This past week I participated in both the Leman Swine Health Conference and the Minnesota Nutrition Conference. At both meetings one of the major topics was ‘gut health’ and the impact of nutrition on health.
It was exciting to listen to the next generation of scientists take us through the basics of gut physiology and the defensive mechanisms of the gut. Their level of understanding of how the biome (the sum of all bacteria in the intestinal tract) impacts the activation of immune systems, impacts the availability of nutrients, etc. was astounding. For example, we learned that in turkeys, bacteria appear in the intestinal tract in a specific order and the hatchery where the birds come from is a predictor of how soon these bacteria appear and subsequent overall growth performance.
These types of presentations led to much hallway discussion about the interaction of nutrition and disease. Can we set up the gut prior to a challenge by feeding a specific ingredient at a specific point in the pigs life? Why do PRRS positive pigs grow faster/better on diets with higher amounts of soybean meal, even when they are balanced to the same levels of energy, SID amino acids, etc? Does butyrate (a volatile fatty acid produced by bacterial fermentation in the large intestine) really result in a better immune response when the pig is faced with an intestinal challenge?
To me this is exciting stuff when you consider that in high school vo-ag and even introductory animal nutrition courses in college we spent time learning to balance rations using the Pearson Square with the goal being to provide the animal with crude protein. In the 70’s and early 80’s extension nutritionists talked about formulating diets with soybean meal versus HogCon-40 products (both were excellent sources of amino acids). The University of Nebraska Swine Nutrition Guide began talking about synthetic lysine additions to diets in 1981 and today we routinely add up to 4 synthetic amino acids to our formulas.
We can expect future diets to not only be based on SID estimated requirements but possibly immune activation requirements and other growth enhancing responses we have yet to discover. As one nutritionist commented – gone are the days of assuming all pigs only needed corn-soy diets. The nutritionist of the future will think about leaky gut (a breakdown in lumen of the gut that allows harmful organisms and undesired products of digestion to enter the body), health of the mucosal surface, intestinal structure as it relates to overall health of the population of pigs in the barn or system, etc.