Optimization Of Cryopreservation Extender Of Donkey Semen

At present,in order to preserve excellent breeding animals,make breeding no longer subject to regional restrictions,and improve the utilization rate of breeding animals,semen preservation technology of many animals has become mature.For example,semen preservation of cattle has been used in production for many years.However,equine animals,especially donkeys,still have a lot of room for progress.The effects of different antioxidants（Resveratrol,Mn Cl₂,Zn SO₄,Na₂Se O₃）on semen cryopreservation of donkey were studied in order to lay a foundation for semen cryopreservation of equine animals.The results are as follows.1.Objective to compare the effects of three different cryopreservation extender on donkey semen freezing.The results showed that No.1（water skimmed milk lactose glucose sodium citrate yolk glycerin）was better than the other two（No.2 and No.3）,and the sperm motility after thawing（36.04±0.16）was significantly higher than the other two（28.97±1.99 and 27.76±0.86,respectively）（P<0.05）.2.The effects of different freezing rates（liquid nitrogen fumigation height of2cm,3cm and 4cm）on semen freezing were compared.The results showed that the freezing effect was the best when the fumigation height was 3cm,and the average activity（36.04±0.16）was significantly higher than that of 2cm and 4cm（P<0.05）.3.Frozen semen of donkey was made with No.1 frozen solution and fumigation height of 3cm.After thawing,the vitality and conception rate during estrus were 35%and 37.5%respectively.4.The effects of four different concentrations of antioxidants on donkey semen cryopreservation were compared with No.1 cryopreservation solution:（1）Adding resveratrol with different concentrations（0,5,10,20,40,100μM）showed that the freeze effect was the best when res concentration was 40μM.the activity,plasma membrane integrity rate and acrosome integrity rate of resveratrol group were significantly higher than those of control group（P<0.05）,the content of ROS was significantly lower than that of control group（P<0.05）,and the activities of antioxidant enzymes（SOD,CAT,GSH-Px）were significantly higher than those of control group（P<0.05）.（2）The results of adding different concentrations of Mn Cl₂（0,0.1,0.5,2,5,10μM）showed that the freezing effect was the best when the concentration of Mn Cl₂was5μM,and its activity,plasma membrane integrity rate and acrosome integrity rate were significantly higher than those of the control group（P<0.05）,and the enzyme activities of SOD and CAT were significantly higher than those of the control group（P<0.05）.（3）The results of adding different concentrations of Zn SO₄（0,0.5,1,2,5,10μM）showed that when the concentration was 5μM,the freezing effect was the best,the acrosome integrity rate was significantly higher than that of the control group（P<0.05）,and the antioxidant enzyme activities（SOD,CAT,GSH-Px）were significantly higher than that of the control group（P<0.05）.（4）Different concentrations of Na₂Se O₃（0.5,1,2,4,8μg/ml）were added to the control group Sperm motility decreased significantly.