Hans H. Stein

Read more about Reducing dietary protein in corn–soybean meal diets by reducing soybean meal and adding synthetic amino acids does not affect net energy or ileal starch digestibility, but increases ileal amino acid digestibility and reduces nitrogen retention

Effects of super-doses of phytase on standardized ileal digestibility of amino acids in soybean meal

Feed costs remain elevated and the environmental pressure on swine production continues to increase, which highlights the need for greater precision in diet formulation. Accurate estimation of digestible amino acids (AA) supplied by key ingredients such as soybean meal (SBM) is necessary to better match the AA requirements of pigs, improve nutrient utilization, and reduce nitrogen excretion. Microbial phytase is commonly included in diets for pigs because it hydrolyzes phytate, the primary storage form of P in oilseeds and cereal grains, thereby increasing the digestibility of P. In addition to improving P digestibility, phytase may also enhance AA digestibility in SBM-containing diets, although these responses have not been consistently observed. Recently, data from 5 experiments were summarized and it was concluded that ileal AA digestibility was improved by 3.7 to 4.5 percentage units if at least 1,000 units of phytase per kg diet was used. However, these data were based on mixed diets and responses specific to any ingredients were not reported, but because SBM is the major source of AA in diets for pigs, it is of interest to demonstrate the effectiveness of microbial phytase in the improvement of AA digestibility in SBM. Therefore, the objective of this experiment was to determine the ileal digestibility of AA in 3 sources of SBM supplemented with graded concentrations of microbial phytase. The first hypothesis was that increasing phytase inclusion would improve AA digestibility in SBM. The second hypothesis was that the response to phytase would not differ among the 3 sources of SBM.

Keywords:

Calcium, microbial phytase, Phosphorus, Soybean meal

Authors:

Jaramillo, Hernández, Lee, and Stein

Publication Type:

crystalline amino acids, nitrogen balance, reproductive performance, Sows, Soybean meal

Read more about Effects of super-doses of phytase on standardized ileal digestibility of amino acids in soybean meal

Reducing dietary crude protein for gestating and lactating sows reduces daily nitrogen retention, but reproductive performance is not impacted by diet protein concentration

Ibagon, Jimena A., Su A Lee, Hans H. Stein. 2026. Reducing dietary crude protein for gestating and lactating sows reduces daily nitrogen retention, but reproductive performance is not impacted by diet protein concentration. Journal of Animal Science and Biotechnology 7:125

Keywords:

Authors:

Ibagon, Lee, Stein

Publication Type:

Read more about Reducing dietary crude protein for gestating and lactating sows reduces daily nitrogen retention, but reproductive performance is not impacted by diet protein concentration

Increasing levels of phytase in corn-soybean meal diets increases the standardized total tract digestibility of Ca in soybean meal when fed to growing pigs

Calcium (Ca) is an essential macro mineral required for growth, bone development and remodeling, enzyme activity, cellular signaling, and metabolic regulation in swine (González-Vega and Stein, 2014). The concentration of Ca in diets and ingredients is a key feature because excess Ca decreases the digestibility of P and other nutrients and decreases feed intake and growth performance (Stein et al., 2011; Merriman et al., 2017; Lagos et al., 2019). Ideally, the requirement for Ca should be expressed as standardized total tract digestible (STTD) Ca instead of total Ca (NRC, 2012), which necessitates the generation of values for Ca digestibility in feed ingredients (Lautrou et al., 2020; Lee and Kong, 2022; Lee et al., 2023a). In plant feed ingredients, Ca concentration is low compared with inorganic sources; however, Ca in soybean meal (SBM) ranges from 0.25% to 0.75% (Sotak-Pepper et al., 2016; Lee et al., 2023a). Because SBM sometimes is included at high proportions in swine diets, Ca analysis of SBM is important to supplement diets with adequate quantities of additional Ca to meet requirements without including excess Ca in diets.

Keywords:

Calcium, microbial phytase, Phosphorus, Soybean meal

Authors:

Jaramillo, Hernández, Lee, and Stein

Publication Type:

microbial phytase, Growing pigs, Soybean meal

Read more about Increasing levels of phytase in corn-soybean meal diets increases the standardized total tract digestibility of Ca in soybean meal when fed to growing pigs

Inclusion of microbial phytase in diets for growing pigs

Jaramillo, B. M., A. V. Hernandez, S. A Lee, M. Cristobal, and H. H. Stein. 2026. Inclusion of microbial phytase in diets for growing pigs. National Hog Farmer. On-line edition. April 30, 2026. Link to full text.

