INTERRELATIONSHIPS AMONG EGG WEIGHT, HATCHABILITY, CHICK WEIGHT, POSTHATCH PERFORMANCE AND REARING METHOD IN BROILER BREEDERS

Hatching eggs, from 2 broiler lines, categorised into 4 groups. viz, u p to 60g (A), 60.1-65g(B), 65.1-70g (C) and above 70g (D), were incuba ted after being stored for 0-9 days at 10-15 degrees C. The hatchlings of each group were reared either separately or in mixed group togethe r with those of other groups to assess their performance till 6 weeks of age. While fertility and per cent hatch weight remained unaffected by egg size, hatchability decreased with increasing egg weight. Correl ation coefficient between egg weight and body weight at all ages of me asurement was positive. Day-old chick weight increased significantly ( P < 0.01) with increase in egg weight. Body weight at 6 weeks was sign ificantly (P < 0.01) lower in group A and was highest in groups C and D. Feed efficiency was comparable for all the groups. Mortality was hi ghest in group A. Rearing of chicks according to body size yielded hig her body weight with low mortality and reduced variation in chick perf ormance among the groups. Length of storage had no effect on the trait s. studied.