Abstract: In recent years,with the attention paid to the function of microorganisms,people’s research on intestinal microbes is also increasing.In the gut of ruminants,there are a large number of microorganisms,which play a very important role in the host’s nutritional metabolism,immune function,etc.,and are one of the key factors affecting body health.Intestinal microbes is affected by diet composition,age,genotype and other factors of ruminants,and dietary composition is the most important factor affecting intestinal microbes.If the diet changes,the crude fiber,protein,carbohydrate and other nutrients will change,and the intestinal microbes will also change.There are beneficial microorganisms in the body of ruminants,which have a positive effect on the animal body,such as Ruminococcus,Micrococcus luteus,Enterococcus bovis,etc.,while some harmful bacteria (such as Clostridium,Zurichbacterium,etc.) destroy the homeostasis of the internal environment of ruminants,reduce the immunity and disease resistance of the body,and are prone to diseases,which seriously affect the health of ruminants.In addition to intestinal microbes affecting the body health of ruminants,probiotics and nutrients also play a regulatory role in the body health of ruminants,and the general measures are to add beneficial probiotics or nutrient diets to the diets of ruminants,which can not only supplement the daily nutrition level,but also prevent the proliferation of harmful microorganisms,so as to ensure the health of ruminants.The authors review the factors affecting the intestinal microbes of ruminants and the effects of probiotics and nutrients on the healthy production of ruminants,aiming to provide a theoretical reference for the reasonable regulation of the intestinal microbes of ruminants and its healthy development,so as to promote the development of animal husbandry.

Key words: intestinal microbes; ruminants; probiotics; nutrient