Trace Mineral Solubility and Digestibility in the Small Intestine of Piglets Are Affected by Zinc and Fibre Sources

Abstract

Findings that Zn and fibre source affected the nutrient apparent total tract digestibility (ATTD), made us hypothesize that interactions could occur affecting the apparent digestibility of Zn and trace elements (TEs) interacting with Zn in the digestive tract. Therefore, the study investigated the effects of Zn and fibre sources on the apparent digestibility and solubility of TEs (Zn, Cu, Fe, Mn) and pH in the small intestinal segments of 40-days-old piglets. In vitro solubility of TEs was estimated using a simulated digestion assay. Feed supplementation with potato fibre (PF) affected the ATTD of all TEs and dry matter as well as mineral solubility in the ileum and/or jejunum without any effect on pH in the small intestine. Intake of PF enhanced Zn and Cu absorption (p < 0.01), but significantly decreased ATTD of Fe and Mn (p < 0.001). Diet supplementation with Zn glycinate decreased Zn absorption in the gut (p < 0.01) and affected the solubility of other TEs in the different digestion phases. Although in vitro solubility of TEs does not provide a good prediction of mineral bioaccessibility, using a combination of in vitro and in vivo methods can enable prediction of the trace mineral absorption.