Effects Of Yeast Culture On Production Performance,Apparent Digestibility,Antioxidant Function And Immunity Ability In Dairy Cow

Yeast culture is the product of fully anaerobic fermentation of yeast,which consists of degeneration of the culture medium yeast cell and yeast metabolites.The yeast culture contains a lot of amino acids,organic acids,vitamins,enzymes,polypeptide,mannan oligosaccharide,β-glucan,unknown growth factor,etc.A large number of studies have shown that yeast culture can improve rumen enviroment,and increased diet palatability,the dry matter intake,organic matter digestibility and utilization,milk production,and milk quality.But at the present,the product of yeast culture on the market is high price and add less,and don’t fit the development of farm.The feeding trial was conducted to investigate domestic yeast culture as feed raw materials supplementation on production performance,apparent digestibility,antioxidant and immune capacity in cow.This thesis was conducted in the following two sections.In the first section,This experiment was conducted to study the effects of yeast culture on production performance and nutrient apparent digestibility of the period of lactation of Holstein dairy cow.Two hundred and eight lactating dairy cows with similar lactations,lactation days and milk yield were randomly divided into two groups in pair.The control group was fed with total mixed ration of the farm(basal diets),and the trail group was fed with basal diets and 400g/(head·d)yeast culture.The feeding trial lasted for 60 days with 10 pre-feeding days and 50 trial days.Feed intake,milk yield,milk quality and nutrient apparent digestibility of the control and trail group were determined.The results showed as follow s:1)Cows were fed 400g yeast cultures every day can increased the dry matter intake(P<0.01)and improved the milk yield(P<0.05).2)Cows were fed 400g yeast cultures every day can improve the fat rate and protein content in milk(P<0.05)and reduce the somatic cell count(P<0.05).3)The aPparent digestibility of neutral detergent fiber and acid detergent fiber of trial group was higher than that of control group(P<0.05);The nutrient apparent digestibility of Ca of trial group was significantly higher than that of control group(P<0.01).In conclusion,the yeast culture can improve the production performance of dairy cows and the nutrient apparent digestibility.In the second section,to investigate the effects of yeast culture replacing deputy feed on production performance,antioxidant function and immune capacity in dairy cow.A total of 56 Holstein dairy cows with the similar lactation,DIM,milk yield were chosed,and then randomly divided into two groups.The control group was fed with basal diet and yeast culture group was fed with basal diet supplemented with 3%yeast culture as well as reduced 3%deputy feed,and there is no difference between two groups of nutrition level.The feeding trial lasted for 80 days with 20 pre-feeding days and 60 trial days.The results showed as follows:1)Adding 3%yeast culture increased the dry matter intake(P<0.01)and improved the milk yield(P<0.05).2)Adding 3%yeast culture can improve the fat rate and protein content in milk(P<0.05)and reduce the somatic cell count(P<0.05).3)Adding yeast culrure can increase the superoxide dismutase activity(P<0.01),and significantly improve the total antioxidant capacity(P<0.05).4)Adding yeast culture can increase the serum Immunoglobulin A and Immunoglobulin M contents(P<0.05).In conclusion,the yeast culture can improve the production performance of dairy cows,effectively enhance the antioxidant and immune capacity.