Effect Of Chitosan,Gentamicin And Vitamin C On Quality Of Boar Semen During Normal Temperature Preservation

With the extensive application of pig artificial insemination technology in animal husbandry,semen preservation technology has also developed rapidly.Due to the particularity of the structure of boar sperm,storage of boar semen at room temperature is the most commonly used method.As we all know,bacterial contamination and oxidative stress are two important obstacles to the preservation of boar semen at room temperature.Current research shows that adding appropriate antioxidants to the diluent can effectively prevent the oxidative damage of sperm,thereby improving the quality of semen preserved at room temperature.However,with the banning of antibiotics,new antibiotic replacement strategies have gradually become a research hotspot.Chitosan has a variety of biological functions such as improving animal growth performance,enhancing body immunity,regulating fat metabolism,antibacterial,antibacterial and anti-oxidation.It is considered to be a green additive with broad development prospects,but chitosan is useful in semen preservation.There is little research.Therefore,in order to improve the effect of boar semen storage at room temperature,this study combined with the basis of previous research,adding 0.1 g/L chitosan to the boar semen storage dilution at room temperature to detect sperm motility,plasma membrane integrity,Acrosome integrity,etc.,compared with 0.25 g/L gentamicin and 0.068 g/L vitamin C,and performed 16 S r DNA sequencing analysis to study the anti-oxidant and antibacterial properties of chitosan,with a view to the application of antioxidants in boar semen storage at room temperature provides a theoretical basis.The main results of this study are as follows:1.Add 0.1 g/L chitosan,0.25 g/L gentamicin,and 0.068 g/L vitamin C to boar semen storage dilution at room temperature.After 6 days of preservation at room temperature,the preservation quality of the three groups was significantly higher than that of the control group(P <0.05),and the preservation quality of the diluent added with gentamicin was significantly higher than that of the other groups(P <0.05).The preservation quality of sugar group was significantly higher than that of vitamin C group(P <0.05).The sperm motility,plasma membrane intact rate and acrosome intact rate of the diluent added chitosan group for 6 days reached 61.67%,68.67% and 72.67%,respectively,second only to the gentamicin group,but were significantly higher than the control group.At the same time,the proportion of sperm apoptotic cells in the control group was the highest,the proportion of sperm apoptotic cells in the chitosan group with 0.1 g/L and the vitamin C group with 0.068 g/L was second only to the control group,with 0.25 g/L added The percentage of sperm apoptotic cells in the gentamicin group was the lowest.Therefore,adding 0.1 g/L of chitosan to the diluent can achieve the effect of traditional additives such as gentamicin,and its effective storage time can reach 6 days.2.Add 0.1 g/L chitosan,0.25 g/L gentamicin,and 0.068 g/L vitamin C to boar semen storage diluent at room temperature to evaluate the related antioxidant enzymes and apoptosis of sperm after storage at room temperature for 6 days.It was found that 0.1 g/L chitosan was added to the dilution.The T-AOC activity,GSH activity,SOD activity and CAT activity of sugar and vitamin C were significantly higher than that of the gentamicin group and control group(P < 0.05),and the MDA content and ROS level were significantly lower than that of the gentamicin group And the control group(P < 0.05).There was no significant difference between the 0.1 g/L chitosan group and the vitamin C group(P > 0.05),but the T-AOC activity,GSH activity,SOD activity and CAT activity were high in the 0.1 g/L chitosan group in the vitamin C group,the MDA content and ROS level were lower than those of the vitamin C group.The preservation effect of adding 0.1 g/L chitosan to the diluent was significantly better than that of the control group and the gentamicin group(P < 0.05).Therefore,among the four test groups,the preservation effect of adding 0.1 g/L chitosan to the diluent is the best.3.This study analyzes the types and distribution of microorganisms in semen from the changes in microbial composition at the three levels of phylum,order,and genus,and found that the bacteria that dominate at the phylum level in semen mainly include Proteobacteria(Proteobacteria),Firmicutes(Firmicutes)and Bacteroidetes(Bacteroidetes);The dominant bacteria at the class level mainly include ?-proteobacteria(Gammaproteobacteria),Clostridia(Clostridia)and ?-Proteobacteria(Gammaproteobacteria);The dominant strains at the mesh level are Enterobacteriales(Enterobacteriales),Pseudomonadales(Pseudomonadales)and Clostridiales(Clostridiales);Among them,the most dominant is Enterobacteriales,which account for 60%?80% of the total Proteobacteria.The research results show that the Chitosan group and the gentamicin group are added to the Proteobacteria(Proteobacteria),Enterobacteriales(Enterobacteriales),The abundances of Pseudomonadales(Pseudomonadales)and Serratia(Serratia)were significantly lower than other groups(P < 0.05).After the semen was stored for 5 days,the 16 S r DNA sequencing results showed that the addition of 0.25 g/L gentamicin and 0.1 g/L chitosan was significantly lower than the control group(P < 0.05).The content of Pseudomonas and Pseudomonas also decreased accordingly.However,the content of some bacteria has also increased.This indicates that chitosan has an antibacterial effect similar to gentamicin,and only has an inhibitory effect on some bacteria.Therefore,this study proved that adding chitosan to the diluent of boar semen preservation at room temperature can effectively improve the quality of semen preservation,and the optimal concentration is 0.1 g/L.The addition of 0.1 g/L chitosan can significantly improve sperm motility,plasma membrane intact rate,acrosome intact rate,T-AOC,SOD,GSH and CAT activities after sperm preservation at room temperature,and significantly reduce MDA content and ROS level,and The antibacterial effect reaches the effect of traditional antibiotics such as gentamicin,indicating that it can replace the use of antibiotics to a certain extent,which is of great significance for the study of boar semen preservation at room temperature.