Abstract: At present, cattle reproduction barrier is one of the important factors affecting the development of cattle industry.The uterus is the heart of new life.Uterine microecological imbalance can not only damage endometrial function, but also affect ovarian function, leading to infertility and causing huge losses to animal husbandry economy.Recent studies have found that there is a microbial community in bovine uterus, which contains pathogenic bacteria and opportunistic bacteria in addition to the normal flora, and these microorganisms will dynamically change with different growth cycles and different clinical conditions of cattle.The pathogenic microorganisms inducing bovine reproductive diseases mainly include bacteria, fungi and viruses, which destroy the homeostasis of the reproductive tract by infecting epithelial cells or secreting toxic metabolites.The normal microbiota can maintain the microecological balance of the reproductive tract by interacting with the immune system to prevent the colonization of pathogenic microorganisms.Therefore, microbiota plays an important role in cattle production and reproduction.Although the research on the factors affecting the changes of microbiota is not deep enough, it has been confirmed that hormones, health status, and environmental factors have different effects on the abundance and diversity of microorganisms in bovine uterus.The author compared the microbial composition of healthy and diseased bovine uterus, and further analyzed the factors of uterine microbial imbalance, so as to provide reference basis for the prevention and treatment of bovine uterine related diseases.

Key words: cattle; uterus; microbe; pathogenic bacteria; reproductive tract