An amino acid produced naturally in people, swine and other species is showing promise as an alternative to antibiotics and growth promoters for piglets, according to the U.S. Department of Agriculture's Agricultural Research Service (ARS).

ARS scientists found that feeding L-glutamine to piglets produced positive growth and health effects. This news comes at an opportune time in light of the 2017 Veterinary Feed Directive banning the use of antibiotics in livestock diets for promoting growth.

Prior to the ban, producers used certain dietary antibiotics to improve the productivity of animals after stressful events such as weaning and transportation, according to Jay Johnson, an animal scientist at the ARS Livestock Behavior Research Unit in West Lafayette, Ind.

He and his colleagues investigated L-glutamine as a natural remedy to improve the intestinal health of piglets undergoing stress and to improve their welfare and productivity.

Some consumers take L-glutamine and the synthetic form, glutamine, as a supplement to counter the side effects of medical treatments, strengthen the immune system, prevent infections and improve digestive health, ARS said.

In piglets, stress can reduce immune function and leave the animals more susceptible to disease. Supplements that improve digestive health, nutrient absorption or intestinal microflora can help remedy these effects and improve the animal's welfare, according to Johnson.

In a study published in the Journal of Animal Science in 2017, Johnson and his team weaned and transported piglets and then fed them a dry feed diet formulated in one of the following three ways: mixed with dietary antibiotics, mixed with L-glutamine or mixed with no supplements.

According to the researchers, piglets on the L-glutamine diet had better growth and intestinal health than piglets in the other groups. Piglets on the L-glutamine diet ate 60% more food than the pigs in the other groups. Piglets that received neither dietary antibiotics nor L-glutamine had increased intestinal damage, reduced growth and increased behaviors associated with illness compared with piglets given antibiotics or L-glutamine.

ARS has filed a patent application for this technology.