Effects of sunflower meal supplementation in the diet on productive performance, egg quality and gastrointestinal tract traits of laying hens

ABSTRACT

1. A trial was conducted to study the effects of additional dietary fibre (DF), resulting from partial replacement of soybean meal (SBM) with high-fibre sunflower meal (SFM), on egg production and gastrointestinal tract (GIT) traits in laying hens.

2. A total of 480 Nick Chick white laying hens (21 weeks of age) were randomly assigned to three dietary treatments and fed for 24 weeks. The hens were fed either the control diet based on corn and SBM, which contained 30 g/kg crude fibre (CF) without SFM, or test diets containing 40 g more CF/kg from adding 47 g/kg SFM or 50 g more CF/kg from adding 97 g SFM/kg. Each dietary treatment was replicated eight times (20 hens per replicate).

3. Body weight (P < 0.05), egg production rate (P < 0.05), egg weight (P < 0.01) and egg mass (P < 0.01) linearly increased but feed conversion ratio linearly decreased (P < 0.01) with increasing SFM supplementation. Feed intake, cracked/broken egg ratios and shell less egg ratios were comparable amongst the groups.

4. The egg quality indices were not influenced by dietary treatments, except for the Haugh units, which decreased (linear, P < 0.01; quadratic P < 0.05) when SFM was added.

5. Digestive organ size was not affected by the dietary treatments, but caecum length increased in hens fed SFM (P < 0.05). Digesta pH in the ileum and caecum was reduced linearly (P < 0.01) with SFM supplementation.

6. Small intestine morphology traits improved with 47 g SFM/kg supplementation, whereas negative effects were observed with 97 g SFM/kg.

7. Productive performance of laying hens improved with 40 or 50 g/kg more CF in feed, mostly from SFM supplementation. It was concluded that this performance increase was attributed mostly to the increase in fat content, rather than DF level, when high-fibre SFM was included in layer diets.

KEYWORDS:

• Dietary fibre
• digestive organ size
• intestinal morphology
• laying hen
• sunflower meal

Acknowledgments

The authors wish to thank to director and technicians of Adnan Menderes University Agricultural Biotechnology and Food Safety Application and Research Center (ADU-AgBioCenter, TARBIYOMER) for their support and contribution in performing the histomorphological analysis.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

This project was supported by Republic of Turkey Ministry of Food, Agriculture and Livestock, Project No: TAGEM/HAYSÜD/14/06/02/03.