Stein. Hans H. 2024. Net energy of soybean meal. J. Anim. Sci Vol. 102, Suppl. S2. P 184. doi.org/10.1093/jas/skae102.205 Link to the abstract.

Apparent ileal digestibility (AID) of amino acids (AA) is affected by dietary AA levels because of different contributions of endogenous AA to the ileal digesta from pigs fed diets with different levels of AA. Because of the influence of dietary protein and AA on calculated values for AID, values for AID obtained in individual feed ingredients are not always additive in mixed diets. Therefore, values for standardized ileal digestibility (SID) of AA, which are corrected for the basal ileal endogenous losses of AA, are used in diet formulations to avoid the influence of endogenous AA on digestibility values, and SID values are, therefore, additive in mixed diets.

When the direct procedure is used to determine AA digestibility, diets containing cereal grains are sometimes formulated to contain AA below the requirement. In contrast, if the SID of oilseed meals or other protein-rich ingredients are determined, concentrations of AA may be at or above the requirement. Because the influence of the basal endogenous losses of AA is eliminated in the calculations of SID values, it is assumed that values for SID are not influenced by dietary concentrations of AA. However, to our knowledge this hypothesis has not been experimentally verified, but it is an important question because it may influence how diets used in digestibility experiments are formulated. Therefore, four experiments were conducted to test the hypothesis that the SID of AA by growing pigs is not influenced by dietary AA levels.

Soybean meal (SBM) is the major source of amino acids (AA) and energy in diets for swine throughout the world. However, due to the emergence of feed-grade crystalline AA, it is estimated that SBM usage by pigs has been reduced by at least 35% over the last 25 years. Reduction on concentration of SBM and increasing the use of crystalline AA in diets may impact the digestibility of crude protein (CP) and AA. Therefore, the objective of this experiment was to test the hypothesis that diets containing corn, SBM, and crystalline AA have greater AA digestibility compared with corn and SBM diets.

Apparent ileal digestibility (AID) of crude protein (CP) and amino acids (AA) is affected by CP and AA concentrations in diets because of the different contributions of endogenous N and AA to the ileal digesta from pigs fed diets with different concentrations of CP. Because of the influence of dietary CP and AA on calculated values for AID, values for AID obtained in individual feed ingredients are not always additive in mixed diets if the concentration of CP and AA in the mixed diet is different from that of the ingredients. Therefore, values for standardized ileal digestibility (SID) of CP and AA, which are corrected for the basal ileal endogenous losses of CP and AA, are used in diet formulations to avoid the influence of endogenous AA on digestibility values, and SID values are, therefore, additive in mixed diets.

Espinosa, Charmaine D., M. S. F. Oliveira, J. K. Htoo, H. H. Stein. 2021. Concentrations of digestible amino acids in co-products from threonine and tryptophan fermentation are greater than in soybean meal. Animal Feed Science and Technology 277 (2021) 114948. doi.org/10.1016/j.anifeedsci.2021.114948. Link to full text.

Rundle, C. M., Y. Dersjant-Li, B. Hillen, M. S. F. Oliveira, and H. H. Stein. 2021. Buttiauxella Phytase Improves Growth Performance of Weanling Pigs Fed Corn, Soybean Meal, and Canola Meal Based Diets. J. Anim. Sci. 99(Suppl. 1): 49–50. doi.org/10.1093/jas/skab054.084. (Abstr.) Link to Absctract.

Soybean meal (SBM) is the major source of amino acids in diets for swine throughout the world. However, in addition to providing indispensable amino acids to diets, SBM also provides energy to the diets. Diets are often formulated based on the net energy (NE) in each individual ingredient using a linear programming computer software. Therefore, the NE for each ingredient is important for the value the ingredient is assigned in the formulation. However, the NE for SBM that is used by most feed formulators was generated many years ago, but results of recent research indicate that current U.S. SBM may provide more NE than previously estimated, which potentially results in an increased estimation of the value of SBM in diets for pigs. There is, therefore, a need for confirming or updating the NE value for SBM. As a consequence, the objective of this experiment was to test the hypothesis that the NE in U.S. SBM fed to modern genotypes of pigs is greater than the value that is currently used in feed formulation.

Espinosa, Charmaine D. , Maryane S. F. Oliveira, L. Vanessa Lagos, Terry L. Weeden, Aileen J. Mercado, and Hans H. Stein. 2020. Nutritional value of a new source of fermented soybean meal fed to growing pigs. Journal of Animal Science, 2020, Vol. 98, No. 12, 1–9. doi:10.1093/jas/skaa357. Link to full text.

Oliveira, Maryane S. F., John K. Htoo, and Hans H. Stein. 2020. The direct and difference procedures result in similar estimates for amino acid digestibility in feed ingredients fed to growing pigs. Journal of Animal Science, 2020, Vol. 98, No. 8, 1–8. doi:10.1093/jas/skaa225. Link to full text.