圈养黑熊精液的冷冻保存

将采自23 头成年圈养黑熊的精液,分别用3 种稀释液(Ⅰ:Tris - 乳- 果- 卵;Ⅱ:柠- 葡- 蔗- 卵;Ⅲ:Tris - 柠- 果- 葡- 卵)稀释并在4℃ 下保存,通过检测精液在不同稀释液稀释条件下的保存时间,筛选出最适稀释液用于精液的冷冻保存;从精液解冻后精子的活率、活力、畸形率、顶体完整率4 个指标,分别从3种冷冻保护剂(甘油3%、3.5% 、4% )、两种冷冻方法(两步冷冻法和自动冷冻法)两个方面进行了比较试验。结果表明:精子活力在0.3 以上时,稀释液Ⅲ保存时间为175.42 ± 3.04 h,显著高于稀释液Ⅰ和稀释液Ⅱ(P ﹤0.01),稀释液Ⅱ保存时间也明显高于稀释液Ⅰ (P ﹤0.01);含3.5% 甘油浓度的稀释液解冻后精子活率(41.75 ± 3.46% )、活力(32.63 ±5.27% )和顶体完整率(85.62 ± 4.58% )显著高于其他两组(P ﹤0.01),并且精子畸形率(29.32 ± 8.22% )明显低于其他两组(35.95 ± 8.04% ,36.07 ±7.72% )(P ﹤0.01);采用自动冷冻法冷冻保存圈养黑熊精液,解冻后精子活率、活力和顶体完整率分别为41.75 ±3.46% 、32.63 ± 5.27%和85.62 ±4.58% ,都明显高于两步冷冻法(P ﹤0.01);解冻后畸形率为29.32 ± 8.22% ,明显低于两步冷冻法(P ﹤0.01)。

Cryopreservation of the captive black bear (Ursus thibetanus) semen

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).