The majority of P in oilseed co-products is bound to phytate; however, pigs do not synthesize adequate amount of endogenous phytate to liberate the P bound to phytate and the digestibility of P in sunflower meal, therefore is low. Values for ATTD and STTD of P in sunflower meal (SFM) without and with phytase have been reported, but there are no comparative values for the ATTD and STTD of P in sunflower co-products produced in different parts of the world. Therefore, the objective of this experiment was to determine the ATTD and the STTD of P in different sources of sunflower co-products, and to test the hypothesis that regardless of source, microbial phytase increases the digestibility of P in sunflower co-products fed to young pigs.

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.

Lee, Su A, and H. H. Stein. 2022. Effects of Increasing Dose of a Novel E. coli Phytase on Total Tract Digestibility of Minerals and Energy in Pigs. J. Anim. Sci. 100(Suppl. 2): 36-37. doi.org/10.1093/jas/skac064.059. Link to Abstr.

Addition of probiotics to swine diets may improve gut health by modifying the microflora, which may help control pathogens, enhance immune response, and increase nutrient digestibility. Once consumed by the pig, probiotics enter the stomach where they are subjected to a low pH and pepsin. The Bacillus strain are metabolically inactive spores that are thermostable and survive at a low pH and, therefore, are thought to survive feed processing and digestion in the stomach. Addition of a Bacillus strain may enhance fermentation of dietary fiber in swine diets and, subsequently, increase the available energy from the diet in the form of volatile fatty acids. Bacillus strain also may degrade non-starch polysaccharides to reducing sugars that may serve as an energy source for the pig. A novel probiotic Bacillus toyonensis M15750 has been developed, but there are limited data to demonstrate the efficacy of this probiotic to increase nutrient digestibility. Therefore, an experiment was conducted to test the hypothesis that probiotic Bacillus toyonensis M15750 improve the apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of energy and nutrients when included in diets fed by weanling pigs.

Lee, Su A., and Hans H. Stein. 2022. Effects of dietary levels of calcium, phosphorus, and 1-alphahydroxycholecalciferol on digestibility, retention of calcium and phosphorus, and concentration of  metabolizable energy in diets fed to sows in late-gestation. Can. J. Anim. Sci. 102: 184–188 (2022) dx.doi.org/10.1139/cjas-2021-0018. Link to full text.

The physiological stage of pigs may influence total tract digestibility of nutrients because the digestibility of energy and some nutrients increases as body weight increases, but the impact of physiological stage may be greater for high-fiber diets than for diets with less concentration of fiber. Full fat rice bran (FFRB) and defatted rice bran (DFRB) are produced in the rice milling process and is available for animal feeding. However, because of the high concentration of dietary fiber, FFRB and DFRB may be better suited for diets fed to sows than for diets for weanling or growing pigs, but there is a lack of data on the digestibility of energy and nutrients in FFRB and DFRB fed to sows. Therefore, the objective of this experiment was to test the null-hypothesis that the apparent total tract digestibility (ATTD) of gross energy (GE), dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), and P in a corn-soybean meal diet and in diets containing FFRB or DFRB is not different between lactating sows and gestating sows if both groups are allowed to consume their diet on an ad libitum basis.

Espinosa, C. D., D. Velayudhan, Y. Dersjant-Li, J. Remus, H. H. Stein. 2021. Effect of phytase on mineral digestibility and growth performance of pigs fed diets with pharmacological levels of Zn. J. Anim. Sci. 99(Suppl. S3): 400-401. doi.org/10.1093/jas/skab235.727. Link to abstract.

Rapeseed is the second most produced oilseed in the world after soybean, and after the oil is extracted, a protein-rich meal is the resulting byproduct containing greater concentrations of sulfur amino acids (AA; i.e., Met and Cys) and Lys compared with legumes and cereal grains. Rapeseed proteins have great potential as a high-quality plant-based protein for humans due to their well-balanced AA profile, high metabolic utilization of protein, a protein digestibility corrected amino acid score (PDCAAS) similar to soy and milk proteins, and easily separable antinutritional factors. However, to our knowledge, digestible indispensable amino acid score (DIAAS) has not been determined for rapeseed protein isolate and the level of processing required to concentrate rapeseed into a protein isolate warrants further evaluation of its protein quality. Therefore, this experiment was conducted to test the hypothesis that heat treatment of rapeseed protein isolate will increase the digestibility of AA by growing pigs and result in a DIAAS that is comparable to soy and animal protein isolates.

Lee, S. A., M. R. Bedford, H. H. Stein. 2021. Comparative digestibility and retention of calcium and phosphorus in normal- and high-phytate diets fed to gestating sows and growing pigs. Animal Feed Science and Technology 280 (2021) 115084. doi.org/10.1016/j.anifeedsci.2021.115084. Link to full text.