Effects Of Total Mixed Diet Added With Yeast And Glucose On Growth Performance,Serum Index And Rumen Fermentation In Ewes

The objectives of this study were to investigate the effects of total mixed diets added with active saccharomyces cerevisiae and glucose on growth performance,serum biochemical indexes,rumen fermentation and rumen microflora in ewes,and to provide theoretical basis for their application in production practice.Thirty healthy ewes with similar age and body weight were randomly divided into three groups: the control group,yeast group and glucose group,with 10 animals each.The control group was fed a total mixed diet,the yeast and glucose groups were fed TMRs added with 0.5% active saccharomyces cerevisiae and 1.0% glucose,respectively.The study lasted for 64 days with 14 days for adaptation followed by 50 days of sampling.During the experimental period,the weight measurement and sample collection were carried out according to the experimental design.This study is divided into four experiments:Experiment 1: Effects of total mixed diets added with active saccharomyces cerevisiae and glucose on growth performance in ewes.No significant differences were observed in the initial weight,final weight,average daily feed intake,average daily gain,net gain weight and feed efficiency among treatments(P>0.05).Experiment 2: Effects of total mixed diets added with active saccharomyces cerevisiae and glucose on serum biochemical indexes in ewes.The results showed no significant differences in the serum concentrations of glucose(GLU),triglyceride(TG),total cholesterol(TC),alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),total protein(TP),albumin(ALB)and UREA(UREA)among treatments.Experiment 3: Effects of total mixed diets added with active saccharomyces cerevisiae and glucose on rumen fermentation in ewes.No significant differences in rumen p H and rumen concentrations of ammonia nitrogen(NH3-N)were observed among treatments(P > 0.05).Rumen concentration of propionic acid(PA)and total volatile fatty acid(TVFA)in the animals of glucose group were significantly higher than in those of control group(P<0.05),while rumen concentration of acetic acid(AA)in animals of glucose group was significantly higher than in those of yeast group(P < 0.05).Compare to the control group,the ratio of B to C in the glucose group was decreased significantly(P < 0.05).There were no significant differences observed in the concentrations of butyric acid(BA),isobutyric acid(IBA),valeric acid(VA)and isovaleric acid(IVA)among treatments(P>0.05).Experiment 4: Effects of total mixed diets added with active saccharomyces cerevisiae and glucose on rumen microflora.The 16 S r RNA gene high-throughput sequencing technology was used,and the results showed that: 1)at the phylum level,Bacteroidetes,Firmicutes,Proteobacteria and Actinobacteria were the dominant phylum,no significant differences was observed in the relative abundance of flora among treatments;2)at the genus level,prevotella＿7,prevotella＿1 and Prevost＿ucg-001 were the dominant genera.No significant differences were observed in the relative abundance of flora among treatments also.The results of this study showed that adding 0.5% active saccharomyces cerevisiae to the total mixed granular diet had no significant effect on the growth performance,serum index and other rumen fermentation traits of the ewes.However,adding 1.0% glucose to the total mixed granular diet could significantly increase the concentration of propionic acid and volatile fatty acids in rumen and reduce the ratio of ethylene to propylene,there were no significant differences observed for growth performance,serum index and other rumen fermentation parameters in the current study conditions.Yeast and glucose have no significant differences on the composition of rumen microflora,but they have certain influence.