The Effects Of Folic Acid On Semen Quality,Serum Antioxidant Capacity And Endocrine Hormones Of Ram Under Moderate Heat Stress

The objective of this experiment was to investigate the effects of folic acid on semen quality,serum and seminal plasma antioxidant capacity and endocrine hormones in rams suffering moderate heat stress.Ten healthy 3-year-old Dorper rams of similar body weight,in good body condition,and with records of good semen quality in the consecutive two years were used randomized trial design.The test factor was coated folic acid,0 mg and 4 mg/kg BW/d CFA added according to animal body weight.The feeding experiment included 10 days of adaptation and was followed by 90 days of the trial period.The results showed that:1.As for semen quality: under moderate heat stress,the addition of CFA to the diet significantly increased sperm motility,sperm plasma membrane integrity,and sperm DNA integrity(P < 0.05),and markedly decreased the percentage of abnormal sperm(P < 0.05)in rams;The time treatment had a highly significant effect on sperm motility,sperm density,plasma membrane integrity,percentage of abnormal sperm,DNA integrity,VAP,and STR(P < 0.01);CFA by time interaction significantly increased sperm DNA integrity in rams under moderate heat stress(P < 0.01).2.Serum and seminal plasma FA levels: under moderate heat stress,the addition of CFA to the diet had no significant effect on FA levels in the serum of rams(P > 0.05),but significantly increased FA levels in the seminal plasma(P < 0.05).3.Serum antioxidant indexes: under moderate heat stress,the addition of CFA to the diet significantly increased serum GSH-Px and T-AOC activities(P < 0.05),significantly increased serum CAT activity(P <0.01),and significantly reduced serum MDA content(P < 0.05);The time treatment had a highly significant effect on serum SOD,CAT and MDA(P < 0.01);CFA by time interaction significantly increased serum CAT activity in rams under moderate heat stress(P < 0.01).4.Seminal plasma antioxidant indexes: under moderate heat stress,the addition of CFA to the diet highly significantly increased the seminal plasma SOD activity(P < 0.01),significantly increased the seminal plasma T-AOC activity(P < 0.05),and significantly decreased the seminal plasma MDA(P < 0.05)in rams.The time treatment had a highly significant effect on seminal plasma SOD,CAT,T-AOC and MDA(P < 0.01);CFA by time interaction significantly reduced the seminal plasma MDA content of rams(P <0.01),significantly increased the seminal plasma T-AOC activity of rams(P < 0.01)and significantly increased the seminal plasma SOD activity of rams(P < 0.01).5.Serum endocrine hormones: under moderate heat stress,the addition of CFA to the diet significantly increased serum LH and T levels in rams(P < 0.05);The time treatment had a highly significant effect on serum levels of FSH,LH,T,T3,T4 and COR(P < 0.01).6.Seminal plasma endocrine hormones: under moderate heat stress,the addition of CFA to the diet considerably increased seminal plasma FSH,LH,and T levels in rams(P < 0.05);The time of treatment had a highly significant effect on seminal plasma FSH,LH,T,T3,T4 and COR levels(P < 0.01);CFA by time interaction significantly increased seminal plasma T and T4 levels in rams(P < 0.01)and significantly increased T3 levels(P < 0.05).In conclusion,the addition of 4 mg/kg BW/d of CFA to the diet of rams suffering moderate heat stress can improve the antioxidant function of the body,maintain the balance of the endocrine system of the body,improve the stress resistance of the ram,effectively alleviate the damage of heat stress on the reproductive performance,and improve the semen quality.