Effect of Strain, Feed Allocation Program, and Age at Photostimulation on Reproductive Development and Carcass Characteristics of Broiler Breeder Hens

ABSTRACT A study was conducted with broiler breeder pullets to investigate the effects of strain, age at photostimulation (PS), and release from feed restriction at PS on age, BW, ovarian morphology, and carcass char-acteristics at sexual maturity (point of initiation of lay). Sixty birds of each of 4 strains were used. The 4 types represented a classic strain (A), 2 high-yield strains (B, C), and a roaster strain (D). Photostimulation (8L:16D to 14L:10D) was applied at 2 different ages (21 and 24 wk) to 30 birds of each strain type. Within each of the PS periods, 15 birds of each strain were fed ad libitum (F), and the remaining 15 were feed-restricted (R) following a common feeding schedule. On the day that each bird had its first oviposition, its feed was withdrawn. It was euthanized the following morning by cervical dislocation and organs were collected. Of the 3 main effects, feeding (Key words: broiler breeder, large yellow follicle, ovary, ultrasound