Lagos, L. V. and H. H. Stein. 2017. Chemical composition and amino acid digestibility of soybean meal produced in the United States, China, Argentina, Brazil, or India. J. Anim. Sci. 95(Suppl. 5):93 (Abstr.) Link to abstract (.pdf)

C. Pedersen, C, J. S. Almeida, and H. H. Stein. 2016. Analysis of published data for standardized ileal digestibility of protein and amino acids in soy proteins fed to pigs. J. Anim. Sci. 94(Suppl. 3):340-343. Link to full text (.pdf)

Oliveira, M. S. and H. H. Stein. 2016. Digestibility of energy, amino acids, and phosphorus in a novel source of soy protein concentrate and in soybean meal fed to growing pigs. J. Anim. Sci. 94:3343-3352. Link to full text (.pdf)

Kiarie, E., Y. Liu, M. C. Walsh, H. H. Stein, and L. Payling. 2016. Xylanase responses on apparent ileal digestibility of nutrients, fiber and energy in growing pigs fed corn, 30% corn co-products and soybean meal based diets as influenced by microbial phytase and acclimatization period. J. Anim. Sci. 94(Suppl. 2):112-113 (Abstr.) Link to abstract (.pdf)

Sotak-Peper, K. M., J. C. González-Vega, and H. H. Stein. 2015. Concentrations of digestible, metabolizable, and net energy in soybean meal produced in different areas of the United States and fed to pigs. J. Anim. Sci. 93:5694-5701. Link to full text (.pdf)

Soybean meal is the main protein source used in diets for pigs in the United States, as well as most countries of the world, due to the high quality of the protein it provides. However, soybean meal also contains antinutritional factors that limit its use in weanling pig diets. Pigs do not secrete the enzyme needed for the hydrolysis of raffinose and stachyose, α-galactosidase, in the small intestine. Therefore, these oligosaccharides are not enzymatically digested, but are instead fermented in the small and large intestines. This results in decreased growth performance and increased incidence of diarrhea when fed to weanling pigs.

Oligosaccharides can be removed from soybean meal using an alcohol extraction process, creating soy protein concentrate. Soy protein concentrate has greater digestibility of most amino acids and greater concentrations of digestible energy (DE) and metabolizable energy (ME) than soybean meal. A new source of soy protein concentrate called Nutrivance (Midwest Ag Enterprises Inc., Marshall, MN) has recently been introduced, which is produced using a process combining non-alcohol extraction and enzymatic treatment of soybean meal. The nutritional value of soy protein concentrate produced using this method has not been determined. Therefore, an experiment was conducted to determine the concentrations of DE and ME in soy protein concentrate and to compare these values to DE and ME in soybean meal.

Soybean meal is a high quality source of protein in diets fed to pigs. However, soybean meal contains anti-nutritional factors such as trypsin inhibitors and oligosaccharides, which decrease nutrient availability and limit the amount of soybean meal that can be fed in weanling pig diets.

Soy protein concentrate is produced by processing soybean meal to remove some nonprotein components, including the soluble carbohydrates. This leaves soy protein concentrate with a greater concentration of crude protein and amino acids than soybean meal. The presence of oligosaccharides in soybean meal has been shown to reduce the tolerance of young pigs to conventional soybean meal, and therefore, animal proteins rather than soybean meal is often used in diets for young pigs. However, if the oligosaccharides and other antinutritional factors can be removed from soybean meal, it is possible to use soybean meal in diets for young pigs instead of animal proteins.

Typically, an alcohol extraction process has been used to remove soluble carbohydrates from soybean meal to create soy protein concentrate. However, a new source of soy protein concentrate called Nutrivance (Midwest Ag Enterprises Inc., Marshall, MN) has recently been introduced. Nutrivance is produced using a process combining non-alcohol extraction and enzymatic treatment of soybean meal. The nutritional value of soy protein concentrate produced using this method has not been determined. Therefore, an experiment was conducted to determine the digestibility of amino acids in this new source of soy protein concentrate.

Soybeans grown in the northern United States are exposed to fewer growing days and hours of sunlight than soybeans grown elsewhere in the U.S. As a result, soybeans grown in the northern U.S. fix less nitrogen, and have a lower concentration of crude protein, than other U.S. soybeans. However, the concentrations of particular amino acids, particularly indispensable amino acids, are more important for the purposes of diet formulation than the concentration of crude protein. The concentration of amino acids in soybeans grown in different parts of the U.S. has not been determined.

The amount of amino acids in soybean meal that are available to the pig also depends on digestibility, but no research has been conducted to compare the digestibility of amino acids among soybean meal produced in different regions of the U.S. Therefore, an experiment was conducted to compare the standardized ileal digestibility (SID) of amino acids and the concentration of SID amino acids in soybean meal produced in different regions within the United States and fed to growing pigs.

Berrocoso, J. D., O. J. Rojas, Y. Liu, J. Shoulders, J. C. González-Vega, and H. H. Stein. 2015. Energy concentration and amino acid digestibility in high-protein canola meal, conventional canola meal, and soybean meal fed to growing pigs. J. Anim. Sci. 93:2208-2217. Link to full text (.pdf)