Effects Of Dietary Zinc On The Reproductive Performance Of Male Broiler Breeder

Three experiments were conducted to study the effects of dietary zinc on the reproductive performance of male AA broiler breeder.Experiment one studied the effects of dietary zinc on the body weight,sex maturity, development of testes of male broiler cocokerels.There are six treatments with different dietary supplement level of zinc(0, 30, 60, 90, 120 and 150mg/kg respectively).90 15-week-old male AA broiler cockerels with similar body weight (2147±113g) were divided into 6 treatments randomly. supplemented to basal diet. Each treatment was replicated three times (5 cockerels per replicate), and the trial lasted 10 weeks. The results indicated that the dietary zinc level influenced significantly the 25 weeks body weight (P < 0.05), testes weight (P< 0.01), testes bulk (P<0.01) and testicular index (P< 0. 01) with no significant influence on the beard size (P>0. 05). The body weight (R~2=0.889, P=0.037), testes weight (R~2=0.905, P=0.029), testes bulk (R~2=0. 904, P=0. 030), testicular index (R~2=0. 915, P=0. 025) and diameter of interstitial cell (R~2=0.907, P=0.029) were increased quadratic . The body weight was positive correlated (r~1 = 0. 950**, r~2==0. 937**) with the weight and bulk of testes. The size of beard also was positive correlated (r~1 = 0. 876*, r~2=0. 888*) with the weight and bulk of testicle. The optimum dietary supplement of zinc was 75—85mg/kg.Experiment two investigated the effects of dietary supplement level of zinc on the sperm quality and serum biochemical index of male broiler breeder. There are six treatments with different dietary supplement level of zinc (0, 30, 60, 90, 120 and 150mg/kg respectively).30 15-week-old male AA broiler breeder with similar weight were divided into 6 groups randomly. Each treatment was 5 birds caged individually, and the trial lasted from 15 weeks to 32 weeks. Every week from 29 weeks to 32 weeks, the sperm quality and serum hormones of each bird was checked. The results indicated that the effects of zinc supplement level on sperm density (P< 0. 01), sperm activity (P< 0. 05), sperm abnormal rate (P<0. 05) , serum AKP activity (P < 0.05) , zinc concentration of serum (P < 0.05), Testosterone concentration of serum (P < 0.05), and Luteinizing hormone concentration of serum (P < 0.05) were significant. The sperm density (R~2=0.940, P=0.015), sperm activity (R~2=0.883, P=0.040), sperm abnormal rate (R~2=0. 950, P=0.011) and Luteinizing hormone concentration...