纤维素酶对羔羊瘤胃发酵特性、纤维素分解菌及挥发性脂肪酸吸收代谢相关基因表达的影响OA

The aim of this study was to study the effects of cellulase on rumen fermentation characteristics,cellulolytic bacteria and the expression of genes related to volatile fatty acid(VFA)absorption and metabo-lism in lambs.Thirty-six 10 day old male Hu sheep lambs with normal development and similar body weight[(3.0±0.5)kg]were randomly divided into two groups,with 18 lambs in each group.The control group was fed with the starter without cellulase,and the cellulase group was fed with the starter with 0.1％cellulase,the experimental period was 110 d.The lambs were fed with the ewes from 1 to 9 days of age.The lambs were separated from the ewes at 10 days of age,fed in a single barn,and fed with milk replacer and starter,the lambs were weaned at 61 days of age.The results showed that:①compared with the control group,before and after weaning,adding cellulase could significantly reduce the content of ammonia nitrogen(NH3-N)in the rumen of lambs(P<0.05);before weaning,the contents of acetic acid,propionic acid,butyric acid,isobutyric acid and isovaleric acid in the cellulase group increased signifi-cantly(P<0.05),while rumen pH and valeric acid content decreased significantly(P<0.05);after weaning,the contents of acetic acid,propionic acid and VFA in rumen of cellulase group decreased significantly(P<0.05).② Compared with the control group,before and after weaning,the addition of cellulase in the starter significantly increased the number of filobacterium succiniclate in the rumen of lambs(P<0.05),and before weaning,significantly increased the number of butyrivibrio fibrisolvens and Ruminococcus flave faces(P<0.05).③ Compared with the control group,before weaning,the relative expression of 3-hydroxy-3-methyl-glutaryl CoA lyase(HMGCL)in rumen epithelial cells added with cellulase in the starter was extremely sig-nificantly increased(P<0.01),and the relative expression of monocarboxylate transporter 1(MCT1),Na+/H+exchanger 4(NHE4)and acyl CoA short chain synthase 1(ACSS1)mRNA was significantly increased(P<0.05);after weaning,the relative mRNA expressions of monocarboxylate transporter 4(MCT4)and HMGCL in rumen epithelial cells were significantly increased(P<0.05),while the relative mRNA expressions of 3-hydroxy-3-methylglutaryl CoA synthase 2(HMGCS2)were significantly decreased(P<0.05).In conclusion,adding cellulase to the starter can improve rumen fermentation,promote the growth of cellulolytic bacteria,and significantly regulate the expression of genes related to absorption and metabolism in rumen epithelial cells,so as to maintain the stability of the rumen internal environment by regulating the body's metabolic pathway.