A new source of soy protein concentrate (SPC) can be used in diets fed to weanling pigs without negatively affecting the digestibility of energy or nutrients, according to research conducted at the University of Illinois.
“Soy protein concentrate is typically produced by using an alcohol extraction process to remove soluble carbohydrates from soybean meal," said Hans H. Stein, University of Illinois professor of animal sciences. "However, a new soy protein concentrate has been developed that combines a non-alcohol extraction process with enzymatic treatment of soybean meal."
Stein and visiting scholar Maryane S. Oliveira conducted three experiments to evaluate the nutritional value of this new SPC product.
The SPC contained 61.2% crude protein, compared with approximately 47.7% for dehulled soybean meal. The standardized ileal digestibility of isoleucine and leucine and some dispensable amino acids was greater in SPC than in soybean meal, but for crude protein and most amino acids, no difference was observed between SPC and soybean meal, Stein reported.
SPC contained 3,479 kcal/kg of digestible energy and 3,299 kcal/kg of metabolizable energy, compared with soybean meal's levels of 3,319 kcal and 3,093 kcal, respectively.
Removal of oligosaccharides — which weanling pigs cannot digest — and other soluble carbohydrates from soybean meal resulted in an increased concentration of crude protein, which is likely the reason for the greater concentration of digestible energy in the novel SPC, he said.
There was no difference in the standardized total tract digestibility of phosphorus between SPC and soybean meal, but for both ingredients, the addition of microbial phytase increased phosphorus digestibility by about 35%.
"Soy protein concentrate is one way of feeding high-quality soy protein to weanling pigs," Stein said. "This new technology produces soy protein concentrate that is high in digestible amino acids and energy."
Funding for this research was provided by Midwest Ag Enterprises Inc. of Marshall, Minn.
The paper, "Digestibility of Energy, Amino Acids & Phosphorus in a Novel Source of Soy Protein Concentrate & in Soybean Meal Fed To Growing Pigs," was published in the August issue of the Journal of Animal Science. The full text can be found online at https://www.animalsciencepublications.org/publications/jas/articles/94/8/3343.