Effects Of Melatonin On Growth Performance,Pregnancy Rate And Semen Quality Of Sheep

In this study,weaning lambs,adult ewes and breeding RAMS were treated with melatonin.To explore the effects of embedding and feeding melatonin on growth performance,oxidative stress and immune capacity of lambs after weaning.The effect of melatonin-implantation and injection on the Pregnancy rate of ewe during estrus;Effects of feeding and embedding melatonin on semen quality of RAMS.Thirty healthy 65-75 day-old lambs with similar body weight were randomly divided into five groups.The experimental group was implanted with 60 mg and 90 mg melatonin,respectively.The piglets were fed1 mg/kg and 3 mg/kg melatonin.To study the effects of implanting and feeding melatonin on weight gain,growth rate,oxidative stress and immune indices of lambs after weaning.The results showed as follows :(1)compared with the control group,the average daily gain in 90 mg group was significantly increased(P<0.05),and the average daily gain in 1 mg/kg group was extremely significantly increased(P<0.01);The growth rate of 90 mg group and 1 mg/kg group was significantly increased(P<0.01);The average daily increase of body height and chest depth in 90 mg group were significantly increased(P<0.01),and the average daily increase of chest depth was significantly increased(P<0.05).And the average daily increase of body height and chest circumference in 3 mg/kg group was significantly increased(P<0.05).(2)Cortisol concentration in 90 mg group and 1 mg/kg group was significantly decreased(P<0.01),SOD content in 1mg/kg group was significantly increased(P<0.05),malondialdehyde(MDA)was significantly decreased(P<0.01);(3)The contents of immunoglobulin A(Ig A)and immunoglobulin M(Ig M)in 1 mg/kg group were significantly increased(P<0.05).Newborn ewes were selected to be in estrus at the same time.In the study,40 ewes were implanted with 60 mg melatonin,24 ewes were treated with 90 mg melatonin,and 62 ewes were injected with 2 m L melatonin during semen infusion.To study the effect of melatonin on estrus and conception rate of ewe during estrus.The results showed that the conception rate of 60 mg group(65%),90 mg group(70.8%),2m L group(71.4%)and control group(55%)was significantly higher than that of control group(P<0.01).Sixteen healthy RAMS were randomly divided into four groups.the experimental groups were fed 10mg/d,20 mg/d and 40 mg/d melatonin,respectively.12 healthy RAMS were randomly divided into three groups,and the experimental group was implanted with 60 mg melatonin and 180 mg melatonin,respectively,In order to study the effect of melatonin on semen quality of RAMS in a short period of non-breeding season.The results showed that feeding and embedding melatonin had no significant effect on semen quality of RAMS in a short period of time(P>0.05).According to the results,it concluded that implanting and feeding melatonin can alleviate oxidative stress,enhance immune capacity and improve growth performance of sheep after weaning.The best effect is implanting 90 mg and feeding 1 mg/kg melatonin.At the same time,the implantation of 60 mg and 90 mg MT and the injection of 2 m LMT at the same time could improve the conception rate,reproductive system and reproductive performance.Our study provides technical support for animal husbandry in reproductive development,and theoretical reference for the use and promotion of melatonin.