Inflammation: friend or foe for animal production?

Inflammation is an essential immune response that seeks to contain microbial infection and repair damaged tissue. Increased pro-inflammatory mediators have been associated with enhanced resistance to a range of important poultry and pig pathogens. However, inflammation may also have undesirable consequences, including potentially exacerbating tissue damage and diverting nutrients away from productive purposes. The negative effects of inflammation have led to the active pursuit of anti-inflammatory feed additives and/or strategies. These approaches may, however, impair the ability of an animal to respond appropriately and effectively to the array of pathogens that are likely to be encountered in commercial production, and specifically young animals who may be particularly reliant on innate immune responses. Thus, promoting an animal's capacity to mount a rapid, acute inflammatory response to control and contain the infection and the timely transition to anti-inflammatory, tissue repair processes, and a homeostatic state are suggested as the optimum scenario to maintain an animal's resistance to pathogens and minimize nonproductive nutrient losses. Important future studies will help to unravel the trade-offs, and relevant metabolic pathways, between robust immune defense and optimum productive performance, and thus provide real insight into methods to appropriately influence this relationship.