Effects of dietary supplementation with the antimicrobial peptide WK3 on growth performance and intestinal health in diarrheic weanling piglets

This study aimed to determine the effects of the antimicrobial peptide WK3, as an alternative to antibiotics, on diarrheic piglets. Before treatment, all pigs were orally challenged with 10(8) CFU/ml enterotoxigenic Escherichia coli (ETEC) K88 for 3 days. Piglets were randomly divided into 3 treatments of eight piglets each, namely, the control treatment, antibiotic treatment and antimicrobial peptide treatment. The experimental results show that the addition of the antibacterial peptide WK3 to the diet can significantly reduce the chance of diarrhea. Compared with the CON group, average daily gain (ADG) and average daily feed intake (ADFI) of the WK3 group (P < 0.05) increased. Compared with that with the control treatment and antibiotic treatment, the level of GSH-Px in the jejunum significantly increased (P < 0.05) with WK3 supplementation. The numbers of bacteria, Lactobacillus spp. (P < 0.01) and Bifidobacteria spp. (P < 0.01), were higher in the WK3 group, but Enterobacterium spp. in digesta of the cecum were depleted (P < 0.01). The WK3 group decreased the expression levels of the inflammatory factors IL-1 alpha (P < 0.05) and TLR-4 (P < 0.01) in the jejunal mucosa contrast to the control treatment.