Effects of ad libitum and restricted feeding on semen quantity and quality, body composition, and blood chemistry of caged broiler breeder males

One hundred eighty, 16-wk-old, caged broiler breeder males were randomly assigned to one of three feeding treatments: 1) restricted feeding (RES), breeder-recommended levels minus 25%; 2) control feeding (CON), breeder-recommended levels; 3) full-fed (FF), ad libitum feeding. Each group received the same corn-soybean diet, with 15.5% CP and 2,878 kcal ME/kg feed. The males were ejaculated twice weekly, and BW, semen characteristics, hematocrits (HCT), and serum testosterone (T) were determined every 4 wk. At 17, 35, and 56 wk of age males were killed for body composition determination of percentages of protein, moisture, and fat. The FF males were heavier throughout the experiment than either CON or RES males. The FF group had a higher percentage of males in semen production than CON, which had a higher percentage of males in production than RES. Males of the FF group produced more semen with a higher spermatozoa concentration (SC) than CON, which males had higher spermatozoan concentrations than RES. The FF males had a higher level of T overall than CON or RES males. Hematocrits of FF were higher than those of CON birds, which were higher than those of RES birds. Body compositions were not significantly different among treatments at 17 wk; however, at 35 and 56 wk, FF males had a higher percentage of fat and a lower percentage of protein than birds in the other two groups. Significant positive correlations were found between body fat and the variables HCT, BW, semen weight (SW), and SC. Body weight was positively correlated with SW, and T was correlated with HCT.