The Study Of Semen Quality And Preservation Of Black Bear

The experiments were involved electro-ejaculation from 35 healthy black bears which were 4 years to 13 years old. During that time, bears were ejaculated 141 times which held 87.58 percent to the total number. The average body weight of the black bears was 125Kg. The ejaculation volume of male black bear was 2.42ml. Sperm motility was 0.21, after diluted sperm motility was 0.75. The rate of abnormal sperm was 21.4%. The integrity rate of acrosome was 89.1%, the sperm concentration was 6.64million, pH was 6.6 and look on subacidity. The semen of black bear was ivory or light grey, with a little offensive smell of fish, sperm head was long oval-shape.The ejaculation volume in June, July, August and September were 0.38 , 2.15, 3.63 and 1.97 respectively (2.15 vs 1.97, P>0.05; another P<0.05); Sperm motility were 0.12, 0.21, 0.32 and 0..23 (0.32 vs 0.23, P>0.05; another P<0.05); the sperm concentration were 5.91, 6.19, 7.94 and 6.32 (5.91 vs 6.19, 6.19 vs 6.32, P>0.05; another P<0.05); the rate of abnormal sperm were 26. 1, 21.2, 18.6 and 21.5% (21.2 vs 21.5, P>0.05; another P<0.05).Semen which was diluted and its motility was 0.8, on the condition of low temperature (4 ), were preserved through 4hours, 24hours, 48hours, 72hours, 96hours, 120hours and 144hours,and the average sperm motility were 0.69 . 0.58,0.42 and 0.26.respectively (0.26 vs 0.15, P>0.05; another P<0.05).After dilution of semen with extender containing different concentration of glycerin( 1-10%), the diluted semen was frozen. The sperm motility after thawing were 0.17, 0.33, 0.49, 0.52, 0.42, 0.21, Very slow movement, Individual movement, Immobility, Immobility, respectively (0.17 vs 0.21, 0.33 vs 0.21, 0.49 vs 0.42, P>0.05; another P<0.05).After dilution of semen with extender which contain 4% glycerin andequilibrium in a low temperature (4 ) for different time(1~4hours), the sperm motility after thawing were 0.46 , 0.54 , 0.51 and 0.48 respectively (0.46 vs 0.48, 0.54 vs 0.51, 0.51 vs 0.48, P>0.05; another P<0.05). The best time of equilibrium was 2 hours.