Effects of different thawing methods on post-thawed motility of cryopreserved cow semen

Sixty frozen bovine semen straws (0.25 mL) collected from five Holstein breeding bulls are thawed to determined the effects of different thawing temperature and times on properties of bull semen.The results show that:(1) With the increasing of thawing temperature,the proportion of motile spermatozoa,the proportion of acrosomal integrity,the motible length get improved significantly( P 0.05).Abnormal spermatozoa rate decreased significantly with the increasing of thawing temperature ( P 0.05).(2) The percent of progressive spermatozoa thawed in 37 ℃ or 75 ℃ is higher with the increasing of thawing time,but the percent of progressive spermatozoa is no relation to thawing time.(3) There is no relation among thawing time and the proportion of motile spormatozoa,the proportion of acrosomal integrity,the motible length.It is suggested to thaw at 75 ℃ for 2~6 seconds in practice.