The Effect And Mechanisma Of Oregano Essential Oil On Semen Quality Of Boar Semen

The problems like poor sperm motility, abnormal sperm morphology, decreased sexual behavior, etc in boars have become limiting factors in production efficiency and economic effectiveness in boar stations.Our privous study found that diet with n6/n3 Oregano Essential Oils(PUFAs) ratio 6.6 combined with 400mg/kg VE could improve boar sperm motility in 8-14 weeks after diet treatment. Diet enriched PUFA elevated the level of sperm MAD and susceptibility of sperm to reactive oxygen species. The main constituents of the Oregano Essential Oils(OEO) are thymol and carvacrol which show powerful antioxidant activity and can inhibit lipid peroxidation.We exepect that apply oregano essential oil in boar diet to inhibit lipid peroxidation.In this study,we inverstigated the effects of different levels of oregano essential oil on boar reproductive performance, semen antioxidant capacity and sperm membrane structure and function.Thirty-five Duroc boar with indentical age, weight and semen quality para meters were divided into four groups ad libitum, each group has eight to nine repetition, each boar has one repeat. Control group was fed with basal diet which supplemented with 100 mg/kg VE, while experimental group was fed with diet supplemented with 250, 500 and 750 mg/kg OEO respectively.The trail lasted for sixteen weeks. Then samples were immediately collected. The results showed as follows:1. Boar reproductive performance: compared with control group, sperm motility in treatments supplemented with 250 and 500 mg/kg OEO have a trend of increase(P=0.10) in week sixteen; in the treatment supplemented with 500 mg/kg OEO, the beheaded sperm rate was significantly decreased in week eight(P<0.01), and normal sperm morphology rate was significantly elevated in week sixteen(P<0.01); in the treatment supplemented with 500 mg/kg OEO, both sperm neck deformity rate and bobtailed rate was significantly decreased in week eight(P<0.05).2. Antioxidant capacity: compared with control group, in the treatment supplemented with 250 mg/kg OEO, the level of sperm MDA content was decreased in week twelve and sixteen(P<0.05), serum GSH-PX activity in week twelve and seminal plasma SOD and GSH-PX activity in week sixteen was elevated(P<0.05). In the treatment supplemented with 500 mg/kg OEO, serum MDA content in week twelve, sperm MDA content in week twelve and sixteen was significantly decreased; serum SOD activity in week twelve and sixteen, sperm SOD activity in week eight and twelve, seminal plasm SOD activity in week sixteen was significantly elevated(P<0.05); serum GSH-PX activity in week twelve, sperm and seminal plasm GSH-PX activity in week sixteen was also significantly elevated(P<0.05). In the treatment supplemented with 750 mg/kg OEO, serum MDA content twelve was significantly decreased in week twelve(P<0.05)and seminal plasm SOD activity was significantly elevated in week sixteen(P<0.01).3. Sperm membrane structure and function: sperm viability in the treatment supplemented with 250 and 750 mg/kg OEO was elevated over time, the highest increase rate of viability is in the treatment supplemented 500 mg/kg OEO,and the sperm viability in the treatment supplemented 750 mg/kg OEO was lower than the 500 mg/kg OEO in week sixteen(P<0.01). However, sperm membrane fluidity, mitochondrial membrane potential and sperm membrane integrity(Host) has no significant difference when compared with control group(P>0.05).In summary, diet supplemented with 500 mg/kg OEO can improving boar semen antioxidant capacity, inhibit sperm lipid peroxidation to promote sperm motility. Diet supplemented with OEO could achieve better effect of boar semen quality than diet supplemented with 100 mg/kg VE.