Effect of tetramethylpyrazine on growth performance, Campylobacter jejuni carriage and endogenous antimicrobial peptides in rabbits

Abstract

The present study aimed to investigate the effect of tetramethylpyrazine (TMP) supplementation on growth performance, Campylobacter jejuni (C. jejuni) carriage and antimicrobial peptides in the epithelial tissue of caecum and skin in rabbits. Five treatments included control and C. jejuni challenge with the addition of TMP at 0, 50, 100 or 150 mg/kg of diet. The trial lasted for 35 days and C. jejuni challenge occurred on first day of feeding trial. The results showed that C. jejuni challenge worsened (P < 0.05) feed intake, body weight gain and feed efficiency, whereas TMP supplementation partially compensated (P < 0.05) growth performance. C. jejuni populations in the caecal content and on the skin were decreased (P < 0.05) in the treatments containing TMP. The mRNA levels of antimicrobial peptides, including defensin neutrophil peptide 4, macrophage cationic peptide 2, galectin 3 and cathelicidin were also decreased (P < 0.05) by C. jejuni challenge while they were increased (P < 0.05) with supplemental TMP. Linear and quadratic trends (P ≤ 0.012) of the three doses of TMP were found in growth performance, linear trends (P ≤ 0.049) in C. jejuni carriage, and linear and quadratic trends (P ≤ 0.012) in galectin 3. The results suggest that TMP can partially protect from C. jejuni infection by decreasing C. jejuni carriage and activating epithelial antimicrobial peptides.