Abstract

The present study has been aimed to determine the positive effect that can be detected by microbial phytase supplementation on some semen parameters in broiler breeder roosters (Hubbard Flex). Thirty roosters, twenty- sex weeks age, were randomly divided into three equal groups. First group (control) fed on the standard provender along the experimental period (10 weeks), while other two groups (T1 & T2) fed on standard provender supplemented with 500 & 1000 FTU/ kg of feed, respectively. Semen ejaculates were obtained artificially from all roosters weekly for ten weeks to evaluate the different parameters of semen included in the present study (sperm concentration, mass & individual sperm motility and percentage of dead & abnormal sperms). At the end of the experiment, Blood samples were obtained from wing vein for estimation of testosterone, LH, and FSH concentrations in blood serum. Then, roosters were sacrificed and the testes and epididymis obtained for histological measurement and histo-physiological study. The result revealed that phytase supplementation in the two treated groups caused a significant increase (P<0.05) in sperm concentration began at the 8^th week and continue progressively to the end of experiment at the 10^th week, as well as a significant increase (P<0.05) in mass sperm motility began at the 6^th week, and individual motility (P<0.05) began at the 9^th week when compared with control group. On other hand the result of T2 group showed a significant increase (P<0.05) when compared with T1 results. At the same time, the result of dead & abnormal sperm showed a significant decrease (P<0.05) in the two treated groups compared with control. On the other hand, serum concentration of sex hormones, revealed a significant increase (P<0.05) in Luetinizing and testosterone hormone concentration in the two treated groups compared with control, while the increment of follicle stimulating hormone concentration didn't reach the significant level (P<0.05) in the comparison between the three groups. Size and weights of testes increased significantly (P<0.05) in both T1 and T2 groups when compared with control.