Keywords:

Authors:

Jaramillo, Hernández, Lee, Cristobal, Stein

Publication Type:

Extension Reports and other non-refereed publications

Effects of graded levels of phytase on apparent total tract digestibility of energy and concentrations of digestible and metabolizable energy in soybean meal

Soybean meal (SBM) is commonly used as a source of amino acids in swine diets because of its high protein content (Kudelka et al., 2021). In addition, SBM contributes with energy and phosphorus (P). However, high portion of the P in SBM is bound to phytate, which is indigestible by pigs. Therefore, microbial phytase enzyme is supplemented in swine diets. The impact of phytase on the digestibility of P is well documented, however some experiments on digestibility in corn–SBM diets has been reported energy increase if microbial phytase was used (Liao et al., 2005; Arredondo et al., 2019; Lala et al., 2020; Espinosa et al., 2022), but, not in others (She et al., 2018; Mesina et al., 2019; Lamp and Moritz, 2022). There is, however, a lack of information about the impact of microbial phytase on the digestibility of energy in SBM. It is also not known if a possible effect of microbial phytase on energy digestibility in SBM is consistent among different sources of SBM.

Keywords:

Calcium, Digestible energy, Metabolizable energy, microbial phytase, Phosphorus, Soybean meal

Authors:

Jaramillo, Hernández, Lee, Stein

Publication Type:

digestibility; energy; fiber; growing pigs; pistachio shell powder; soybean hulls

Read more about Effects of graded levels of phytase on apparent total tract digestibility of energy and concentrations of digestible and metabolizable energy in soybean meal

Digestibility of Energy and Concentrations of Digestible and Metabolizable Energy in Pistachio Shell Powder and in Soybean Hulls Fed to Growing Pigs

Kim, Yeonwoo, Maryane S. F. Oliveira, Su A Lee, Hans H. Stein. 2026. Digestibility of Energy and Concentrations of Digestible and Metabolizable Energy in Pistachio Shell Powder and in Soybean Hulls Fed to Growing Pigs. Animals Animals 2026, 16, 758. doi.org/10.3390/ani16050758 Link to full text.

Keywords:

Authors:

Kim, Oliveira, Lee, Stein

Publication Type:

alternative ingredients, blood urea nitrogen, Dietary fiber, feed efficiency, pistachio shell powder, Weanling pigs

Pistachio shell powder may be included in diets for weanling pigs without compromising growth performance or blood characteristics

Kim, Yeonwoo, Su A Lee, and Hans H. Stein. 2026. Pistachio shell powder may be included in diets for weanling pigs without compromising growth performance or blood characteristics. Translational Animal Science, 2026, 10, txag002. doi.org/10.1093/tas/txag002 Link to full text.

Keywords:

Authors:

Kim, Lee, Stein

Publication Type:

Concentrations of digestible and metabolizable energy are greater in pistachio blanks than in wheat middlings, but some amino acids in pistachio blanks have reduced digestibility compared with soybean meal when fed to growing pigs

Kim, Yeonwoo, Su A Lee, Hans H. Stein. 2026.

Keywords:

Amino acids, Energy, Growing pigs, pistachio blanks, Wheat middlings

Authors:

Kim, Lee, Stein

Publication Type:

Read more about Concentrations of digestible and metabolizable energy are greater in pistachio blanks than in wheat middlings, but some amino acids in pistachio blanks have reduced digestibility compared with soybean meal when fed to growing pigs

Greenhouse gas emissions, net energy, and nitrogen balance are not impacted by inclusion of hybrid rye in diets for growing pigs, but ileal digestibility of amino acids and acid-hydrolyzed ether extract is reduced if hybrid rye replaces corn

Acosta, Jessica P., Su A Lee, Hans H. Stein. 2026.

Keywords:

Digestibility, Energy, greenhouse gas emission, nitrogen balance, Hybrid rye, Pigs

Authors:

Acosta, Lee, Stein

Publication Type:

microbial phytase, digestibility of P, digestibility of Ca, Growing pigs

Read more about Greenhouse gas emissions, net energy, and nitrogen balance are not impacted by inclusion of hybrid rye in diets for growing pigs, but ileal digestibility of amino acids and acid-hydrolyzed ether extract is reduced if hybrid rye replaces corn

Effects of a novel microbial phytase on digestibility of P and Ca in diets fed to young growing pigs

Introduction

Pigs have a poor utilization of phytate-bound P derived from plant feed ingredients and supplemental phytase is, therefore, often used in pig diets (Selle and Ravindran, 2008), which is a very effective way to increase P digestibility. However, digestibility of Ca is also increased by phytase (Lee et al., 2023).

Bestzyme has recently been developed as a novel phytase, but there is limited information on how this phytase works on P and Ca digestibility. Therefore, the objective of this experiment was to test the hypothesis that a novel microbial phytase can replace some of the dietary P and Ca in diets for growing pigs without negatively impacting the standardized total tract digestibility (STTD) of P and Ca.

