Stein, H. H. 2024. Review: Aspects of digestibility and requirements for minerals and vitamin D by growing pigs and sows. Animal 18, 101125. doi.org/10.1016/j.animal.2024.101125 Link to full text.

Espinosa Charmaine D., Leidy J. Torres-Mendoza, Jonathan R. Bergstrom, Hans H. Stein. 2024. Influence of a novel phytase on Ca and P digestibility in diets fed to sows in late-gestation and lactation. Animal Feed Science and Technology 309 (2024) 115906. doi.org/10.1016/j.anifeedsci.2024.115906. Link to full text.

Ibagon, Jimena A., Hans H. Stein, Charmaine D. Espinosa. 2023. Effect of Microbial Phytase on Digestibility of Phosphorus in Seven Sources of Sunflower co-Products Fed to Growing Pigs. J. Anim. Sci. Volume 101, Issue Supplement 2, Pages 303–304, doi.org/10.1093/jas/skad341.345. Link to abstract.

It is important that the digestibility of Ca in Ca sources is known to formulate diets based on values for digestible Ca rather than total Ca. Only a small amount of the Ca required by pigs is provided by plant-based ingredients and supplementation of Ca from Ca phosphates and Ca carbonate, is usually required to meet the requirement by pigs. In addition, use of microbial phytase increases Ca digestibility in Ca carbonate, which is one of the major sources of Ca in pig diets.

Differences in Ca digestibility in 4 sources of Ca carbonate produced in the United States have been observed, but it is unknown if there are differences in the ATTD of Ca in calcium carbonate sources produced outside the United States. Therefore, the objective of this experiment was to test the hypothesis that there are differences in the apparent total tract digestibility (ATTD) and standardized total tract digestibility (STTD) of Ca and in the response to microbial phytase among 20 sources of Ca carbonate obtained from different parts of the world.

Lee, Su A , Leidy J. Torres-Mendoza, and Hans H. Stein1. 2022. Effects of 25-hydroxycholecalciferol (25-OH-D3) and 1-hydroxycholecalciferol (1-OH-D3) on serum bone biomarkers and calcium and phosphorus balance and concentrations of energy in diets without or with microbial phytase fed to sows in late gestation. Journal of Animal Science, 2022, 100, 1–8. doi.org/10.1093/jas/skac299.

Field peas have been produced mainly for human consumption, but lastly, the industry has been included in diets fed to livestock due to its content of starch and protein. In diets for swine, only peas that are harvested at maturity are used. Almost 80% of P in non-oilseed legumes is bound to phytate, and pigs do not synthesize an adequate amount of endogenous phytate to liberate the P bound to phytate. Therefore, the digestibility of P in field peas is relatively low. Values for apparent total tract digestibility (ATTD) and standardized total tract digestibility (STTD) of P in field peas have been reported, but there are no comparative values for the ATTD and STTD of P among different varieties of field peas at different particle sizes. Therefore, the objective of this experiment was to test the hypothesis that there are no differences in the ATTD and the STTD of P among different sources of field peas fed to young pigs and the second hypothesis was that there is a linear increase in the ATTD and STTD of P as the particle size of field peas increases.

Lee, S. A, and H. H. Stein. 2022. Vitamin D and vitamin D metabolites impact on calcium and phosphorus balance in gestating sows. Proc. 21th Annual Midwest Swine Nutrition Conf. Danville, IN, Sep. 8, 2022. Pages 39-43. Link to full text.

Lee, Su A, and H. H. Stein. 2022. Digestibility of amino acids is not affected by increasing calcium from deficient to over-sufficient concentration in diets fed to pigs.15th International Symposium on Digestive Physiology of Pigs. Animal - Science Proceedings 13(Issue 2): 178 - 179. Link to abstract.

There are several factors related to dietary Ca that may influence digestibility of amino acids (AA). By chelating to dietary phytate, dietary Ca can form non-digestible Ca-phytate complexes, and this may result in reductions of P and AA digestibility. However, adding Ca to diets may increase activation of proteases as co-factors, which could result in increased AA digestibility. In contrast, pH in the digesta may be increased by adding Ca to diets, which likely will have a negative effect on activation of protein digesting enzymes. However, to our knowledge, no data demonstrating effects of increasing dietary Ca on digestibility of AA in pigs have been reported. Therefore, the objective of this experiment was to test the hypothesis that the concentration of Ca in diets affects apparent ileal digestibility (AID) of AA by pigs.