Effect Of Weaning Age On Growth Performance,Digestion And Metabolism And Reproductive Hormone Level Of Hu Sheep Lamb

The experiment was conducted to study the effects of weaning age on growth performance,digestion and metabolism,and reproductive hormone content of ewes in order to provide evidence for the feasibility of early weaning of Hu lambs under the condition of supplementing pellet feed,the best weaning time was determined,and the reference was provided for shortening the lambing interval of ewes.A total of 90 hu lambs with birth date less than 3 days,good health,similar parity and no disease were selected and randomly divided into 3 groups with 30 lambs in each group and 3 replicates in each group,repeat 10 each.The rats were weaned at the age of 25 Days(Group Ⅰ),35 days(Group Ⅱ)and 45 days(control group),respectively,after 7 days of pellet feeding.At the same time,the changes of reproductive hormone levels in three groups of ewes were followed up.The main findings are as follows:1.The apparent digestibility of crude protein(CP)of lambs in Group Ⅰ was significantly lower than that in Group Ⅱ and control(P<0.05),there were significant differences in nitrogen intake,net protein utilization and biological value of protein between the experimental group and the control group(P<0.05).On the day of weaning,the level of serum high-density lipoprotein(HDL-C)in the experimental group Ⅰ was significantly higher than that in the Experimental Group Ⅱ and the control group(P<0.01),and the level of HDL-C in the Experimental Group Ⅱ was significantly higher than that in the control group(P<0.05),the levels of serum Low-density lipoprotein(LDL-C)in the trial group Ⅰwere significantly higher than those in the control group(P<0.01),and significantly higher than those in the Trial Group Ⅱ(P<0.05),serum total cholesterol(TC)was significantly higher in group I than in Group Ⅱ and control(P<0.05).Serum triglyceride(TG)was significantly higher in Group Ⅱ than in Group Ⅰ and control(P<0.01)At the age of 90 days,the level of serum glucose(Glu)in Group Ⅱ was significantly higher than that in the control group(P<0.05),and the activity of serum Alkaline phosphatase(ALP)in Group Ⅱ was significantly higher than that in the control group on the day of weaning(P<0.05).2.At the age of 30 days,the body length index and Fattening Index of Group Ⅰ were significantly higher than those of Group Ⅱ and control group(P<0.05).At the age of 60 days,the body length index of Experimental Group Ⅰ was significantly lower than that of control group(P<0.05),and the body length index of Experimental Group Ⅱ was significantly higher than that of Experimental Group Ⅰ and Control Group(P<0.05),chest circumference index in Group Ⅱ was significantly higher than that in Group Ⅰ(P<0.05).Economic Benefit Test Group Ⅱ>control group>Test Group Ⅰ.3.At the age of 60 days,the E2 content of ewes in test group Ⅱ was significantly higher than that in control group(P<0.05),the serum prolactin(PRL)level in Group Ⅰ was significantly higher than that in Group Ⅱ and control group(P<0.01).The results showed that weaning at 35 days of age was feasible,and early weaning could effectively increase E2 content in serum of Hu sheep ewes,promote the recovery of ewes’ reproductive function and facilitate ewes to enter the next estrus.