Amino Acid Helps Shore Up Defenses of Swine

Nov 20, 2020

West Lafayette, Indiana — A third round of feeding trials conducted by a team of USDA Agricultural Research Service (ARS) and university scientists has again shown that a dietary supplement called L-glutamine can naturally promote growth and wellness in pigs.

Jay S. Johnson, an animal scientist with ARS's Livestock Behavior Research Unit in West Lafayette, Indiana, and his Purdue University collaborators are investigating L-glutamine as a natural alternative to using dietary antibiotics. Swine producers had used antibiotics to help piglets cope with stressful events like being weaned from their mothers and then transported, which can lower young animals' immune function, feed intake and growth.

However, a 2017 Veterinary Feed Directive restricted the practice amid concerns it contributed to antimicrobial resistance to medically important antibiotics used to treat human infection. The team's investigation of L-glutamine, a naturally occurring amino acid found in the body and in food, is part of a broader research effort to identify suitable replacements that are just as effective, safe and economical to use.

The latest study is an expansion of trials conducted in 2017 and 2018. As before, groups of piglets were weaned and then transported for 12 hours, simulating what they might experience in a commercial operation. After transport, the piglets were housed in a nursery barn. This time, the researchers supplemented the young animals' diets for 14 days with L-glutamine at one of five feed concentrations: 0.20, 0.40, 0.60, 0.80 or 1.00 percent. Another group of piglets also received feed with antibiotics (chlortetracycline and tiamulin) but no supplemental L-glutamine, and a final group received a non-supplemented diet.

Highlighted results of a paper published in Translational Animal Science are below:

As with prior trials, L-glutamine-treated pigs performed similarly to those in the antibiotics group, and both of these groups fared better than piglets given non-supplemented feed.

The study results indicate that the increased weight gain and other benefits of treating piglets with L-glutamine above the original .20 percent test can be as profitable as using dietary antibiotics.

0.40 percent L-glutamine was the optimal supplementation level for improving pig welfare and performance immediately after weaning and transport, while 0.80 percent appeared to offer the most long-term economic benefit.

The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.

Source : ars.usda.gov

Video: US Soy: Pig growth is impaired by soybean meal displacement in the diet

Eric van Heugten, PhD, professor and swine extension specialist at North Carolina State University, recently spoke at the Iowa Swine Day Pre-Conference Symposium, titled Soybean Meal 360°: Expanding our horizons through discoveries and field-proven feeding strategies for improving pork production. The event was sponsored by Iowa State University and U.S. Soy.

Soybean meal offers pig producers a high-value proposition. It’s a high-quality protein source, providing essential and non-essential amino acids to the pig that are highly digestible and palatable. Studies now show that soybean meal provides higher net energy than current National Research Council (NRC) requirements. Plus, soybean meal offers health benefits such as isoflavones and antioxidants as well as benefits with respiratory diseases such as porcine reproductive and respiratory syndrome (PRRS).

One of several ingredients that compete with the inclusion of soybean meal in pig diets is dried distillers grains with solubles (DDGS).

“With DDGS, we typically see more variable responses because of the quality differences depending on which plant it comes from,” said Dr. van Heugten. “At very high levels, we often see a reduction in performance especially with feed intake which can have negative consequences on pig performance, especially in the summer months when feed intake is already low and gaining weight is at a premium to get them to market.”

Over the last few decades, the industry has also seen the increased inclusion of crystalline amino acids in pig diets.

“We started with lysine at about 3 lbs. per ton in the diet, and then we added methionine and threonine to go to 6 to 8 lbs. per ton,” he said. “Now we have tryptophan, isoleucine and valine and can go to 12 to 15 lbs. per ton. All of these, when price competitive, are formulated into the diet and are displacing soybean meal which also removes the potential health benefits that soybean meal provides.”