Study On The Quality Of Boar Spermatozoa After Freeze-Thawing In Extender Supplemented With Different Antioxidants

The aim of this study is to examine the effect of addition of different antidants onquality parameters of frozen-thawed boar semen, membrane lipid peroxidation and theability of in vitro embryo production. With holding the penis to obtain pig semen asmaterial, this text carried on the experment of the boar frozen, semen that was frozen bythe straw. The research contents have three respects: I The semen was diluted indifferent proportion, removed clear liquid after being concentrated at different speeds,and then diluted the semen with freezing extender, and finally frozert with the differentcapacity straws, measured the quality of semen by biological method after postthaw;ⅡThe frozen semen that was respectively made with the different kinds of extenders,adding NAC, L-cysteine, and NAC plus L-cystein, measured the quality of semen bybiological method after postthaw;ⅢEffects of the additions of NAC, L-cysteine andNAC plus L-cysteine in the freezing extender on the membrane lipid peroxidation weremeasured by biological method. All resnlts of the test are as follows:1,The motility and acrosomal integrity of 800r/m centrifugation is significant higherthan 500 r/m and 1000r/m, while the tail-coiling is significant lower than 500 r/m and1000r/m (P＜0.05). 1000r/m centrifugation, the acrosomal integrity is significant lowerthan 500 r/m and 800r/m, while the tail-coiling is significant higher than 500 r/m and800r/m (P＜0.05). Although different centrifuge can not affect sperm kinematicparameters (P＞0.05), but the results of 800r/m centrifuge is significant better than500r/m and 1000r/m.2,The differences of the thawed sperm motility are not significant with 1:1 and 1:2diluting semen before centrifuge. (P＞0.05). But the acrosomal integrity 1:1 dilutingsemen is significantly higher than that of 1:2 one after freezing (exceed 15 percentagepoints); tail-coiling is lower extremely (percentage points) of 1:1 diluting semen than1:2 one after freezing (P＜0.05). In.relation to the sperm kinematic parameters, only LIN was affected by the different proportion(P＜0.05). From using different straws, after twodifferent proportions dilute, 0.5ml is superior to 0.25ml among of various field indexes,but the difference is not remarkable between the two (P＞0.05).3,The addition of 1mM NAC in sperm extender for freezing significantly increased thepost-thaw rates of sperm motility and acrosomal integrity compared with the controlgroup, decreased the postthaw rate of sperm tail-coiling (P＜0.05). In relation to spermmotion kinetics, only VAP was affected by the presence of NAC in the freezing extender,being significantly higher in spermatozoa frozen in the presence of NAC(P＜0.05). Datafrom in vitro embryo production showed that the addition of NAC in the freezingextender had no significant effect on the rate of cleaved zygotes (P＞0.05).4,The addition of 0.1mg/ml L-cysteine in sperm extender for freezing significantlyincreased the postthaw rates of sperm motility and acrosomal integrity compared withthe control group, decreased the postthaw rate of sperm tail-coiling (P＜0.05). However,L-cysteine did not affect any of the sperm kinematic parameters evaluated (P＞0.05).Data from in vitro embryo production revealed an improvement of cleavage rates whenspermatozoa were frozen in the presence of 0.1mg/ml L-cysteine compared with controlor the 0.2 mg/ml L-cysteine and 0.3 mg/ml L-cysteine groups (P＜0.05).5,The combined addition of NAC and L-cystein in the sperm extender for freezingsignificantly increased the postthaw rates of sperm motility and acrosomal integritycompared with the control group, decreased the postthaw rate of sperm tail-coiling(P＜0.05). In relation to the sperm kinematic parameters, VAP, ALH, and BCF werehigher and LIN lower in thaw spermatozoa frozen in the presence of NAC plusL-cystein compared with controls (P＜0.05). Data from in vitro embryo productionshowed, when compared with controls, a significantly higher proportion of zygotes(P＜0.05).6,The presence of L-cystein in the freezing extender significantly decreased the level ofmembrane lipid peroxidation (P＜0.05), while the membrane lipid peroxidation wasunaffected by the presence of NAC, NAC plus L-cystein in the freezing extender(P＞0.05).