Jaramillo

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: 
Research Reports

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: 
microbial phytase, Growing pigs, Soybean meal
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: 
Research Reports

Additive effects of 25-hydroxy-vitamin D3 and microbial phytase on digestibility of calcium and phosphorus, blood vitamin D>3 metabolites, and bone biomarkers in growing pigs

Jaramillo, Bibiana M., Su A Lee, Jessica P. Acosta, Hans H. Stein. 2025. Additive effects of 25-hydroxy-vitamin D3 and microbial phytase on digestibility of calcium and phosphorus, blood vitamin D>3 metabolites, and bone biomarkers in growing pigs. Journal of Animal Science, Volume 103, Issue Supplement_1, May 2025, Pages 151–152, doi.org/10.1093/jas/skaf102.162 Link to abstract.

Keywords: 
Calcifediol, Phytase, swine
Authors: 
Jaramillo, Lee, Acosta, Stein
Publication Type: 
Abstracts

25-hydroxy-vitamin D3 and microbial phytase may increase digestibility of calcium and phosphorus in diets fed to growing pigs

Vitamin D regulates a wide spectrum of genes responsible for Ca and P homeostasis and cell differentiation. Cholecalciferol, commonly known as vitamin D3, is a primary source of vitamin D3 in diets for growing pigs; however, it needs to be hydroxylated twice to be active. The first hydroxylation occurs in the liver at the 25-position, resulting in 25-hydroxycholecalciferol [25(OH)D3], whereas the second hydroxylation occurs in the kidneys at the 1-position, resulting in 1,25 dihydroxycholecalciferol [1,25(OH)2D3], which is the active form of vitamin D3 in the body. Supplementation of 25(OH)D3 to diets for sows in late gestation may increase the apparent total tract digestibility (ATTD) and retention of Ca and P, but there are no data to demonstrate this effect in growing pigs.

Cereal grains commonly used in diets for pigs have low digestibility of P because P is bound to phytate. Exogenous phytase increases the digestibility of both Ca and P in pigs by releasing the P from the phytate molecule within the gastrointestinal tract of pigs. However, there is limited information about the interaction between 25(OH)D3 and supplemental phytase in diets fed to growing pigs. Therefore, the objective of this experiment was to test the hypothesis that both 25(OH)D3 and microbial phytase independently and in combination may increase standardized total tract digestibility (STTD) of Ca and P by growing pigs.

Keywords: 
Calciferol, Calcium, Phosphorus, Phytase, Vitamin D, Vitamin D Metabolites
Authors: 
Jaramillo, Lee, Acosta, Stein
Publication Type: 
Research Reports