Effects of feeding regimen during early development on body composition, gastrointestinal tract size, and semen quality of broiler breeder cockerels after maturation.

Broiler breeder males were randomly assigned at 3 wk of age to one of three feeding treatments: 1) limited amount daily feeding (LD), 2) skip-a-day feeding (SAD), or 3) limited time feeding (LT). The same diet (16% CP and 3,011 kcal ME/kg) was provided from 3 to 22 wk of age to each treatment. The amount of feed or feeding time was adjusted to maintain recommended BW across treatments. At 22 and 34 wk of age, testes and gastrointestinal (GI) weights and carcass compositions were obtained. From 22 to 34 wk, birds were individually caged and fed ad libitum a breeder diet (15.5% CP and 2,878 kcal ME/kg). Males were ejaculated twice weekly, and BW and semen characteristics were recorded weekly. No significant differences existed among treatments for BW or body composition at 22 wk, but SAD birds had heavier crops and lighter gizzard weights than either LD or LT birds. Sexual maturity occurred 10 days earlier in the LD group than the SAD group; however, the LD group had reduced semen yields and spermatozoa concentrations compared to those in the SAD group. At 34 wk, there were no significant differences among body or GI weights, body moisture, or ash among the treatment groups. Birds in the LD group had heavier livers, greater amounts of body fat, smaller testes, and reduced body protein than those in the other treatments.