The effect of feeding programs on reproductive traits and selected blood chemistries of caged broiler breeder males

The effects of five different feeding levels [136, 125, 113, 102, and 91 g/male/day of a 13.1% crude protein (CP), 3167 kcal metabolizable energy (ME)/kg feed] were evaluated on the reproductive traits of caged adult broiler breeder males from 30 to 60 weeks of age. Individual body weights, semen volume, sperm cells per ejaculate, and fertilizing ability were measured at 30, 40, 50, and 60 weeks of age. To assist in measuring the effect of feed restriction on metabolism during these periods, average hematocrits, plasma cholesterol, total protein, and uric acid levels were analyzed. Significant (P less than .05) reductions were observed in average body weights, semen volume, sperm cell numbers per ejaculate, testicular weights, and hematocrits with feed restriction at the 91-g compared to the 136-g feeding level. At 40 weeks of age, the percent of males producing semen was significantly reduced for the 102-and 91-g compared to the 136-g feeding level. Average plasma cholesterol levels were significantly increased at the 91-g compared to the 136-g feeding level, but little effect was observed in plasma total protein and uric acid levels. Correlation coefficients were negative for plasma cholesterol to body weights, sperm numbers per ejaculate, and testicular weights but positive for body weights to hematocrits and testicular weights.