Subclinical doses of combined fumonisins and deoxynivalenol predispose Clostridium perfringens-inoculated broilers to necrotic enteritis

Authors: Shanmugasundaram, Revathi; ADAMS, DANIEL - University Of Georgia; Olson, Drew; RAMIREZ, SHELBY - Dsm; MURUGESAN, RAJ - Dsm; Mitchell, Trevor; APPLEGATE, TODD - University Of Georgia; Pokoo-Aikins, Anthony; Glenn, Anthony - Tony; Cunningham, Shawn

Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/21/2022
Publication Date: N/A
Citation: N/A

Interpretive Summary: The findings reported here have significant practical importance and reflect the real-world problem because of the common occurrence of Fusarium mycotoxins in poultry feeds and subclinical necrotic enteritis occurrence in the field. According to FDA, the recommended level for FB and DON in the poultry finished diet is 50mg/kg and 5 mg/kg. The level of FB and DON in the experimental diets of the current study is 3 mg/Kg FB +4 mg/Kg DON which is lot less than the recommended level and the findings represent chronic feeding of the subclinical level of FB and DON contaminated diets in broiler chickens and their role to induce subclinical necrotic enteritis. Our findings help to understand the mechanism behind the synergistic effect of combined toxins and predict the specific thresholds of combined toxin and their adverse effects in chickens. Our data suggests that chronic exposure to Fusarium mycotoxins not only directly affected the production performance but also influence chicken health by inducing necrotic enteritis and also increasing the severity of necrotic enteritis.

Technical Abstract: Fumonisins (FB) and deoxynivalenol (DON) are mycotoxins that frequently contaminate feedstuffs and cause damage to gut integrity, which may predispose broiler chickens to necrotic enteritis. The objective of this study is to identify the effects of subclinical doses of combined FB and DON on gut permeability, necrotic enteritis severity, immune parameters, and overall performance of birds challenged with Eimeria maxima at 14 d of age and subsequently Clostridium perfringens on d 19, 20, and 21. A total of 480-day-old male broiler chicks were divided into four treatment groups; 1. Control group (Basal diet + C. perfringens challenge); 2. Necrotic enteritis (NE) group (Basal diet + E. maxima + C. perfringens); 3. FB+DON group (Basal diet + 3 mg/Kg FB +4 mg/Kg DON + C. perfringens); and 4. FB+DON+NE group (Basal diet + 3 mg/Kg FB + 4 mg/Kg DON + E. maxima + C. perfringens). On d 14 (before challenge), birds in the FB+DON treatment had lower (P < 0.05) body weight gain (BWG) and 21 points (P = 0.05) increase in feed conversion ratio (FCR) compared to the unchallenged control group. On d 35, birds in the NE, FB+DON, and FB+DON+NE groups had 242, 84, and 339 g lower BWG and 19, 2, and 22 points increase in FCR than those in the control C. perfringens challenged group. Subclinical dose of FB+DON increased (P < 0.05) the Wilcoxon/Kruskal-Wallis Rank Score Means for lesion scores compared to that in the control C. perfringens challenged group on d 21. The presence of FB+DON in NE-challenged birds increased (P < 0.05) the Wilcoxon/Kruskal-Wallis Rank Score Means for lesion scores compared to that in the NE group. On d 21, birds in the NE, FB+DON, and FB+DON+NE groups had a 150, 51, and 293% increase (P < 0.05) in the serum FITC-D, respectively, and lower jejunal claudin-1, claudin-2, and zona occludens-1 mRNA transcription levels, and 4-fold increase in cecal tonsil IL-1 mRNA level compared to that in the control C. perfringens group. On d 21, 28, and 35, birds in the NE, FB+DON, and FB+DON+NE groups had an approximately 1.3-fold increase in C. perfringens loads in the cecal tonsils compared to that in the control C. perfringens challenged group. On d 21, birds in the FUM+DON group had a lower Lactobacillus load in the cecal content and a lower CD8+: CD4+ ratio in the cecal tonsils compared to those in the control C. perfringens challenged group. It can be concluded that subclinical doses of the combined FB and DON predisposes C. perfringens-inoculated birds to necrotic enteritis, and the presence of FB+DON in NE-challenged birds exacerbated the severity of NE.