Effects Of Procyanidins And Bamboo Leaf Flavonoids On The Cryopreservation Of Beef Bull Semen

Semen cryopreservation is a crucial technical aspect of artificial insemination,and it has a significant effect on improving the utilization rate of breeding males with good physique and strong reproductive performance.At present,the technology of cryopreservation of bovine semen is not yet fully mature.Due to the composition of the diluent,the balance time,the freezing method and other reasons,the sperm will be affected by oxidative stress and freezing shock,resulting in decreased vitality and reduced fertilization rate.Proantho cyanidins have superior functions such as antioxidation and anti-cancer,and belong to a class of natural polyphenol compounds.Bamboo leaf flavonoids have similar effects to proantho cyanidins.It is derived from natural bamboo leaves.It is the most important active substance among them and can also improve the body’s immunity.In this study,to explore the effect of adding oligomeric proantho cyanidins(OPC)and bamboo leaf flavonoids(BLF)to the frozen diluent of bovine semen on the preservation of bovine semen.Sperm analyzer detection method,hypotonic swelling method,CFDA/PI double staining technique were used to detect sperm motility,kinematic parameters,plasma membrane intact rate and acrosome intact rate after freezing and thawing;ELISA technique was used to detect superoxide dismutation in frozen-thawed semen Enzyme(SOD),catalase(CAT)and glutathione peroxidase(GPx)activities,malondialdehyde(MDA)and reactive oxygen species(ROS)levels.The results are as follows:1.Adding 0,10,30,50,70 mg/L of OPC to the bovine frozen diluent,after freezing and thawing,50 mg/L of oligomeric proantho cyanidins significantly improved the vitality,kinematic parameters of sperm(VCL,VAP,VSL),plasma membrane intact rate,acrosome intact rate and antioxidant enzyme activity(P<0.05),reduced the level of MDA and ROS in semen significantly(P<0.05).2.Adding 0,2,4,6,8 mg/L of BLF to the frozen diluent of cattle,after freezing and thawing,4 mg/L of bamboo leaf flavonoids can significantly improve the vitality,kinematic parameters of sperm(VCL,VAP,VSL),plasma membrane intact rate,acrosome intact rate and antioxidant enzyme activity(P<0.05),reduced the level of MDA and ROS in semen significantly(P<0.05).3.Combination of different concentrations of OPC and 4mg/L BLF is added to the frozen diluent of cattle.Compared with adding BLF alone,adding 30mg/L OPC+4mg/L BLF significantly improved sperm motility and kinematic parameters after freezing and thawing VCL,VAP,ALH),plasma membrane intact rate,acrosome intact rate and antioxidant enzyme activity(P<0.05),reduced the level of MDA and ROS in semen significantly(P<0.05).In this study,the results showed that adding 50mg/L OPC and 4mg/L BLF to the frozen diluent of bovine semen significantly improved the quality of semen after freezing and thawing.Compared with single addition,this combined addition method(30mg/L OPC+4mg/L BLF)further improved sperm motility,kinematic parameters,plasma membrane intact rate and acrosome intact rate after freezing and thawing,and antioxidant enzymes activity in semen,reduced the levels of MDA and ROS.