Effects of Zinc Sources and Levels on Growth Performance, Zinc Status, Expressions of Zinc Transporters, and Zinc Bioavailability in Weaned Piglets

Abstract

The present study was conducted to explore the bioavailability of chitosan–zinc chelate (CS–Zn) in weaned piglets, and its characteristics of prepared and oral safety were also involved. A total of 210 crossbred weaned piglets (Duroc × Landrace × Large White) with a mean body weight of 6.30 kg were randomly assigned into seven dietary treatments involving a 2 × 3 factorial arrangement with two Zn sources (CS–Zn and ZnSO4) and three levels of added Zn (50, 100, 150 mg Zn/kg) plus a Zn-unsupplemented control diet. The feeding trial lasted 42 days. The AFM image of CS–Zn showed a rougher appearance and smaller size particles. The changes in spectrum peaks evidenced the successful chelating of Zn2+ with chitosan. The XRD patterns revealed the formation of a new crystalline phase. Moreover, the oral acute toxicity test of CS–Zn showed no lethal effects on mice. Weaned piglets fed dietary CS–Zn showed improved weight gain and decreased diarrhea incidence. Additionally, the bioavailability of CS–Zn was higher than that of ZnSO4 in piglets. Taken together, these results indicate that the prepared CS–Zn chelate, with rough surface and crystalline phase, is non-toxic and show enhanced bioavailability.