Feeding dihydroquercetin in wheat-based diets to laying hens: impact on egg production and quality of fresh and stored eggs

Figures & data

Table 1. Formulation of the experimental basal diet.

Ingredients (g/kg)
Barley	100.0
Wheat	535.0
Soybean meal (48% CP)	175.0
Full fat soya	50.0
L Lysine	0.5
DL Methionine	1.5
Soya oil	20.0
Limestone	100.0
Monocalcium Phosphate	8.0
Salt	2.5
Sodium bicarbonate	1.5
Layer Vit-Min Premix^1	1.0
Titanium Dioxide	5.0
Determined values
Dry matter (g/kg)	905
Gross energy (MJ/kg)	14.63
Crude protein (g/kg)	167
Ether extract (g/kg)	48
Calcium (g/kg)	47.7
Total Phosphorus (g/kg)	5.5
Total carotenoids (µg/g)	0.627
Vitamin E (µg/g)	17.248
AME (MJ/kg)^2	11.56

¹The premix provided (units/kg diet) the following: ¹Premix (per kg feed): Vit A (retinyl acetate) 10.000 IE; Vit D3 (cholecalciferol) 2.000 IE; Vit E (dl-a-tocopherol) 25 mg; Vit K3 (menadione) 1,5 mg; Vit B1 (thiamine) 1,0 mg; Vit B2 (riboflavin) 3,5 mg; Vit B6 (pyridoxine-HCl) 1,0 mg; Vit B12 (cyanocobalamin) 15 µg; Niacin 30 mg; D-pantothenic acid 12 mg; Choline chloride 350 mg; folic acid 0,8 mg; Biotin 0,1 mg; Iron 50 mg; copper 10 mg; Manganese 60 mg; Zinc 54 mg; Iodine 0,7 mg; Selenium 0,1 mg. ²The value for AME was calculated.

Table 2. Effect of dietary dihydroquercetin (DHQ) on hen weight, feed intake and egg production over 4 weeks of feeding.

	C	DHQ	SEM	P
Hen start weight (kg)	1.854	1.786	0.0309	0.157
Hen end weight (kg)	1.959	1.897	0.0597	0.478
Weight gain hen period (kg)	0.105	0.111	0.0343	0.872
FI (g/b/d)	117.8	118.5	3.06	0.879
Egg mass (g/b/d)	54.78	53.09	1.136	0.320
Egg weight (g)	58.65	57.19	1.139	0.388
FCR egg production (kg:kg)	2.160	2.250	0.0955	0.521
Egg production (%)	93.5	92.8	1.55	0.763

C, control; SEM, pooled standard error of means; Data are means of 10 replicate cages with 4 birds per cage; P value describes significance between treatments determined by ANOVA; Results statistically significant P < 0.05.

Table 3. Effect of dihydroquercetin (DHQ) on egg and eggshell quality variables when fed to laying hens for 4 weeks.

	C	DHQ	SEM	P
Albumen height (mm)	8.44	8.38	0.408	0.919
Haugh unit	91.7	91.9	2.15	0.954
Albumen pH	8.43	8.43	0.060	0.991
Yolk pH	6.28	6.22	0.052	0.403
Eggshell thickness (mm)	0.333	0.354	0.0093	0.149
Eggshell weight (g)	5.20	5.37	0.157	0.475
Surface area (cm^2)	71.9	70.0	1.11	0.266
Shell thickness index mg/cm^2	72.3	76.7	1.88	0.131
DSM YolkFan^TM	2.30	2.20	0.299	0.811
Yolk colour:
L	82.6	81.6	2.09	0.723
a*	0.43	0.66	0.864	0.801
b*	17.49	16.24	1.263	0.349
Eggshell colour:
L	57.86	60.30	1.235	0.200
a*	20.50	18.62	0.845	0.156
b*	32.50	30.57	0.764	0.111
Deformities %
% cracked	1.47	1.66	0.489	0.792
% double yolk	3.08	1.81	0.732	0.252
% soft shell	0.88	0.43	0.309	0.334
% wrinkled	0.14	0.00	0.100	0.343

C, control; SEM, pooled standard error of means; Data are means of 10 replicate cages with 4 birds per cage; Colour system defined as L* indicates lightness, while a* and b* are chromaticity coordinates; P value describes significance between treatments determined by ANOVA; Results are statistically significant when P < 0.05.

Table 4. Proximate analysis, total carotenoid and vitamin E of the yolk and albumen and mineral analysis of the eggshell after feeding dihydroquercetin (DHQ) to laying hens for 4 weeks.

	C	DHQ	SEM	P
Yolk and albumen:
Dry matter (g/kg)	315.5	315.0	3.74	0.930
Crude protein (g/kg)	374.8	373.1	6.37	0.853
Crude fat (g/kg)	211.6	210.9	7.19	0.948
Total carotenoids (µg/g)	2.96	2.58	26.9	0.288
Vitamin E (µg/g)	42.5	44.3	18.1	0.629
Eggshell:
Calcium (g/kg)	82.5	83.5	2.09	0.750
Total Phosphorus (g/kg)	4.7	4.8	0.11	0.389
Ash (g/kg)	101.5	102.4	1.93	0.746

C, control; SEM, pooled standard error of means; Data are means of 10 replicate cages with 4 birds per cage; P value describes significance between treatments determined by ANOVA; Results are statistically significant when P < 0.05.

Table 5. Effect of length of storage on egg quality variables of laying hens fed dietary dihydroquercetin (DHQ) for 4 weeks.

	Egg weight (g)	Albumen pH	Albumen height (mm)	Haugh Units	Yolk pH	Yolk colour (DSM YolkFan)
DHQ
-	57.55	8.83	5.74	72.87	6.15	2.00
+	55.30	8.86	5.60	72.41	6.17	1.93
SEM	1.086	0.033	0.145	1.030	0.029	0.125
Storage (d)
0	57.85	8.43	8.41	91.78	6.25	2.25
14	56.09	9.03	4.66	66.45	5.98	1.45
28	55.33	9.09	3.95	59.69	6.25	2.20
SEM	0.570	0.040	0.178	1.262	0.036	0.153
DHQ × Storage (d)
− 0	58.99	8.43	8.44	91.69^a	6.28	2.30
− 14	56.81	9.01	4.49	64.32^b	5.94	1.40
− 28	56.86	9.06	4.30	62.59^b	6.22	2.30
+ 0	56.72	8.43	8.38	91.87^a	6.22	2.20
+ 14	55.38	9.05	4.82	68.57^c	6.03	1.50
+ 28	53.80	9.11	3.59	56.78^d	6.27	2.10
SEM	1.363	0.056	0.251	1.785	0.051	0.216
P-values
DHQ	0.181	0.504	0.478	0.754	0.528	0.707
Storage	0.015	<0.001	<0.001	<0.001	<0.001	<0.001
DHQ × Storage	0.587	0.892	0.124	0.025	0.289	0.780

C, control; SEM, pooled standard error of means; Data are means of 10 replicate cages with 4 birds per cage; P value describes significance between treatments determined by 2 × 3 factorial ANOVA; Results are statistically significant when P < 0.05.