Education and Production

An experiment was conducted to assess how hatching performance is affected by breeder age and egg holding environment during short-term storage. Response variables analyzed were egg weight loss up to 18 d of incubation, viability (hatchability of fertile eggs), embryonic mortality, hatching time, and weight of male and female chicks, at hatching and at the end of incubation. The trials involved a total of 2,250 hatching eggs from each of two commercial broiler breeder flocks of the same strain (Avian) but of different ages (32 to 34 and 48 to 50 wk). Eggs were stored for 0, 1, or 2 d in the egg storage room or in the setter room. The hatching times of the chicks were recorded at 4-h intervals during the period from 478 to 494 h postincubation, and at 514 h, when incubation was terminated and all chicks were removed from the hatcher. In eggs from younger hens, viability was not influenced by preincubation storage; in older hens, viability of eggs not submitted to storage was higher (P < 0.05) by 3 to 6 percentage points than that of stored eggs. Hatching times were not affected by age of the hen, whereas male chicks tended to hatch, on average, about 3 h later than females. Chick weights at hatching and at removal from the hatcher were similar for both sexes, but females experienced a higher (P < 0.05) weight loss in that interval. Eggs incubated on the day of lay tended to hatch, on average, later than stored eggs (especially when compared to eggs submitted to 1 d storage), and produced heavier chicks. (