| Artificial insemination technology has been widely popularized in animal husbandry,and the importance of semen preservation is self-evident.With the prolongation of semen preservation time,a large amount of reactive oxygen species(ROS)could accumulate in the sperm.Excessive ROS could induce the structure and function oxidatively damage in the sperm,thereby affecting the quality of the semen.One method of reducing the sperm oxidative stress is to add exogenous antioxidants to improve the antioxidant capacity of semen in practical production.Studies have shown that angelica polysaccharides(AP),lycium barbarum polysaccharides(LBP)and astragalus polysaccharides(APS)all have strong antioxidant properties.In this experiment,three different low-temperature dilutions of sheep semen were compared.They were "Extender 1 " based on Tris-egg yolk-citric acid-glucose,"Extender 2 " based on skimmed milk powder-soy lecithin-fructose formula,and "Extender 3 " based on Tris-egg yolk-citric acid-fructose.The most suitable diluent was selected for further analyzing.Then different concentrations of AP,LBP and APS were added into the semen extenders,after storage at 4℃ for different times,the sperm viability,motility,ratio of acrosome integrity,ratio of mitochondrial integrity,total antioxidant capacity(T-AOC),superoxide dismutase(SOD)and malondialdehyde(MDA)concentrations in sperm were analyzed.The main results of this research are as follows:1."Extender 3 " should best result among there extenders.The total movement(TM,64.01%),progressive movement(PM,51.36%),percentage of fast exercise(RM,35.6%)at 72 h in "Extender 2 " were significantly higher than the "Extender 1"(P <0.05).After 72 hours of semen preserved,"Extender 3 " had the best preservation effect.TM(54.91%),PM(43.27%),RM(19.73%),and mitochondrial integrity 68.03% in "Extender 3 " were the highest among three groups.The acrosome integrity rate(60.55%)also significantly higher than "Extender 2 "(P <0.05)at 168 h.At 120 h,the T-AOC of "Extender 3 " dilution group(0.764 mmol/mgprot)at 120 h was significantly higher than that of the "Extender 2 "(P <0.05),and the SOD(13.443 U/mgprot)at 120 h was significantly higher than the "Extender 1 "(P <0.05),MDA(11.648 nmol/mgprot)at 120 h was significantly lower than the " Extender 2"(P <0.05).2 The optimum concentration of AP in "Extender 3 " was 2000 mg/L.When sperm is stored at low temperature for 168 hours,most of the sperm indicators are best among different groups.TM(57.63%),PM(46.38%),and RM(21.58%),the acrosome intact rate(54.56%)in group 2000 mg/L AP were higher than control group(P <0.05).The mitochondrial integrity of the 2000 mg/L group was significantly higher than that of the control group(46.36% vs 44.34% P <0.05)when stored for120 h,and the concentration of MDA was also decreased after added AP.3 The optimal concentration of LBP was 200 mg/L.Semen was stored for 168 hours,and the levels of TM,PM,VCL,VAP,and concentration of T-AOC in the 200 and 400 mg/L supplementation groups were higher than control group.The 200 mg/L LBP supplemented group had the best preservation effect,TM(43.33%).PM(30.69%),RM(10.54%)were all higher than other experimental groups,but the difference was not significant(P>0.05).When stored for 120 h,the acrosome integrity rate(67.10%),and the mitochondrial integrity rate(63.70%)in 200 mg/L group were significantly higher than control group(P <0.05).4 Adding APS could improve the motility and acrosome integrity rate of semen.The optimal concentration of APS was 400 mg/L.After storage for 168 hours,the TM(44.7%),PM(34.59%),acrosome integrity rate(61.56%)in 400 mg/L group were significantly higher than control group(P <0.05).However,APS seemed to be detrimental to the integrity of sperm mitochondria.In conclusion,"Extender 3 " was most suitable for sheep semen storage,and2000 mg/L AP,and 200 mg/L LBP were recommended to added in the "Extender 3 " when storage sheep sperm for 168 h at 4℃. |
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