Due to differences in body size and growth potential, it is recommended that broiler breederpullets and males be reared separately, instead of traditional commingling, where they are grown
together. The objectives were to: (1) compare body composition, growth, and reproductive
performance of broiler breeder pullets when reared sex-separately or commingled and fed an
increased or standard feed allowance as recommended by primary breeders; and (2) examine
sex-separate and commingling’s impact on body composition, testicular development, growth,
and reproductive performance of broiler breeder males. Commingling had little impact upon
pullet growth yet enhanced late egg production while improved feather coverage of sex-separate
pullets increased fertility later in life. Feeding pullets a standard allowance improved uniformity
and egg production whereas increasing allowance led to heavier pullets with enhanced early egg
production. Later in life, commingled males had poor uniformity and fertility whereas sex-
separate males had improved uniformity, testicular development, and fertility.
