Effects Of Different Fiber Sources On Microbial Flora And Nutrition Utilization For Sika Deer

Sika deer is a kind of ruminants with the high economic and medicinal value in china.In the wild,sika deer likes to eat plants and grass,whereas under the artificial rearing,they prefer plant-based feedstuffs with little concentrated feeds.Different feed source and nutrient levels will have effects on the sika deer rumen environment.Therefore,we study the effects of different crude fiber sources on microbial flora,rumen environment,serum biochemical indicators and nutrient digestibility in the experiment.One group had free access to concentrate and corn stalk(A group),and the other group to concentrate and oak leaves(B group).The microbial diversity in rumen fluid was analyzed by high-throughput pyrosequencing technology.We studied the changes of different feed source and nutrient levels on microbial flora and rumen environment and nutrient utilization,and to provide theoretical basis for optimizing the diet structure and feeding standard of sika deer under artificial feeding condition.The results showed that: at the phylum level,Bacteroidetes and Firmicutes were predominant in A and B group,respectively represented by 41.66% and 38.97%(A group),67.23% and 11.37%(B group)of 16 S rRNA gene sequences;at the genus level,the genus Prevotella,Butyrivibrio and Ruminococcus had a high abundance with an average 18.07%,2.81% and 1.51% in A group,while Prevotella,Succinivibrio,Succiniclasticum and Ruminobacter were predominant with an average 41.4%,13.12%,2.56% and 1.56% in B group.The internal environment parameters and serum biochemical indexes of A and B group were detected.The results showed that,compared to B group,the concentration of VFAs,acetic acid,propionic acid,butyric acid,NH3-N,and BCP in ruminal content of sika deer was significantly lower in A group(P<0.05),the results of serum biochemical indicators also proved this conclusion.In addition,PH and the concentration of endotoxin and histamine in ruminal content and serum was not significant(P>0.05).We also surveyed the effects of the different crude fiber source diets on nutrient digestibility.The results showed that dry matter,organic matter and crude fiber digestibility were significantly affected by different concentrate supplements(P<0.05).Although the NDF intake of B group was significantly lower than that of A group(P<0.05),the digestibility was significantly higher than that of A group(P<0.05).To conclude,the results showed that the diets with corn stalks and oak leaves were not only able to satisfy the sika deer nutrient needs,but also stabilize the rumen environment of sika deer.Compared to A group,rumen microbial flora of B group can effectively degrade cellulose and other nutrients,and the concentrations of VFAs,acetic acid,propionic acid,butyric acid,NH3-N and BCP are relatively higher,improving its dry matter,organic and neutral detergent fiber digestibility.