulina, E. maxima and E. tenella (15,000 oocysts/ml) followed by an oral dose on days 12, 13 and 14 of C. perfringens (3 × 10⁹ cfu/ml, 3 ml/bird) on each day. Performance was determined for 0–10, 10–24, 24–35 and 0–35 days. On day 18, 2 birds/pen were euthanased to determine clostridial lesion score (LS) where 0 = no apparent lesion, 1 = thin friable small intestine, 2 = focal necrosis, ulceration or both, 3 = patchy necrosis, 4 = severe extensive mucosal necrosis. Data were analysed by ANOVA using Minitab (Minitab Inc.) and significance declared at P < 0.05. All procedures were conducted according to the prevailing national legislation on the use of animals in research.

Results

Body weight gain was numerically but not significantly higher in OS versus CON for all time points (Figures 1 and 2). With the exception of 0–10 days when FCRs were similar, OS had consistently lower, but not significantly so, FCR than CON (Figure 2). Overall (0–35 d), FCR was 3.7% lower in OS versus CON. LS was significantly lower (P < 0.05) by 42% in OS versus CON on day 18 (0.86 and 1.22, respectively).

Figure 1. Body weight gain (kg) for 0–10, 10–24, 24–35 and 0–35 days. Error bars ± SD.

Figure 2. FCR for 0–10, 10–24, 24–35 and 0–35 days. Error bars ± SD.

Conclusion

An oregano oil-based eubiotic (Orego-Stim) reduced intestinal damage associated with necrotic enteritis following Eimeria and clostridial challenge.

References

• Murugesan, G. R., Syed, B., Haldar, S., & Pender, C. (2015). Frontiers in Veterinary Science, 2, 21.
   PubMed Web of Science ®Google Scholar
• Wade, B., & A. Keyburn. (2015). World Poultry, 31, 16–17.
   Google Scholar

An examination of bio-available and total silicon in broiler chickens through evaluation of the solid and aqueous phases of digesta

H. Hayton, S. Prentice, D. V. Scholey and E. J. Burton

Nottingham Trent University, Nottinghamshire, UK

CONTACT S. Prentice [email protected]

Application

The supplementation of a novel form of silicon (Si) into the diets of poultry at NTU has been shown to incorporate Si into the serum with positive effects on bird performance in the initial 3 weeks post hatch.

Introduction

There is some evidence that supplementation of Si may alleviate skeletal disorders due to its role in bone formation, growth and mineralisation (Carlisle, 1970), yet the mechanism for absorption remains unclear, as bioavailability of Si sources can be poor. This study aims to investigate the uptake and solubility of a novel Si supplement, via its presence in the blood, which has been previously shown to have increased bioavailability, along with its partitioning between the solid and aqueous phases of digesta at various sites of the gastrointestinal tract. It is expected that there will be no negative impact on performance data.

Materials and methods

Male Ross 308 broilers (n = 576) were allocated to 24 plots with 12 replicate plots per diet. Each plot was comprised of 2 pens containing 12 birds per pen. Plots were allocated to either a standard (control) diet or an identical diet supplemented with Si at 1000 ppm. Diets were wheat soya-based diets formulated to meet the age and strain of the bird, and fed as mash in one phase. Feed and water were available ad libitum and birds were bedded on shavings. Birds and feed were weighed weekly, and blood collected post mortem from one bird per pen weekly to ensure Si uptake. Digesta was pooled from 4 birds per plot on d21 from jejunum and ileum. The solid and aqueous phases were separated via the method of Pang and Applegate (2007) and the bio-available Si measured in triplicate for each phase using a molybdenum blue method. Data were analysed using IBM SPSS V.24, and all work undertaken was approved by the ARES ethics committee.

Results

Data for bird performance and Si absorption into the bloodstream (Table 1) shows that Si is incorporated into the plasma by d7 (data not shown) and maintained until d21, with a resulting increase in bodyweight gain.

Table 1. Cumulative performance data for day 0–21 of Si trial and plasma Si content on d21 (S.E.).

Diet	d0–21 BWG/bird (g)	d0–21 FI/bird (g)	d0–21 FCR	d21 plasma Si (mgl^−1)
Control	717.56 (25.325)	1051.27 (19.026)	1.48 (0.036)	1.75 (0.104)
Si 1000ppm	792.30 (22.712)	1107.70 (21.358)	1.41 (0.028)	5.16 (0.475)
P value	0.040	0.064	0.129	<0.001

Bioavailable Si levels in the digesta for ileum and jejunum are shown below in Table 2. The test diet had significantly more silica in both aqueous and solid phases with the majority of the Si residing in the solid phase.

Table 2. Bioavailable Si in ileal and jejunal digesta on d21 of trial (S.E.).

