As best practices regarding antibiotic use in veterinary medicine evolve and with the recent hype surrounding probiotics and microbiota, there is a large movement aimed at discovering the holy grail of food additives. Here we present a study that focused on improving piglet health. As individual litter sizes increase over time, so does the proportion of piglets with low birth weight. Research has shown that piglets that are underweight at weaning are more likely to become sick. Whereas plump piglets are more likely to have a healthy life. This complicates the study of the impact of food additives in two ways:
If we use food additives to prevent illness, how do we predict which animals will get sick and which animals will benefit the most from receiving these additives;
The measurable benefit in a healthy piglet might be subtle, even if it has a major long-term benefit for those that may get sick.
We understand that when we want to measure the effect of a treatment, it is easier and more convenient to focus studies on piglets most at risk, i.e. the underweight piglets.
CRIPA researchers Martin Lessard and Guylaine Talbot from Agriculture and Agri-Food Canada (Sherbrooke Research and Development Center) and Frédéric Guay (Université Laval) decided to study the immune and physiological responses of weaned piglets, separated into two categories based on their weight at weaning. As part of a collaboration that included molecular geneticist Nathalie Bissonnette (Sherbrooke Research and Development Center, Agriculture and Agri-food Canada) and Xian R. Jiang (University of Milan), the immune response and health profile of piglets were measured two weeks after weaning. The findings were then compared between piglets that were underweight or plump at weaning and those that had been challenged with bacteria.To identify a combination of food additives that can prevent infection, some piglets were given the antibiotic chlortetracycline or one of two combinations of food additives prior to being challenged with bacteria. The first combination of food additives contained increased levels of vitamins, natural substances with documented antimicrobial effects (cranberry extract and carvacrol) and prebiotics (derived from yeast enriched in mannans and glucans). The second combination contained all components of mixture 1 in addition to skimmed bovine colostrum.
The results showed that the most underweight piglets have the greatest inflammatory responses and must be monitored more closely than those that were plump and grew better in the first days of life. Additionally, underweight piglets whose feed was supplement with either combination of additives had decreased inflammatory responses that were similar to the inflammatory responses of piglets whose feed was supplemented with antibiotics.
Sources : Bissonnette N, Jiang XR, Matte JJ, Guay F, Talbot G, Bontempo V, Gong J, Wang Q, Lessard M. Effect of a post-weaning diet supplemented with functional feed additives on ileal transcriptome activity and serum cytokines in piglets challenged with lipopolysaccharide. Vet Immunol Immunopathol. 2016 Dec; 182:136-149.