Within the last 20 years, soybean meal (SBM) inclusion levels in pig diets have become heavily dependent on pricing. This is at the detriment of overlooking the value of SBM beyond its primary attributes as a source of amino acids. Shifting diets to higher inclusion levels of crystalline amino acids and distillers dried grains with solubles (DDGS) — a 35% increase between 2000 and 2017 — hinders soy’s beneficial components, such as isoflavones, saponins and phenolic antioxidants. These vital compounds improve immune responses, provide anti-inflammatory benefits and enhance growth performance of pigs exposed to viral disease challenges.
Presented at the International Conference on Swine Nutrition on Aug. 11, results from a soy checkoff-funded study, “Evaluation of the Potential Benefit of Soybean Meal on Gain and Feed Efficiency of Growing Pigs,” among several other independently evaluated, unbiased studies confirmed an economic return and direct and positive relationship between SBM and improved total weight gain and feed use efficiency in developing pigs. The publicly available capstone study also revealed that soy’s health benefits are more pronounced when swine experience respiratory health challenges, which could be of greater importance during summer months when the average daily gain is important to achieve market weights.
“This checkoff-supported study points out that formulating for least cost doesn’t always add up to maximum profit, especially in the volatile commodity markets that face the swine sector right now,” said Dean Boyd, Ph.D., a consulting animal nutritionist, adjunct professor of animal nutrition at North Carolina State University and Iowa State University, and a principal investigator for the study. “With pricing as the dominant factor driving ingredient decisions, little consideration is given to the intrinsic value of soybean meal, which offers an essential source of health-promoting compounds and amino acids.”
In a recent article in National Hog Farmer, Eric van Heugten, Ph.D., at North Carolina State University, who’s a collaborator on the project, reported that grower pigs starting at about 85 pounds fed a reduced SBM diet had a 2.46-pound lower body weight at the end of the study compared to pigs fed the higher SBM diet, even after balancing for amino acids. And replacing SBM with lysine·HCl (plus other crystalline amino acids) reduced final body weight by 5.71 pounds.