title: Raised environmental temperature and food rationing as means of restricting growth of the replacement pullet.
abstract: 1. Four rearing temperature regimes (15, 20, 25, 30 degrees C) and three feeding schedules (ad libitum, restricting to the ad libitum intake of the 12th week and feeding 70% of this rate) were carried out with layer replacement pullets to 170 d of age. From this age, during lay, birds were kept at either 21 degrees C or on a 24-h cycle of 21 for 18 h and 28 degrees C for the 6 h before lights out. Both a white and a brown egg-laying strain were used. 2. Body weight at 169 d of age varied from, on average, 1409 g (15 degrees C, ad libitum) to 943 g (30 degrees C, 70% schedule) for the white strain and 1947 to 1250 g for the same treatments respectively for the brown strain. Sexual maturity was considerably delayed by the 70% feeding schedule, only slightly by rearing at 30 degrees C. 3. Rearing at 30 degrees C tended to depress subsequent egg output. The 70% feeding schedule at least maintained egg output compared with birds fed ad libitum in rearing. 4. There was a highly significant effect of temperature treatment during lay on food intake. The reduction in food intake due to the 21-28 degrees C cycle, however, appeared small.
mesh_terms: D000818:Animals; D001835:Body Weight; D002645:Chickens / Q000254:growth & development* / Q000502:physiology; D004032:Diet; D005260:Female; D009026:Mortality; D010058:Oviposition; D012741:Sexual Maturation; D013696:Temperature