Death loss associated with bovine respiratory disease (BRD) has continued to rise in recent decades, and as such, new approaches should be sought to mitigate BRD. Research suggests that the predisposing factors of gut barrier dysfunction (GBD) are like BRD in that they can both be triggered and aggravated by stress events, thus, they may occur simultaneously. GBD describes a disease state in the gastrointestinal tract that increases the exposure of blood circulation to microorganisms that naturally reside in the small intestine, resulting in inflammation. Gut health may affect disease outcomes because the gastrointestinal barrier is the body’s largest immune organ, and supporting the immune response imposes a significant energetic cost. This energetic burden that GBD imposes on the body should be considered in terms of its ability to affect overall health outcomes. In this experiment, heifers were (GBD group) or were not (control group) subjected to a protocol that induced GBD. All heifers were then subjected to a respiratory disease challenge, and important indicators of the immune response were measured. Heifers with increased gut permeability exhibited a decreased febrile response, which may suggest a less robust early immune activation, as fever is an important part of the normal response to infection. These heifers also displayed altered acute‑phase protein production, which may influence how efficiently cattle can control and recover from infection. These results suggest that gut health may play a significant role in overall cattle immunity and should be given greater consideration in the effort to improve disease outcomes.

Read the full article in the Journal of Animal Science.