Effects Of Light On Melatonin?Testosterone And Semen Quality Of Inner Mongolia Cashmere Male Goats

Changing the light cycle can improve reproductive performance and utilization efficiency of male goats in the practice,by artificially control the light,this experiment were to study the effect of different light time on melatonin and testosterone and semen quality of Inner Mongolia cashmere male goats.The experimental results are as follows:1?Blood samples were collected from May 2018 to April 2019,and the changes of serum melatonin and testosterone in Inner Mongolia cashmere male goats were analyzed.The results showed that the serum melatonin concentration increased rapidly from May to September 2018,peaked in September,then decreased from September 2018 to January 2019,and increased slowly from January to April 2019;The Serum testosterone concentration increased from May to October 2018,peaked in October,decreased from October 2018 to February 2019,increased from February to March and decreased from March to April.In the natural condition,the serum melatonin and testosterone were significantly correlated(r=0.51463).2?The light control experiment started in late June 2019,and according to the season and light conditions,6 treatments were designed which including the non-breeding season control group(SN),the non-breeding season short daylight group(SS),the non-breeding season long daylight group(SL);the breeding season control group(WN),the breeding season short daylight Group(WS),the breeding season long daylight Group(WL).Blood and semen were collected 10 times per week in non-breeding season(June-August),blood 11 times and semen 8 times per week in breeding season(September-November).The supernatant was collected by centrifugation for the determination of MT and T hormone levels,and semen quality was determined.During the non-breeding season,the serum and seminal plasma melatonin concentration in the SS group was significantly higher compared to the SN group(P<0.05),and the serum and seminal plasma melatonin concentration in the SL group was significantly lower compared to the SN group(P<0.05);during the breeding season,the serum and seminal plasma melatonin concentration in the WS group was significantly higher compared to the WN group(P<0.05),and the serum and seminal plasma melatonin concentration in the WL group was significantly lower compared to the WN group(P<0.05);during the non-breeding season,the serum and seminal plasma testosterone concentration of the SS group was significantly higher compared to the SN group(P<0.05),and the serum and seminal plasma testosterone concentration of the SL group was significantly lower compared to the SN group(P<0.05);during the breeding season,the serum and seminal plasma testosterone concentration of the WS group was significantly higher compared to the WN group(P<0.05),the serum and seminal plasma testosterone concentration of the WL group was significantly lower compared to the WN group(P<0.05),the results showed that the difference of light time had a significant effect on melatonin and testosterone in male goat serum and seminal plasma.During the breeding season,the seminal viability?volume and motility parameters in the WS group was significantly higher than the WN group(P<0.05),and in the WL group was significantly lower than the WN group(P<0.05).On the whole,the levels of melatonin and testosterone in the serum of Inner Mongolian cashmere goats showed periodic changes within the whole year,and their periodic changes were significantly correlated.The artificial adjustment of the light time has a significant effect on melatonin and testosterone content in the serum and semen of Inner Mongolia cashmere male goat,reducing the light time can significantly improve the semen quality of rams during the breeding season.