Lipopolysaccharide Stimulates the Growth of Bacteria That Contribute to Ruminal Acidosis

Gram-negative bacteria contain lipopolysaccharide (LPS) coating their thin peptidoglycan cell wall. The presence of LPS has been suggested to be associated with a metabolic disorder of cattle-ruminal acidosis-through affecting ruminal bacteria. Ruminal acidosis could reduce feed intake and milk production and increase the incidence of diarrhea, milk fat depression, liver abscesses, and laminitis. However, how LPS affects bacteria associated with ruminal acidosis has not been studied. In this study, we investigated how LPS affects the growth of ruminal bacteria by pure cultures, including those that contribute to acidosis, and the functional genes of ruminal bacteria. Thus, this work serves to further our understanding of the roles of LPS in the pathogenesis of ruminal acidosis, as well as providing information that may be useful for the prevention of ruminal acidosis and reducetion of economic losses for farmers.