Interpretive Summary: Impacts of L-glutamine in swine nursery diets

By: Anne Kamiya, MS

Stress from weaning and transport leads to poor piglet health outcomes such as diarrhea and increased susceptibility to infections. In the past, feeding prophylactic antibiotics prevented gastrointestinal disease and reduced piglet morbidity and mortality. Because of regulations to curb the use of antibiotics, there is an urgent need for safe and effective antibiotic alternatives. One such possibility is the supplement L-glutamine (GLN).

In this recent Journal of Animal Science study, researchers fed nursery pigs GLN or antibiotics and then compared their intestinal health and gut microbiomes. Weaned pigs that had just been transported were given a normal nursey diet with one the following for 14 days: (1) no supplementation, (2) supplementation with the antibiotic combo chlortetracycline and tiamulin, or (3) supplementation with 0.20% as-fed GLN. Samples of gut tissue and fecal matter were evaluated at 33 days (after pigs had already been reverted to normal diets for over two weeks). Results indicated that the microbiome composition of pigs fed antibiotics was distinct from animals fed the control or GLN diet, specifically, there was an increased amount of Lactobacillus bacteria in pigs fed antibiotics. Supplementation of GLN improved intestinal morphology compared to the control but had no impact on gap junction protein synthesis or inflammatory factors such as TNF-α.

Overall, the results of this study suggest that supplementation with GLN at 0.20% may have some benefit to the gut health of newly weaned and recently transported piglets, however, its effects are not comparable to antibiotics. Future studies evaluating whether increased GLN or a combination of GLN with other supplements or probiotics might have more benefit to the gut health of newly weaned and recently transported piglets may be useful. 

The original article, Replacing dietary antibiotics with 0.20% l-glutamine in swine nursery diets: impact on intestinal physiology and the microbiome following weaning and transport, this article is viewable in the Journal of Animal Science.