Feeding motivation on the incidence of floor eggs and extraneously calcified eggs laid by broiler breeder hens

Abstract

1. Commercial broiler breeder hens lay many eggs on the floor rather than in nest boxes provided. A study was conducted to determine whether feeding feed-restricted broiler breeder hens during the sitting phase of nesting results in a higher incidence of floor eggs and/or retained eggs.

2. Sixty broiler breeder females (Ross 308) were randomly assigned to 6 deep litter pens containing 10 nest-boxes. At 35 weeks of age and for 9 weeks, feed was distributed to all pens at lights-on every second day (fed normally, FN). On alternate days (feeding delay, FD), feed was distributed when 2–3 hens/pen were sitting in a nest box. Behaviour was sampled at 41 weeks of age, for 26 d. Eggs and egg location data were collected daily, and eggs were scored for extra-cuticular calcium.

3. Of 81 instances in which the hen was sitting firmly in a nest box at the time of feeding, on 80 instances the hen left the nest-box to feed, and on one instance the hen laid her egg then exited to the feeder. Of these 80 instances, on 58 occasions the hen returned to a nest-box to lay her egg; on 12 the hen returned to the nest-box but laid no egg; on 7 the hen did not return to the nest box and laid no egg; and on three the hen laid her egg on the floor.

4. Mean floor egg percentage was 13·3 ± 3·2% on FN and 13·3 ± 4·7% on FD days; these did not differ significantly.

5. The mean extra-cuticular calcium score over all pens was 0·9 ± 0·06 on FN days and 1·2 ± 0·06 on FD days; these differed significantly.

6. In conclusion, feeding broiler breeder hens during nesting results in a conflict between feeding and nesting motivation and higher numbers of extraneously calcified eggs, but does not result in a significant increase in floor eggs even though nesting hens will leave the nest box for food.

Acknowledgements

We would like to thank the Ontario Ministry of Agriculture, Food and Rural Affairs for the financial support of this research project and to Ross Breeders Inc. for graciously donating the birds. A sincere thank-you is also extended to the Arkell Poultry Research station staff for service in the poultry house, to Stella Letic for her commitment and diligence in data collection assistance, and to Tina Widowski for her advice and support. We are also grateful to Dr Margaret Quinton and Ian MacMillan for statistical advice. The results of the experiment reported here are submitted as part of a Master's Thesis to the Faculty of Animal and Poultry Science, University of Guelph, Ontario, Canada.