INFLUENCE OF TEMPERATURE DURING GROWTH ON RESPONSES OF HENS TO HIGH OR LOW-TEMPERATURES DURING LAY

1. Commercial pullets were grown at cool (10 degrees-20 degrees C) or hot (25 degrees-35 degrees C) temperatures to similar bodyweights at 1 8 weeks of age. Between 18 and 50 weeks the birds were either kept at the same temperatures as during growth or transferred to the alternate temperature. 2. Birds kept at the cool temperatures throughout life a te most food and gave the best production during lay. Minimum food int ake and poorest performance were obtained with birds kept at the hot t emperatures throughout life. 3. Performance in the hot environment dur ing lay was improved by rearing birds in the cool. environment, the re sponse being related to an increased food intake. Food intake in the c ool environment during lay was reduced, with only minor effects on per formance, in birds which had been reared in the hot environment. 4. Th e results of the present study show that production responses during l ay are affected by the temperatures experienced by hens during both gr owth and lay.