Inflammation is an important response of the innate immune system, but feed intake is reduced in cattle experiencing inflammatory reactions. Acute and chronic inflammation leads to appetite depression via neural and hormonal mechanisms, and may impair the ability of the rumen in digesting feed via interactions between animal hormones and ruminal microbes. Lipopolysaccharide is a molecule that elicits a temporary inflammatory response, and is used in research studies aimed to evaluate the consequences of inflammation on cattle health and performance. In this experiment, beef steers received a lipopolysaccharide injection that decreased their feed intake for 48 h compared with non-injected cattle. As expected, this response was associated with physiological reactions known to modulate gastrointestinal motility and satiety centers in the brain. Lipopolysaccharide administration also reduced the total number of bacteria in the rumen, which appears to have caused a decrease in ruminal feed degradability by the microbes. The rumen and its microbial population have receptors that interact with mammalian hormones, including those elicited during inflammation. Therefore, this experiment provides novel insights into potential host-microbiome interactions during inflammatory reactions and highlights the importance of acknowledging microbial endocrinology when studying beef cattle health and performance.

Read the full article in the Journal of Animal Science.