The effects of body weight, dietary fat. and feed withdrawal rate on the performance of broiler breeders

This research was conducted to determine how different dietary and management systems might benefit hatching egg production for flocks with pullets having different BW. The heavy BW pullets produced 3 more eggs than the light BW group before peak because the heavy BW breeder group produced the first egg and reached 50% production 4 to 5 d earlier. However, the light BW breeders produced an equal number of eggs and gained more weight with a higher percentage of carcass crude protein compared with the heavy and medium BW breeders during the experimental period from 20 to 65 wk of age. Feeding high-fat diets to all BW groups of breeders during the 20- to 65-wk period resulted in more weight gain, larger eggs, and 2.5% more carcass fat than feeding low-fat diets, although the breeders were fed equal calories and amino acids each day. Breeders provided a weekly slow feed withdrawal program after peak production with feed being reduced by 0.16 g/d per breeder gained more weight and produced heavier eggs from 30 to 65 wk of age compared with breeders on a faster feed withdrawal program. The breeders provided the faster feed withdrawal program had feed reduced by 0.64 g/d per breeder for wk 1, 0.33 g/d per breeder for wk 2 and 3, and 0.16 g/d per breeder thereafter. The feed withdrawal programs were stopped when breeders were fed 396 kcal of ME/d per hen. The breeder hens that had feed reduced at a faster rate consumed 5.7 g less feed per egg.