Assessment of caecal parameters in layer hens fed on diets containing wheat distillers dried grains with solubles

Abstract

1. There is much interest in quantifying the nutritional value of UK wheat distillers dried grains with solubles (W-DDGS) for livestock species. A study was designed to evaluate caecal parameters (pH, short chain fatty acids (SCFAs) and bacterial diversity) in layer hens fed on balanced diets containing graded concentrations of W-DDGS.

2. A total of 32 layer hens (Bovans Brown strain at 27 weeks of age) were randomly allocated to one of 4 dietary treatments containing W-DDGS at 0, 60, 120 or 180 g/kg. Each treatment was fed to 8 replicate individually housed layer hens over a 5-d acclimatisation period, followed by a 4-week trial. Individual feed intakes were monitored and all eggs were collected daily for weeks 2, 3 and 4 of the trial, weighed and an assessment of eggshell “dirtiness” made. All hens were culled on d 29 and caecal pH and SCFAs measured. Polymerase chain reaction denaturing gradient gel electrophoresis of the bacterial 16 S rDNA gene was used to assess total bacterial diversity of luminal caecal content from hens fed the 0 and 180 g W-DDGS/kg diets. Unweighted pair group method with arithmetic mean (UPGMA) dendrograms were generated from DGGE banding patterns.

3. Increasing W-DDGS dietary concentrations resulted in a more acidic caecal environment. Caecal SCFAs were unaffected by diet aside from a quadratic effect for molar proportions of isobutyric acid. Diversity profiles of the bacterial 16S rRNA gene from luminal caecal contents were unaffected by W-DDGS inclusion.

4. The results of the current study suggest that W-DDGS can be successfully formulated into nutritionally balanced layer diets (supplemented with xylanase and phytase) at up to 180 g/kg with no detrimental effects to the caecal environment.

ACKNOWLEDGEMENTS

Technical input from Dr Robert Linforth (Division of Food Sciences), Neil Saunders (Division of Animal Sciences) and the Bio Support Unit (University of Nottingham) is gratefully acknowledged. The authors also wish to thank Dr Oluyinka Olukosi (SRUC) for useful advice and Dr Lorraine Salmon (Premier Nutrition) and Dr Helen Masey O’Neill (AB Vista Feed Ingredients) for diet formulation and supply of enzymes used in this study.

Additional information

Funding

This research was carried out as part of the Environmental and Nutritional Benefits of Bioethanol Co-products (ENBBIO) project, supported by ABAgri Ltd, AB Vista Feed Ingredients, ADAS Ltd, Aunir, Agriculture and Horticultural Development Board-BPEX, EBLEX, Dairy-Co and HGCA divisions, Noble foods, Ensus PLC, Evonik Industries, Glencore Grain UK Ltd, Hook2Sisters, Marks and Spencer PLC, NEPIC, Premier Nutrition, Sciantec Analytical Services Ltd, Syngenta Seeds UK, Scotch Whisky Research Institute and Tulip Ltd, and sponsored by the UK Department for Environment Food and Rural Affairs, through the Sustainable Livestock Production LINK Programme.