Lancheros, Paola, Vanessa Lagos, Hans H Stein. 2020. Enhanced torula yeast has increased nutritional value compared to fish meal when fed to weanling pigs. J. Anim. Sci.  98(Suppl. 3): 62. doi.org/10.1093/jas/skaa054.112. (Abstr.). Link to abstract.

Microbial phytase is usually included in diets for pigs to increase P absorption and utilization by hydrolyzing phytate within the gastrointestinal tract of pigs. High doses of phytase (i.e., > 1,000 FTU/kg) is also hypothesized to increase release of nutrients other than P due to increased degradation of phytate. A next generation biosynthetic bacterial 6-phytase (PhyG; DuPont Animal Nutrition) may increase digestibility of nutrients in diets for pigs; however, there are no data to demonstrate the efficacy of this phytase. Therefore, an experiment was conducted to test the hypothesis that the negative impact of phytate is reduced at higher phytase doses. It was also the objective of this research to test the hypothesis that inclusion of increasing levels of phytase increases bone ash and apparent total tract digestibility (ATTD) of minerals in diets containing varying phytate concentrations.

Rodriguez, Diego A., Su A Lee, and Hans H. Stein. 2020. Digestibility of amino acids, but not fiber, fat, or energy, is greater in cold-fermented, low-oil distillers dried grains with solubles (DDGS) compared with conventional DDGS fed to growing pigs. Journal of Animal Science, 2020, Vol. 98, No. 10, 1–8. doi:10.1093/jas/skaa297.

In most AA digestibility experiments collection bags are changed at least every 30 min and the collected ileal digesta are stored at –20 °C to prevent microbial degradation of proteins. Other attempts to reduce microbial activity in digesta include adding acids to collection bags to reduce the pH in ileal digesta. Acids may also be added to collection pitchers. However, in some experiments, no attempt to reduce pH is made because it is assumed that the rapid reduction in temperature after collection is sufficient to prevent microbial degradation of proteins.

To our knowledge, there is, however, no information about the necessity of adding acids to collected digesta and it is not known if values for apparent ileal digestibility (AID), basal endogenous losses of AA, or standardized ileal digestibility (SID) of AA are influenced by addition of acids to digesta. Therefore, the objective of this experiment was to test the null-hypothesis that values for AID, basal endogenous losses, and SID of AA are not influenced by addition of acids to ileal digesta collection bags or to collection pitchers.

Absorption of Ca and P by active transport in the small intestine is regulated by calcitriol, which is the active form of vitamin D (1,25-dihydroxycholecalciferol) and the hormones calcitonin and PTH. One-alpha-hydroxycholecalciferol (1-α-OH-D₃) is an active vitamin D₃ analog that does not require the second hydroxylation step for vitamin D₃ to be active. It is possible that supplementation of 1-α-OH-D₃ may increase absorption of Ca and P.

The requirement for Ca and P by gestating sows increases in late gestation compared with early- and mid-gestation because of increased needs by the developing fetuses. It is also possible that dietary concentrations of Ca and P affect the rate of absorption of Ca and P in sows but data to demonstrate this have not been reported. Therefore, the objective of this experiment was to test the hypothesis that the Ca and P concentrations in diets fed to gestating sows in late gestation and supplementation of 1-α-OH-D₃ affect apparent total tract digestibility (ATTD) and retention of Ca and P as well as the ATTD of GE and concentration of DE in diets. The second hypothesis was that there is an interaction between dietary Ca and P concentrations and supplementation of 1-α-OH-D₃ in diets fed to gestating sows.

Lancheros, J. P., C. D. Espinosa, H. H. Stein. 2020. Effects of particle size reduction, pelleting, and extrusion on the nutritional value of ingredients and diets fed to pigs: A review. Animal Feed Science and Technology 268 (2020) 114603. https://doi.org/10.1016/j.anifeedsci.2020.114603.

Kim, Beob G., Su A Lee, Kyu R. Park, and Hans H. Stein. 2020. At least 3 days of adaptation are required before indigestible markers (chromium, titanium, and acid insoluble ash) are stabilized in the ileal digesta of 60-kg pigs, but values for amino acid digestibility are affected by the marker. Journal of Animal Science, 2020,  Vol. 98: No.

Lee, Su A.,  L. Vanessa Lagos, Mike R. Bedford, and Hans H. Stein. 2020. Increasing calcium from deficient to adequate concentration in diets for gestating sows decreases digestibility of phosphorus and reduces serum concentration of a bone resorption biomarker. Journal of Animal Science, 2020,  Vol. 98: No. 3:1-8.