Response of broiler breeders to low-protein diets. 2. Offspring performance.

Broiler breeders were allocated at random to one of four experimental diets containing various levels of CP (16, 14, 12, or 10%), at constant methionine+cystine and lysine levels of .59 and .82%, respectively. Diets were isoenergetic and all birds received the same quantity of feed daily to 64 wk of age. Eggs from birds fed 10 and 12% CP were consistently smaller (P < .01) and in two trials involving breeders at 30 and 52 wk of age this resulted in reduced chick weight at hatching, although no lasting effect was observed on weight of offspring at 48 d. Better feed efficiency (P < .05) was observed from broilers hatched from hens fed lower CP diets. These data suggest that it is possible to reduce the CP intake of broiler breeders while maintaining intake of critical amino acids without adversely affecting offspring performance.