不同解冻方法对奶牛细管冻精活力的影响

Effect of different thawing methods on post-thaw motility of cow semen in cryopreservation straws

研究探讨了不同解冻方法对0．25mL奶牛细管冻精解冻后的影响，细管冻精分别在5，15，40，75，90℃下不同时间（1～120s）进行解冻操作，通过评定精子冻后活率、顶体完整率、尾膜完整率，筛选出最佳的奶牛细管冻精的解冻方法。结果表明：（1）奶牛细管冻精采用75℃解冻3S，精子的活率最高，解冻效果最好；其次在接近体温40℃解冻20s，效果也较好；在低温5cC和室温15℃解冻，精子活率低于0．3；在90％高温解冻条件下不稳定，不适合生产使用；（2）90℃解冻精子的顶体完整率、尾膜完整率明显低于40℃和75℃，差异显著（P〈0．05），但是精子畸形率却高于40℃与75℃的处理组（P〈0．05），而后两者间差异不显著（P〉0．05）；（3）不同解冻温度解冻后精子在37℃时保持有效存活时间存在较大差异，表现为：40℃〉75℃〉90％。因此，在生产实践中对奶牛细管冻精进行解冻时，可根据具体情况选用适合的解冻方法。若解冻后立即输精的，建议采用75℃下3s解冻；解冻后不能立即输精的，为了使精子在较长时间内保持活力，宜采用4℃下20s解冻。

The study compared the effects of different thawing temperatures （5, 15, 40, 75, 90℃ ） and times（ 1- 120 s） on properties of post-thaw cow semen by detecting frozen-thawed semen motility, acrosome integrity and tail membrane integrity. The results showed that motile spermatozoa rate of frozen semen thawed at 75℃ for 3 s was the highest. A dmilar result was observed under thawing at 40% for 20 s. Under 5℃ and 15℃ thaw sperm motility was lower. Sperms defrosted at 90℃, the acrosome integrity and tail membrane integrity were significantly lower than those at 40℃ （P 〈0. 05） and 75℃ （P 〈0. 01 ）, and the sperm deformity rate was significantly higher than that trea- ted at 40℃ and 75℃ （P 〈0.05）. With the increasing of thawing temperature, the sperm effective survival time at 37℃ showed significant difference as 40℃ 〉 75℃ 〉 90℃. In conclusion, it was recommended that the frozen semen thawing at 75℃ for 3 s could be used for artificial insemination immediately. When a large number of cows need to be inseminated or thawed semen could not be inseminated immediately, in order to keep the sperm vitality for a lon- ger time, the frozen semen thawing at 40℃ for 20 s would be suitable.