Keywords:

Authors:

Mallea, Lee, Stein

Publication Type:

Extension Reports and other non-refereed publications

Read more about Effects of a novel microbial phytase on digestibility of P and Ca in diets fed to young growing pigs

Reducing dietary protein in diets for sows

Ibagon, J. A., H. H. Stein, and S. A Lee. 2026. Reducing dietary protein in diets for sows. National Hog Farmer. On-line edition. Jan. 29. 2026. Link to full text.

Keywords:

dietary protein, Diets, Sows

Authors:

Ibagon, Stein, Lee

Publication Type:

Effects of novel microbial phytases on growth performance and bone ash of young growing pigs

Pigs have a poor utilization of phytate-bound P derived from plant feed ingredients and thus supplemental phytase is used in pig diets (Selle and Ravindran, 2008). Use of phytase in diets has been a very effective way to increase P digestibility, but the digestibility of amino acids, energy, and other minerals may also be increased by super dosing phytase (Kies et al., 2006; Arredondo et al., 2019), which ultimately increases growth performance and bone ash of pigs.

Bestzyme has recently been developed as a novel phytase, but there is limited information on how this phytase works on growth performance and bone ash of pigs. Therefore, the objective of this experiment was to test the hypothesis that dietary P and Ca in diets for growing pigs can be reduced without negatively impacting growth performance and bone ash of pigs if Bestzyme phytase is included in the diets.

Keywords:

microbial phytase, Growth performance, Bone ash, Growing pigs

Authors:

Mallea, Lee, Stein

Publication Type:

Read more about Effects of novel microbial phytases on growth performance and bone ash of young growing pigs

Feeding intact protein from soybean meal instead of corn and synthetic amino acids does not affect growth performance, carcass composition, blood cytokines, or mRNA abundance of intestinal amino acid transporters in growing pigs, but net energy tends to b

Cristobal, Minoy, Su A Lee , Carl M. Parsons, and Hans H. Stein.

Keywords:

Amino acids, Carcass composition, Net energy, Pigs, Protein, Soybean meal

Authors:

Cristobal, Lee, Parsons, Stein

Publication Type:

Distillers dried grains with solubles, Net energy, nitrogen retention, Pigs, Starch

Read more about Feeding intact protein from soybean meal instead of corn and synthetic amino acids does not affect growth performance, carcass composition, blood cytokines, or mRNA abundance of intestinal amino acid transporters in growing pigs, but net energy tends to b

Determination of net energy and nitrogen balance in group-housed pigs fed diets containing varying levels of starch and fiber

Lee, S. A, and H. H. Stein. 2025. Determination of net energy and nitrogen balance in group-housed pigs fed diets containing varying levels of starch and fiber. J. Anim. Sci. 103(Supplement_3), 181-182. doi.org/10.1093/jas/skaf300.221 Link to abstract.

Keywords:

Authors:

Lee, Stein

Publication Type:

Greenhouse gas emission, nitrogen balance, and ileal digestibility of amino acids and acid hydrolyzed ether extract in diets containing different inclusion rates of hybrid rye fed to growing pigs

Acosta, J. P., S. A Lee, and H. H. Stein. 2025. Greenhouse gas emission, nitrogen balance, and ileal digestibility of amino acids and acid hydrolyzed ether extract in diets containing different inclusion rates of hybrid rye fed to growing pigs. J. Anim. Sci. 103(Suppl3), 186-187. doi.org/10.1093/jas/skaf300.224 Link to abstract.

Keywords:

Digestibility, greenhouse gas emission, Hybrid rye, Pigs

Authors:

Acosta, Lee, Stein

Publication Type:

Extension Reports and other non-refereed publications

Soybean meal remains a valuable pig feed ingredient

Cristobal, M., S. A. Lee, C. M. Parsons, and H. H. Stein. 2025. Soybean meal remains a valuable pig feed ingredient. National Hog Farmer, On-line edition, October 30, 2025. Link to full text.

Keywords:

Soybean meal, pig, feed ingredient

Authors:

Cristobal, Lee, Parsons, Stein

Publication Type:

Choice white grease equivalence of fat emulsifier in diets fed to growing pigs

Lee, S. A., V. Perez, H. Stein. 2025. Choice white grease equivalence of fat emulsifier in diets fed to growing pigs. Animal - Science proceedings, Volume 16, Issue 2, August 2025, Page 384 doi.org/10.1016/j.anscip.2025.07.166 Link to abstract.

Keywords:

Emulsifier, Equivalence, Fat

Authors:

Lee, Pérez, Stein

Publication Type:

Corn, pistachio shell powder, Weanling pigs

Effect of pistachio shell powder on growth performance of weanling pigs

Kim, Y. S. A. Lee, H. Stein. 2025. Effect of pistachio shell powder on growth performance of weanling pigs. Animal - Science proceedings, Volume 16, Issue 2, August 2025, Page 380. doi.org/10.1016/j.anscip.2025.07.156 Link to abstract.

Keywords:

Authors:

Kim, Lee, Stein

Publication Type: