Effects Of Fat Supplementation On Milk Yield,Milk Composition And Blood Indexes Of Grazing Yili Horses

In this study,the effects of supplemental fat feeding on milk yield,milk composition and blood indexes of grazing Yili horses were investigated.Fourteen Yili horses with similar foal date,lactation period and milk yield were randomly divided into two groups: concentrate group(n = 7)and fat group(n= 7).All the experimental horses were fed with grazing and supplementary feeding.Among them,the concentrate group was fed with 1 kg concentrate supplement every day,and the fat group was fed with 1kg concentrate supplement and 400 g fat(balanced emulsified oil powder)every day.One month later,the fat was increased to 600 g and drank freely.After 7 days of prefeeding,the normal feeding experiment lasted for 2 months.The results showed that: 1)Compared with the concentrate group,the milk yield of the fat group was significantly higher than that of the concentrate group(P < 0.05).2)There was no significant difference in milk fat rate,milk protein rate,lactose rate,total solids,somatic cell count,non-fat solids and urea nitrogen between concentrate group and fat group(P > 0.05).3)Horse milk lauric acid and linoleic acid in fat group were significantly higher than those in concentrate group(P < 0.05),but pentadecanoic acid,palmitoenoic acid,heptadecanoic acid and γ-linolenic acid in concentrate group were significantly higher than those in fat group(P < 0.05).4)There was no significant difference in the concentrations of glucose,triglyceride and insulin between the concentrate group and the fat group at 0 h before and 2 h after feeding on the 20 th day,40 d and 60 d(P > 0.05).The plasma high density lipoprotein in the fat group was significantly higher than that in the concentrate group at 2 hours after feeding on the 20 th day and 60 days(P < 0.05).On the 40 th day of the experiment,the plasma free fatty acid concentration of Yili horse in the fat group was significantly higher than that in the concentrate group at 0 hours before feeding and 2 hours after feeding(P < 0.05).5)There was no significant difference in catalase,glutathione peroxidase,superoxide dismutase activity and malondialdehyde concentration between concentrate group and fat group at 20,40 and 60 days before feeding and 2 hours after feeding(P > 0.05).To sum up,the supplementation of fat can increase the milk yield,milk fat yield,the content of lauric acid and linoleic acid in milk and the absorption and utilization of fatty acids,but has no effect on the composition of horse milk and the ability of antioxidation.