PSXIII-B-8 - Effect of Supplemental Myo-inositol on Growth Performance and Apparent Total Tract Digestibility of Weanling Piglets Fed Reduced Protein Diets and Intestinal Cell Epithelial Barrier Integrity

Abstract: Myo-inositol is a breakdown product of phytate produced in the gut through the action of phytase. Although the effect of phytase-released phosphorus on growth performance of animals has been well characterized, there is still little understanding of myo-inositol effects. The objectives of this study was to determine the effects of added myo-inositol to a phytate-rich low-protein diet on growth performance and apparent total tract digestibility (ATTD) in growing piglets as well as to determine whether myo-inositol could directly affect intestinal epithelial cell proliferation and function in intestinal porcine epithelial cells (IPEC-J2). A total of 128 weanling piglets were allotted to four dietary treatments consisting of eight replicates per treatment and four piglets per replicate in a randomized complete block design for four weeks. The experimental diets comprised the positive control (PC; 20% crude protein (CP), negative control (NC; 17% CP), negative control plus 2.0g/kg myo-inositol (NC+INO; 17% CP) and negative control plus 3000FTU/kg phytase (NC+PHY; 17% CP). Weekly average daily feed intake (ADFI), average daily gain (ADG), gain-feed ratio (G: F) were recorded. Phytase supplementation in the protein-deficient NC diet increased the G:F ratio (P< 0.05) without myo-inositol effect on growth performance. Phosphorus digestibility in the phytase supplemented group increased compared to the PC, NC, and NC+INO groups whereas plasma myo-inositol concentration was significantly higher (P< 0.05) in the NC+INO group. Due to lack of myo-inositol effect on growth performance, an additional in vitro study was conducted to determine direct effect of myo-inositol on the intestinal epithelium that might not be reflected in growth performance. Myo-inositol increased mRNA abundance of selected nutrient transporters in a concentration-dependent manner (P< 0.05), enhanced barrier integrity in the IPEC-J2 monolayer and reduced paracellular permeability of FITC-dextran (P< 0.05). In conclusion, despite the lack of myo-inositol effect on animal performance, the in-vitro data indicates that myo-inositol may directly regulate gut barrier integrity.