ABSTRACT
The term ‘enteric health’ is becoming widely used, but is associated with a variety of meanings depending on the context in which it is used. It can be empirically and commercially defined as a physiological state promoting optimum growth over input, where performance provides the measure of enteric health. This is essentially a nutritional or metabolic definition, but the weight of evidence now suggests that growth and health are strongly affected by both the immune system and the types of bacteria resident within the intestine – the ‘microbiome’. These three domains – metabolism, the intestinal microbiome and the immune system – interact in complex ways to modify performance in growing pigs and provide important opportunities for interventions to improve pig production in the future. However, there are a number of confounding factors, such as welfare and disease state, that also need to be considered as desired outcomes when attempting to optimise gut health (Bailey, 2015). Thus, optimal enteric health under conventional, intensive husbandry may be different from that in outdoor systems, and very different from that in the expanding smallholder sector. It seems unlikely that a single definition or measure of enteric health status is universally applicable to all production systems, since different conditions during rearing are likely to result in different immune and metabolic systems arising from colonisation with a variety of intestinal bacterial species.
