Study on Effect of Different Thawing Temperature and Time on Activity of Frozen Semen Straws in Beef Cattle

Objective Seek for optimum thawed temperature and time of semen in beef cattle.Method Fifty-four frozen bovine semen straws were thawed under different thawing temperature and times to determine the semen quality after thawing.Result With the increasing of thawing temperature(40～75 ℃)and the rate of motile spermatozoa increased obviously,the abnormal spermatozoa rate first increased and then decreased significantly.But thawing at high temperature(90 ℃),the rate of motile spermatozoa was lower than that thawed at 40 ℃～75 ℃ significantly(P0.05)and the abnormal spermatozoa rate was higher than that thawed at 75 ℃ significantly(P0.05).Under low temperature(40、75 ℃),with the prolonging of thawing time,the rate of motile spermatozoa increased,but the difference was not significantly.Thawing under high temperature(90 ℃),the rate of motile spermatozoa related to thawing time obviously,the longer the time was,the lower the rate of motile spermatozoa was.There is no relation between thawing time and the rate of motile spermatozoa.Conclusion The suitable thawing temperature and times should be selected according to the practice instance in production and it was suggested to be thawed at 75 ℃ for 3～5 seconds.