Effects OFD-sodium Erythorbate And Lysozyme On Boar Semen Normal Temperature Preservation

Preserving the semen at normal temperature is a key technology in the process of artificial insemination of pigs.During the conventional preservation of semen at normal temperature,reactive oxygen species(ROS)began to accumulate in semen with the prolongation of storage time.The special membrane structure makes pig sperm more susceptible to oxidative damage of free radicals and eventually leads to the decrease of sperm motility,the damage of acrosome or even lossing the fertility.In addition,the bacteria and some pathogenic microorganisms of semen will not only directly compete nutrients with sperm,but its metabolic activity will also induce different degrees of damage to sperm,resulting in the decrease of semen quality,affecting the effect of artificial insemination.This experiment investigates the effect ofD-sodium erythorbate and lysozyme on the preservation of boarsemen at normal temperature,and comprehensively analysises and screens the optimum fortified concentration of two drugs,through measuring the sperm motility,plasma membrane integrity,acrosome integrity,total antioxidant capacity(T-AOC),malondialdehyde content,ROS level,sperm motility and semen count.The aim of this study is to provide reference for the improvement of dilution powder which was used to preserve porcine semen at normal temperature.The following are the main results of this study:1.Different concentrations(0.002,0.004,0.006,0.008,0.010 mg/mL)of D-sodium erythorbate were added to the basic extender powder preserveing porcine semen at normal temperature can improve the semen preservation effect with varying degrees.By increasing the concentration of D-sodium erythorbate,the effect of semen preservation was increased at first and then decreased.When the concentration of D-sodium erythorbate was 0.006 mg/mL,the semen could be preserved 5 days,and the sperm motility,plasma membrane integrity,acrosome integrity and the total antioxidant capacity(T-AOC)were significantly higher than other groups(P<0.05),while the content of malondialdehyde(MDA)and reactive oxygen species(ROS)were significantly lower than other groups.On the third day,sperm motility parameters was the best in the group of 0.006mg/mL and significantly higher than control and the low-concentration group(0.002mg/mL).When the concentration was 0.008mg/mL,the quality of semen was better than control(P<0.05),but worse than the group at 0.006 mg/mL.Thus,when add 0.006 mg/mL concentration of D-sodium erythorbate,the preservation of semen was the best.2.Adding different concentrations of lysozyme(0.5,1.0,1.5,2.0,2.5mg/mL)in boar semen basic extender can improve the preserving effect of semen at normal temperature.The sperm motility saving daily,plasma membrane integrity and acrosome integrity were significantly higher than other groups when lysozyme was added with the concentration of 2.0 mg/mL(P<0.05).The number of bacteria in the semen of the same day decreased with the increase of lysozyme concentration on the first day,the third day and the fifth day of storage,and it was significantly different among groups on the fifth day.When the concentration of lysozyme was 2.0 mg/mL,the bacterial content in semen was significantly lower than the other groups(P<0.05).On the third day of storage,when the concentration of lysozyme was 2.0 mg/mL,VSL?VAP and ALH were significantly higher than control(P<0.05),but CMS and BCF were significantly lower than control(P<0.05),with no significantly difference among other groups.On the whole,the concentration of 2.0 mg/mL was the optimum concentration of lysozyme.3.Adding of 0.006 mg/mL D-sodium erythorbate and 1.5 mg/mL lysozyme to the boarsemenbasicextender could significantly enhance the sperm motility and plasma membrane integrity of porcine sperm,and the effect was significantly better than control group and two drugs added alone(P<0.05).In summary,D-sodium erythorbate and lysozyme have a certain effect on porcine semen preservation at normal temperature,and they can effectively protect the sperm performance and improve the quality of semen preservation.The optimum concentration was 0.006 mg/mL and 2.0 mg/mL when the two drugs added respectively,and the optimum concentration of the combination was 0.006 mg/mL D-sodium erythorbate and 1.5 mg/mL lysozyme.