Responses of sexually-maturing pullets to self-selection feeding under different temperature and lighting regimens.
1. Pullets allowed to self-select nutrients from a protein concentrate and either a separate complete diet or cereal-based, energy-rich mixture showed preferences for protein and energy which varied in relation to the time of their onset of lay. 2. The selected protein:metabolisable energy (ME) intake ratio increased from 14 g protein per MJ of ME 2 to 3 weeks before sexual maturity to approximately 19 g protein per MJ of ME at and after sexual maturity. 3. This response to self-selection feeding was consistent with different temperatures, lighting patterns and dietary manipulations. 4. Egg mass output was improved by self-selection feeding at hot (25 degrees to 35 degrees C) temperatures in experiments 1 and 2 and at ambient temperatures in experiment 3. No beneficial response in egg mass from self-selection feeding was observed at cold (6 degrees to 16 degrees C) temperatures in experiment 1. 5. Providing 2 h of additional light during the dark (cool) part of the day, with or without 2 h of darkness in the middle of the extended light (hot) period, had no effect on the egg mass output of pullets at hot (25 degrees to 35 degrees C) temperatures.
Scott
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TA
Department of Animal Husbandry, University of Sydney, Camden, New South Wales, Australia.
Balnave
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D
D000818:Animals; D002645:Chickens / Q000502:physiology*; D004032:Diet; D004435:Eating; D005247:Feeding Behavior; D005260:Female; D008027:Light; D010058:Oviposition; D012741:Sexual Maturation; D013696:Temperature; D015430:Weight Gain