Buffered formic acid and a monoglyceride blend improve performance and modulate gut bacteria and immunity gene expression in broilers under necrotic enteritis challenge

Abstract

<p>Due to the removal of antibiotics from animal feed, alternatives have been sought to control necrotic enteritis (<b>NE</b>) in broilers. The current study investigated the effects of buffered formic acid (Amasil NA) and monoglycerides of short- and medium-chain fatty acids (Balangut LS P) on the performance and gut health of broilers challenged with NE. A total of 816 as-hatched 1-d-old chicks (Cobb 500) were randomly assigned to 6 treatments with 8 replicates. Treatments were: T1) nonchallenged control; T2) NE challenged control; T3) Amasil NA (challenge plus Amasil NA, 0.3% throughout all phases); T4) Balangut LS P (challenge plus Balangut LS P, 0.5%, 0.3%, and 0.2% in the starter, grower and finisher phases, respectively; T5) Combined (challenge plus combination of T3 and T4); T6) Antibiotic (challenge plus Zn bacitracin, 0.05 % throughout all phases). Birds were orally gavaged with live <i>Eimeria vaccine</i> species (d 9) and with <i>Clostridium perfringens</i> (d 14 and 15). On d 16, birds were sampled to evaluate gut permeability, microbiota, and mRNA abundance in the jejunum. The data were analyzed in JMP software using one-way ANOVA with Tukey's test to separate means, and Kruskal-Wallis test was used for non-normally-distributed parameters. Results showed that Balangut LS P decreased (<i>P</i><0.05) feed conversion ratio compared to nonchallenged ones at the end of the study. Balangut LS P reduced (<i>P</i> < 0.05) the level of cecal Bacteriods compared to nonchallenged group, whereas Amasil NA shifted the levels of ileal <i>Bifidobacteria</i>, Enterobacteriaceae, and <i>Lactobacillus</i> towards nonchallenged control (<i>P</i> > 0.05). NE challenge upregulated (<i>P</i> < 0.001) the expression of IL-21R, zeta chain of T cell receptor (ZAP70), and dual specificity phosphatase 4 (DUSP4) compared to nonchallenged birds, whereas Balangut LS P showed an intermediate (<i>P</i> > 0.05) expression pattern of these genes towards nonchallenged and antibiotic groups. In conclusion, combination of Balangut LS P and Amasil NA has the potential to be used as an additive to improve the performance and gut health of broiler chickens, especially under challenging conditions such as NE infections.</p>