Abstract
The aim of this experiment was to investigate the effects of benzoic acid and chelates in which copper (Cu), zinc (Zn) and manganese (Mn) were bound to methionine hydroxy analogue on growth performance, intestinal morphology, intestinal microbiota and digesta pH value of post-weaning piglets at 28 days of age. The experiment was conducted on 96 piglets randomly assigned to one of four treatments (6 replicate pens of 4 piglets each): 1) control (C) – microminerals were provided as sulfates of Cu, Zn and Mn at 130 (80 at second phase), 100, 120 mg/kg in the first phase, respectively; 2) chelates (CTM), microelements were provided as chelates of Cu, Zn and Mn at 130 (80 in second phase), 60, 60 mg/kg in the first phase, respectively; 3) benzoic acid (BA), with the addition of 2500 mg/kg during both periods; 4) chelates + benzoic acid (CTM + BA), microelements were provided as chelates of Cu, Zn and Mn at 130 (80 in second phase), 60, 60 mg/kg in the first phase, respectively, and 2500 mg/kg of benzoic acid during both periods. Results showed that chelates and benzoic acid supplementation not only improved the final body weight (p<0.05), average daily gain (p<0.05) and feed conversion ratio (p<0.05), but also increased the morphology performance and decreased the number of E. coli in the jejunum and ileum in the treated groups (p<0.05). This study provides the evidence that dietary supplementation has beneficial effects on the intestinal morphology and microflora of weaned pigs, which can partly explain why growth performance of the piglets was improved.