	Si in solid phase of digesta/mgl^−1		Si in aqueous phase of digesta/mgl^−1
Diet	Jejunum	Ileum	Jejunum	Ileum
Control	232.797 (22.88)	63.535 (5.17)	33.308 (3.97)	52.976 (4.23)
Si 1000ppm	367.534 (26.47)	250.942 (12.46)	50.387 (8.37)	60.765 (4.03)
P value	<0.001	<0.001	0.006	0.054

Conclusion

These results indicate that the Si supplement is successfully absorbed and has potential positive effects on bird performance. The solid and aqueous partitioning shows that most Si is transported in the solid phase of the digesta and that the absorption continues to the terminal end of the ileum. Further assessment of the mode of action of the Si needs to be undertaken.

Acknowledgements

Hana Hayton would like to thank the WPSA for the summer vacation scholarship supporting this project.

References

• Carlisle, E.M., (1970). Science, 167, 279–280.
   PubMed Web of Science ®Google Scholar
• Pang, Y., Applegate, T. J., (2007). Poultry Science, 86, 531–537.
   PubMedGoogle Scholar
• Short, F. J., Burton, E. J., Belton, D. J., Mann, G. E., & Perry, C. C. (2011). British Poultry Abstracts, 7, 2–3.
   Google Scholar

The effect of silica supplementation on bone parameters in broiler chickens

M. Bradley, S. Prentice, D. V. Scholey and E. J. Burton

Nottingham Trent University, Nottinghamshire, UK

CONTACT S. Prentice [email protected]

Application

Supplementing poultry diets with silicon could help alleviate lameness in poultry by improving skeletal integrity, thus reducing the economic and welfare issues associated with this condition.

Introduction

Poor skeletal integrity due to the rapid growth rates of broiler chickens continues to pose a significant concern for the poultry industry, both from a welfare and economic perspective. Silica (Si) is suggested to be connected to the calcification and development of bone, with deficiencies associated with skeletal weaknesses. Research in broilers at NTU (Short et al., 2011) has indicated that Si supplementation may improve tibial strength but the potential effect on growth plate morphology has not been assessed. The aim of this study was to compare the histological and morphological properties of tibias from birds fed diets supplemented with Si compared to a control diet.

Materials and methods

Male Ross 308 broilers (n = 576) were allocated to 24 plots with 12 replicate plots per diet. Each plot was composed of 2 pens containing 12 birds each. Plots were allocated to either a standard (control) diet or an identical diet supplemented with Si at 1000 ppm. Diets were wheat soya-based diets formulated to meet the age and strain of the bird, and fed as mash in one phase. Feed and water were available ad libitum and birds were bedded on shavings. Performance was recorded weekly. On d21, one tibia was removed from each plot. Bones were weighed, measured and broken using a TA-XT plus Texture Analyser with a 3 point bend fixture. The tibial epiphysis was removed, de-calcified for 6 weeks in EDTA then paraffin embedded for histological examination. Six slides were cut from each epiphysis and stained using H&E. The width of the resting, proliferative and hypertrophic zones of the growth plates were measured using Image J. Data were analysed using IBM SPSS 24. All work done received prior approval from the ARES ethical review board.

Results

Tibias were heavier, longer and stronger in birds fed 1000 ppm Si (Table 1) and resting growth plate zone was significantly larger in those birds (Table 2). There were no differences in other areas of the tibial growth plate. Birds were heavier in the supplemented group.

Table 1. Tibia measures and body weight in birds fed diets with and without silica.

Measurement	Control	Si@1000ppm	P value
Weight/mm (±SE)	5.65 (0.162)	6.59 (0.153)	<0.001
Length/mm (±SE)	70.44 (0.617)	74.10 (0.525)	<0.001
Breaking strength/N/kg BW (±SE)	179.35 (11.691)	207.01 (6.190)	0.055
Body weight/g (±SE)	727.25 (23.956)	848.03 (28.314)	0.005

Table 2. Comparison of growth plates in birds fed diets with and without silica.

	Width of growth plate zone/µm (±SE)
Diet	Resting	Proliferative	Hypertrophic
Control	569.5 (39.68)	397.8 (12.89)	347.7 (7.76)
Si @1000ppm	712.4 (45.44)	393.5 (9.80)	351.2 (8.02)
P value	0.020	0.782	0.544

Conclusion

Feeding silica at 1000 ppm improved breaking strength of tibias, although this could be related to the increased bone weight and length. The resting growth plate is an important contributor to growth plate function and is the site for the origination of chondrocytes but the increase in size of this area in birds fed Si needs further investigation.

Acknowledgements

The authors gratefully acknowledge funding from AB Vista for the Silica project. Michael Bradley was `in receipt of a NTU poultry research summer studentship.

