Eggs and chicks from broiler breeders of extremely different age

Eggs and broiler chicks originating from breeder flocks having extremes in age (27 vs. 62 wk old) were examined. Eggs from the older flock were heavier and had a greater proportion of yolk and smaller proportions of albumen and shell than those from 27 wk old birds. Yolks of eggs from young breeders and albumen of eggs from old breeders had greater percentage of moisture. Chick and yolk sac weights from old breeders were greater hut yolk sac proportions were not different. Analyses for crude protein and amino acids, as well aa ash and minerals of eggs, chicks, and yolk sacs did not reveals obvious differences in concentrations. Phosphorus in the yolk sac of chicks from young breeders appeared to be tow, indicating that additional supplementation in the first feed may be appropriate.