The Effect Of Adding Melatonin To The Diluent On The Cryopreservation Effect Of Cashmere Goat Semen

At present,the artificial insemination rate of goat frozen semen is low.Since the goat sperm plasma membrane is rich in a large amount of unsaturated fatty acids,a large amount of active oxygen is produced by freezing,which causes accumulation of lipid peroxide and damages sperm.In order to avoid different degrees of oxidative damage and quality degradation caused by spermatozoa during freezing and thawing,this study evaluated the effect of adding melatonin on the semen quality and antioxidant capacity of Liaoning cashmere goat sperm after thawing.Different concentrations(0,0.1,1,2,3,4,5 mM)of melatonin were added to the frozen dilution solution for the freezing test.The main results of the study were as follows:First of all,the sperm viability(51.38± 8.73%)with a melatonin concentration of 1mM was significantly higher than that of the control group(35.40± 14.52%)by the sperm analyzer(P < 0.05).and there was no significant difference with the 2 mM group(44.17±10.99%)(P>0.05).The percentage of total motile sperm in the 1 mM group(64.41±13.85%)was significantly higher than that in the control group(41.75± 15.48%)(P <0.05),and the difference from the 2 mM group(52.54± 11.57%)was not significant(P >0.05).The percentage of live sperm in the 1 mM group(83.56% ± 3.14)was significantly higher than that in the control group(73.19% ± 4.31)(P<0.05);the percentage of plasma membrane integrity in the 1 mM group(66.07% ± 2.91)was significantly higher than that in the control group(59.28%±7.87)(P<0.05);the percentage of acrosome integrity in the1 mM group(84.31%±1.63)was significantly higher than that in the control group(65.19%±8.38)(P<0.05);the deformity rate in the 5 mM group(10.69%±2.84))was significantly higher than the control group(7.94% ± 1.43)(P<0.05).Glutathione peroxidase(GPX)activity(6.10±0.93)with melatonin concentration of 2 mM was significantly higher than that of the control group(4.37±0.62)(P<0.05);different concentrations of melatonin were added.At the time of thawing,the difference of sperm lipid peroxide(MDA)activity was not significant(P>0.05).In summary,the addition of 1 mM melatonin to the frozen dilution of goats can improve the quality of semen after thawing;The addition of 2 mM melatonin to the dilution increased the activity of sperm glutathione peroxidase after thawing;the addition of different concentrations of melatonin in the frozen dilution of goat had no effect on the lipid peroxide of the sperm after thawing.