Acrosin Activity Analysis of Silkworm Sperm and Artificial Insemination With Cryopreservation Sperm

Using the improved Kennedy's method,the acrosin activity of silkworm sperm was determined,and the optium condition for determining the acrosin activity of silkworm sperm was obtained.The incubation temperature is 25 ℃ and incubation time is 4 h.The acrosin activity declined with the time passing when the sperm was preserved at 4 ℃,the determination of acrosin activity should been finished within 15 h.Although the acrosin activity of freezed sperm was dropped with the freezing time passing,the change trends of it were distinct among different freezing modes.When the sperm was preserved at-80 ℃,the acrosin activity was declined in linearity and dropped 61% after 120 d.When the sperm was preserved in liquid nitrogen,the acrosin activity at 30 d is 58 percent of the beginning's,but it dropped unobviously within the following months.Besides,the acrosin activity was related to the total laying eggs number and the fertility rate of artificial inserminated sperm.The lower the acrosin activity is,the less the laying eggs number and the lower the fertility rate are.This suggested that the acrosin activity could reflect the quality of sperm to a certain extent.