Most of the P in corn and soybean meal (SBM) is stored as phytate. Phytase consists of one hydroxylated inositol ring with six phosphate groups. Therefore, phytase is often included at a standard level of 500 units (FTU) per kg in swine diets to increase the release of P from phytate. However, greater concentrations of phytase in diets for pigs may benefit growth and feed efficiency, which is likely a result of the inositol that is also released and can be absorbed by pigs. Inositol is believed to increase growth of animals by stimulating protein accretion. Inositol also improves gut health of pigs by enhancing intestinal epithelial cell functions. However, data from recent research demonstrated that weaning pigs at around 21 days of age results in a dramatic drop in plasma inositol and it is not until 6 weeks post-weaning that pigs will regain preweaning levels of inositol. Therefore, an experiment was conducted to test the hypothesis that microbial phytase will release sufficient inositol from corn and SBM and other ingredients in diets for newly weaned pigs to maintain pre-weaning levels of plasma inositol throughout the post-weaning phase and that this will result in improved growth performance of pigs.

Cristobal, Minoy, Su A Lee, Leidy J. Torres-Mendoza, Andrea P. Mallea, Carl M. M. Parsons, Hans H. Stein. 2024. Effect of feeding intact protein from soybean meal instead of crystalline amino acids on energy and nitrogen balance by growing pigs. J. Anim. Sci Vol. 102, Suppl. S2. P 283 - 284. doi.org/10.1093/jas/skae102.322. Link to abstract.

Mallea, Andrea P., Su A Lee, Minoy Cristobal, Leidy J. Torres-Mendoza, Hans H. Stein. 2024. Supplementation of valine, isoleucine, and tryptophan may overcome the negative effects of dietary excess leucine in high protein corn protein when fed to weanling pigs. J. Anim. Sci. Vol. 102, Suppl. S2. P 34 - 35. doi.org/10.1093/jas/skae102.041 Link to abstract.

High protein corn protein (HPCP) is a corn co-product derived from the ethanol industry that contains between 40 and 50% crude protein, and therefore, may be used in diets for pigs as a source of amino acids (AA). However, such diets will contain more than twice as much Leu as recommended and there is a negative relationship between dietary Leu and brain synthesis of serotonin, which results in reduced feed intake of pigs fed diets containing excess Leu. There is also a reduced protein synthesis because of increased Val and Ile metabolism due to excess dietary Leu. As a consequence, pigs often have reduced growth performance if fed diets with high concentrations of HPCP. However, it may be possible to counteract the negative effects of the high Leu concentrations in corn co-products by adding crystalline sources of Trp, Val, and Ile to the diets and it may, therefore, be possible that HPCP can be used in diets without influencing growth performance or intestinal health of weanling pigs. Therefore, the hypothesis that HPCP may be used as the primary source of AA in diets for weanling pigs if diets are fortified with crystalline AA was tested. 

Mallea O., A. P., M. S. F. S. Oliveira, D. A. Lopez D., H. H. Stein. 2022. Nutritional Value of a New Source of Cheese Co-Product Fed to Weanling Pigs. J. Anim. Sci. 100(Suppl. 2): 174. doi.org/10.1093/jas/skac064.296. Link to Abstr.