关键词: 圈养黑熊, 精液, 冷冻保存

Abstract: Semen was collected from 23 adult captive black bears. The ejaculates were diluted in three different extenders (Ⅰ:Tris-lactose-fructose-yolk,Ⅱ:Citric acid-glucosesucrose-yolk,Ⅲ:Tris-citric acid-fructose-glucose-yolk ). Thereafter, the diluted semen was stored at 4℃ . In the first part of this study,we evaluated the preservation time until sperm mobility rate declined to 0.3 in the three extenders. In experiment 2,we compared three different concentrations of glycerin in the cryoprotectants on frozen-thawed sperm viability,mobility,abnormality and intact acrosome rate of sperm. Finally, we compared computerized slow-stage and static liquid nitrogen vapour freezing methods. The results were as follow:When the mobility rate of sperm is over 0.3,the preservation time (175.42 ±3.04 h) in extender Ⅲ was longer than in extenders Ⅰ and Ⅱ (P < 0. 01),the preservation time in extender Ⅱ was longer than in extender Ⅰ (P <0.01). When using
3.5% glycerin as a cryoprotectant in extender Ⅲ,frozen-thawed sperm viability (41.75 ±3.46% ),mobility (32.63 ±5.27% ) and intact acrosome (85.62 ±4.58% ) rate of sperm were significantly higher from the other groups (P <0.01), and the abnormity (29.32 ± 8.22% ) rate of sperm was significantly lower than in the other groups (35.95 ± 8.04% , 36.07 ±7.72% ) (P ﹤ 0.01). When using automation of cryoapplication,frozen-thawed sperm viability,mobility and intact acrosome rate of sperm were significantly higher than ambi-step cryoapplication (P < 0.01),and abnormity rate of sperm was significantly lower than ambi-step cryoapplication (P < 0.01).

Key words: Black bear (Ursus thibetanus), Forzen reservation, Semen