الفهرس | Only 14 pages are availabe for public view |
Abstract This study took place at Animal Production Experimental Station, Mehallet Mousa, belonging to the Animal Production Research Instiute, Agricultural Research Center, Ministry of Agricultural, in cooperation with Animal Production Department, Faculty of Agriculture, Mansoura University, during the period from August 2003 to May 2004. A total 15 buffalo bulls was used in this study, 7 culled buffalo bulls were taken from the flock of the station and were considered as a subfertile group. Eight normal buffalo bulls with good semen quality were chosen as a fertile group. The effect of rbst was conducted throughout three experimental periods pretreatment (5 weeks), treatment (7 weeks) and posttreatment (7 weeks) periods. During treatment period, bulls in both groups were subcutanously injected with a dose of 400 mg rbst/bull given once every 14 days for 4 injections. Results could be summerized as the following: 1 Percentages of sperm mass motility, live, abnormal, curled and intact acrosome spermatozoa were significantly higher during treatment than posttreatment by about 11.6, 14.2, 13.7, 7.8 and 6.6%, respectively. 2Overall means of all testicular measures were not affected by treatment period, except the testicular thickness, was significantly (P<0.01) higher by about 20% pretreatment than post treatment. 3Overall means of concentration of fructose were nearly similar in fertile and subfertile bulls (679.6 vs. 678.0 mg/dl) and were slightly higher prethan posttreatment period (689.5 vs.622.4 mg/dl). 4 Overall mean of testosterone concentration were significantly (p<0.01) higher in fertile than subfertile buffalo bulls (0.613 vs. 0.288 ng\ml). 5 Overall mean of testosterone concentration was significantly (p<0.05) higher during posttreatment period than pre and treatment periods by about 53.3,53.7%respectively. On the basis of the obtained data, marked differences were found between fertile and subfertile buffalo bulls concerning semen quality, testosterone concentration and morphohistometric characteristics of the sex organs, the accessory glands and thyroid gland. However, histogenesis of the pituitary and adrenal glands were nearly similar in both groups. On the other hand, treatment with rbst had no marked effects on semen quality of buffalo bulls. More research studies needed to improve the reproductive performance of buffalo bulls by using rbst in different doses and different intervals of injection. |