Dietary supplementation of Allium hookeri improved intestinal immune response on necrotic enteritis of young broiler chickens

Abstract

Abstract This study was conducted to evaluate the effects of dietary Allium hookeri on intestinal immune response of young broiler chickens induced with necrotic enteritis (NE). One hundred fifty birds (1 day old) were randomly assigned to 6 groups (n =25 birds/treatment) and fed a basal diet (control) or basal diet supplemented with Allium hookeri (AH) root at 1 or 3% of the basal diet; AH1 and AH3, respectively. Birds were orally challenged with E. maxima 41A (1 × 104 cells/chicken) on day14 and followed by C. perfringens infection (1 × 109 CFU/chicken) on day18. NE-associated infection and intestinal immune response were assessed by average body weight gain, lesion score and oocyst shedding. The effect of dietary supplementation with AH on transcript levels of pro-inflammatory cytokines, tight junction and mucin protein in the jejunum were quantified by qRT-PCR. At day 20, the birds fed 3 % of AH in diet (AH3) significantly weighted more than the control group though the NE-challenge significantly reduced average body weight gain compared to the uninfected control group. Among the NE-challenged groups, gut lesion score and oocyst shedding significantly decreased in the birds given with AH (1 or 3%) compared to the control group. Gene expression levels of pro-inflammatory cytokines IL-8, IL-17α, and LITAF decreased in AH3 groups compared to the infected control group though the levels significantly increased in the NE infected groups. Interestingly AH significantly increased transcript levels of intestinal tight junction proteins and mucin at 1% of diet, not 3% of diet. These results suggest that dietary supplementation of AH can improve chicken health by controling immune response against NE and it depends on the dietary level of AH.