Effects of Zinc Oxide/Zeolite on Intestinal Morphology, Intestinal Microflora, and Diarrhea Rates in Weaned Piglets

This experiment was conducted to investigate the effects of zinc oxide/zeolite on growth performance, serum biochemistry, intestinal morphology, and microflora of weaned piglets. Two hundred and fifty-six weaned piglets (Duroc × Landrace × Large) at 21 days of age were randomly assigned to 2 groups with 8 replicates and 16 piglets in each pen. The diets of high dose of zinc oxide group (HD-ZnO) supplemented with 1500 mg/kg zinc as zinc oxide, but the diet of experimental group supplemented with 500 mg/kg zinc as zinc oxide that supported on zeolite (SR-ZnO). The experiment was conducted for 2 weeks after weanling. The results showed replacement of high-dosed zinc oxide by SR-ZnO had no significant effects on growth performance and intestinal morphology. However, the dietary supplementation of SR-ZnO reduced the diarrhea rate (P < 0.05), increased the activity of serum alkaline phosphatase (ALP) (P < 0.01), and tended to reduce zinc release in stomach (P = 0.06) and increase serum total protein (TP) (P = 0.07). Although there were no significant effects in ileal microflora on α diversity, the abundance of Campylobacters was found significantly decreased (P < 0.05), whereas the abundance of Clostridium was increased (P < 0.05) after lower-dosed SR-ZnO replacement. It is revealed that replacement of HD-ZnO (1500 mg/kg) by SR-ZnO (500 mg/kg) in creep feed could improve the zinc bioavailability, regulate the intestinal flora, and alleviate the postweaning diarrhea in weaned piglets. Accordingly, the application of SR-ZnO would reduce the zinc in feed and therefore benefits for the ecological environment.