Reference

• Short, F. J., Burton, E. J., Belton, D. J., Mann, G. E., & Perry, C. C. (2011). British Poultry Abstracts, 7(1), 2–3.
   Google Scholar

The effect of feeding different selenium sources on the antioxidant status of broiler chickens

S. Woods^a, I. M. Whiting^a, S. P. Rose^a, D. Bravo^b, S. Sobolewska^a and V. R. Pirgozliev^a

^aHarper Adams University, Edgmond, Newport, UK; ^bInVivo Animal Nutrition and Health, Talhouët, Saint-Nolff, France

CONTACT V. R. Pirgozliev [email protected]

Application

Dietary supplementation with Se improves overall antioxidant status of the birds, although different sources of dietary Se may possess different bioavailability for broiler chickens.

Introduction

Free radicals produced during normal metabolism can induce body damage if optimum levels are exceeded (Surai, 2002). Under normal conditions, excessive reactive oxygen species are eliminated by body antioxidant systems. A high antioxidant status is a major factor that can positively affect bird performance and productivity in commercial conditions. Minerals, such as selenium (Se) are necessary for the proper functioning of the antioxidant system. Surai (2002) describes Se as the ‘chief antioxidant’ because of the important role it has with other antioxidants. Therefore, supplementing diets with Se may enhance the antioxidant system of birds and mitigate the effects of oxidative stress. This study evaluated the effect of various sources of dietary Se on growth performance and antioxidant capacity (determined as glutathione peroxidase [GSH-Px] activity in blood, and Se contents in liver and breast muscle) in broilers.

Materials and methods

The study was approved by the Harper Adams University Research Ethics Committee. Two hundred and fifty day-old male Ross 308 chicks were obtained from a commercial hatchery and allocated to 50 solid floor pens (0.6 m x 0.6 m) with 5 birds in each. Broilers were fed 1 of 5 wheat soybean-based mash diets: a positive control (PC) formulated to be nutritionally adequate (containing sodium selenite protected premix with a potency of 4.50% Se, at 5.55 g/t); a negative control (NC) with the same formulation like PC but without supplementary Se (background Se only); NC + 10.35 g/t XSEL3.0 (Pancosma SE, Switzerland) (diet NC + XSEL); NC+136.36 g/t selenized yeast (NC + SY); NC + 0.666 g/t sodium selenite (NC + SS). There were two dietary phases, from 0 to 21 days of age and from 21 to 35 days of age. Birds had free access to feed and water. Growth performance was measured from 0 to 35 days old. At 35 days old one bird per pen was killed. Se was measured in the liver and breast meat, and glutathione levels (GSH-Px) were measured in the blood. The results were statistically compared using a randomised block ANOVA. Duncan’s multiple range test was used to determine significant differences between diets.

Results

Birds fed NC + SY had the lowest FI and WG (P < 0.05) although there was no difference (P > 0.05) in performance between birds fed PC and NC. The FI and WG of birds fed diet NC + XSEL were not different (P > 0.05) than those fed PC, but higher (P < 0.05) than those fed diet NC + SY. Birds fed any form of Se had higher (P < 0.001) Se concentration in tissue and higher GSH-Px compared to NC fed birds (P < 0.001). However, birds fed NC + SY had higher (P < 0.001) Se concentration in breast tissue, the same (P > 0.05) Se concentration as PC in liver but higher (P < 0.001) than the rest, and numerically higher (P > 0.05) GSH-Px (Table 1).

Table 1. The effects of supplementary Se sources on broilers feed intake (FI), weight gain (WG), feed conversion ratio (FCR), Se in liver and breast, and glutathione peroxidase (GSH-Px) in blood.

Diet	FI 0–35 (g/b/d)	WG 0–35 (g/b/d)	FCR 0–35	Se liver (mg/kg wet weight)	Se breast meat (mg/kg wet weight)	GSH-Px blood (U/g HB)
PC	96.6^c	59.1^c	1.695	0.694^cd	0.148^b	170^a
NC	94.8^bc	58.3^bc	1.641	0.375^a	0.113^a	40^b
NC + XSEL	95.3^bc	57.9^bc	1.687	0.660^bc	0.151^b	154^a
NC + SY	90.5^a	54.9^a	1.671	0.735^d	0.274^c	170^a
NC + SS	92.1^ab	56.1^ab	1.679	0.648^b	0.149^b	149^a
SEM	1.41	0.91	0.0535	0.0149	0.0029	12.9
P	0.028	0.016	0.965	<0.001	<0.001	<0.001

No common lettering indicates that there is a significant difference between treatments (P<0.05).

Conclusion

Dietary Se can be provided in different forms that may vary its bioavailability. Since Se is an important factor in the bird’s ability to cope with stress, and the overall health of the birds, understanding the bioavailability in dietary Se supplements for broilers warrants further investigation.