Dietary Effects on Body Composition and Subsequent Production Characteristics in Broiler Breeder Hens

Abstract

Broiler breeder pullets were fed either a broiler starter (23% CP, 3,133 kcal per kg) or pullet grower (15.5% CP, 2,885 kcal per kg) diet from 2 to 18 wk of age. Feed allocations were adjusted to equalize energy intake (kcal per day). Protein intake, however, was greater for pullets fed the starter diet versus those fed the grower diet A sample of pullets of similar BW from each treatment was killed at 13 and 18 wk of age. The starter diet resulted in a significant increase in the weight of the tibia and the associated muscles (total drumstick) and of the Pectoralis major (breast) muscle and a significant decrease in the size of the abdominal fat pad at both ages. During the prelay period (18 to 25 wk), half the pullets in each pullet treatment were fed either the pullet grower (LP) or broiler starter (HP) diet There were no significant effects of protein intake during the rearing or prelay periods on the aforementioned carcass parameters at 25 wk of age. The HP treatment resulted in a significant increase in hen-day production from 28 to 32 and from 32 to 36 wk of age. The LP treatment resulted in a nonsignificant increase in BW at 27 wk (P<.064) and in the number of double-yolked eggs from 32 to 36 wk (P<.096) relative to the HP treatment. Egg size was also increased nonsignificantly (P<.067) from 28 to 32 wk by the LP treatment relative to the HP treatment.