Daily Energy Allotments and Performance of Broiler Breeders

Arbor Acres broiler breeder hens, 21 to 61 wk of age, were given the daily ME level recommended by the primary breeder for their age and level of production (100% AA) or were given 94 or 88% of that amount. The reduction in daily energy allotment had no effect on age at 50% or age at peak production, but there was a highly significant linear decrease in the eggs per hen from 165 +/- 2.8 in hens given 100% AA to 149 +/- 3.2 and 141 +/- 3.8 in hens given 94 and 88% AA. The percentage of nonlaying hens between 44 and 60 wk of age was substantially increased as daily energy allotment was reduced. The percentage settable eggs was significantly lower in the 100% AA group, but no differences in fertility or hatchability were seen. Chicks per hen fell from 123 +/- 2.4 to 116 +/- 2.4 to 102 +/- 2.6 as energy allotment was progressively reduced. Dietary energy allotment had no effect on egg weight, shell weight, shell characteristics, or proportion of albumen and yolk. Chick weight was unaffected but chicks' liver weight increased with increasing dam energy intake. Percentage lipid in hens' carcasses increased with increasing energy intake and percentage protein and percentage ash decreased.