Two experiments were conducted to determine that variation in broiler P utilization is due to breeder age and egg storage time. Experiment 1 was conducted with chicks hatched from eggs laid by Ross × Ross 308 breeders (27 vs. 61 wk old) and stored for 0 or 10 d. The age of breeders had significant effects (P < 0.05) on 0 to 16 d chick growth (379 ± 18 vs. 308 ± 19 for 27-and 61-wk-old breeders, respectively). The longer egg storage time of chicks from older breeders resulted in higher P rickets

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... scores and incidence, but longer egg storage time of chicks from younger breeders resulted in lower P rickets score and incidence (significant interaction, P = 0.0455). The longer egg storage time of chicks from older breeders resulted in lower bone ash (%), and the longer