Studies On Cryopreservation Of Boar Semen

In this study, motility and acrosome integrity of frozen-thawed spermatozoa were used to select the optimum extender for boar semen cryo-preservation, to determine the optimum glycerol concentration, and to discuss the effect of the method of freezing, the thawed temperature and additive on cryo-preservation of boar semen, and the results were as follows:1. Semen motility of boar semen immerged into liquid N₂ directly and fumed over liquid N₂ were not significantly different(P>0.05), but were all better than that frozen using programmable freezing machine(P<0.05). With 0.5ml straws, semen motility of boar semen fumed over liquid N₂ was better than that immerged into liquid N₂ directly(P<0.05). When using the same freezing method, semen motility of boar semen frozen in 0.25ml straw was better than that in 0.5ml straw(P<0.05), and better than that in 5ml straw(P<0.05). When boar semen was fumed over liquid N₂, there were no difference between in 0.25ml straw and in 0.5ml straw(P>0.05).2. Semen motility of boar semen frozen using egg yolk extender was better than that frozen using BTS(P<0.05).3.Motility of frozen-thawed semen were identical when thawed in 40℃ and 50℃ water bathe(P<0.05), but were all better than that thawed in 30℃(P<0.05). When boar semen was frozen in 0.25ml straw, the motility of semen thawed in 40℃ water bathe was better than that in 50℃(P<0.05). Using the same thawed temperature, the motility of boar semen frozen in 0.25ml straw was better than that in 0.5ml straw(P<0.05), and were all better than that in 5ml straw(P<0.05). When thawed temperature was 50℃, there were no significant difference when boar semen were frozen in 0.25ml straw and that in 0.5ml straw(P>0.05).4.When the velocity of centrifugation were 1200rpm, 1800rpm and 2400rpm, motility and acrosome integrity of frozen-thawed semen were all the same(P>0.05).5. When the final glycerol concentration in the extender was 2% and 3%, there were no significant difference in motility of frozen-thawed semen(P>0.05), and they were all better than that when the final glycerol concentration was 4%(P<0.05). When the final glycerol concentration in the extender was 2%,3% and 4%, there were no significant difference in acrosome integrity of frozen-thawed semen(P>0.05) When the final glycerol...