Effects of pullet-stocking density on performance of laying hens.
Effects of cage-stocking density during the rearing period on three commercial strains housed in open and closed rearing and laying houses were examined in two experiments. Stocking densities in Experiment 1 were 311, 259, and 239 cm2 per bird and in Experiment 2 were 311, 259, and 222 cm2 per bird. In the rearing period, greater stocking densities significantly reduced feed intake and 18-wk body weight and increased age at 50% production. In the second experiment, mortality to 20 wk was higher among birds reared at 222 cm2 per bird compared to the less dense treatments. In the laying phase of the experiments, there were no differences among the treatments in number of eggs per bird housed, layer mortality or kilograms of feed consumed per kilograms of egg produced. Final (499 days) body weight of hens reared at 222 cm2 per bird was significantly less than that of those in the other treatment groups. Egg weight of birds reared at 22 cm2 per bird was significantly greater than that of birds reared at 311 cm2 per bird in Experiment 2. Calculated incomes over feed and chick costs were not different among the treatments in either experiment. A less rapid decline in egg production was noted among birds reared at the highest stocking density over the time of the experiment.
Department of Poultry Science, North Carolina State University, Raleigh 27695-7608.
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Carey
D000822:Animal Husbandry; D000818:Animals; D002645:Chickens / Q000502:physiology*; D003441:Crowding / Q000502:physiology*; D005260:Female; D010058:Oviposition; D011156:Population Density