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

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

Submitted to: Frontiers in Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/13/2022
Publication Date: 7/22/2022
Citation: Shanmugasundaram, R., Adams, D., Ramirez, S., Murugesan, R., Applegate, T., Cunningham, S.B., Pokoo-Aikins, A., Glenn, A.E. 2022. Subclinical doses of combined fumonisins and deoxynivalenol predispose Clostridium perfringens-inoculated broilers to necrotic enteritis. Frontiers in Physiology. 13: 1-15. https://dx.doi.org/10.3389/fphys.2022.934660.
DOI: https://doi.org/10.3389/fphys.2022.934660

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 (NE). 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 induced with NE. A total of 480 day-old male broiler chicks were divided into four treatment groups; 1. Control group (Basal diet + Clostridium perfringens); 2. Necrotic enteritis 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). Birds in NE and FB+DON+NE groups received 2.5 X 103 E. maxima on d 14. All birds were inoculated with C. perfringens on d 19, d 20, and d 21. On d 14 (pre-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 control group. On d 35, birds in the NE, FB+DON, and FB+DON+NE groups had 242, 84, and 339g lower BWG and 19, 2, and 22 points increase in FCR than those in the control group. Subclinical dose of FB+DON increased (P < 0.05) the NE lesion scores compared to that in the control group on d 21. The presence of FB+DON in NE-induced birds further increased (P < 0.05) the NE 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 (P < 0.05) jejunal claudin-1, claudin-2, and zona occludens-1 mRNA transcription levels, and a 4-fold increase (P < 0.05) in cecal tonsil IL-1 mRNA level compared to that in the control group. On d 21, birds in the NE group had a 24% decrease (P < 0.05) in villi height to crypt depth ratio compared to the control group and the presence of FB+DON in NE-induced birds further decreased the villi height to crypt depth ratio by 8.4% scores compared to that in the NE group. On d 21, d 28, and d 35, birds in the NE, FB+DON, and FB+DON+NE groups had an approximately 1.3-fold increase (P < 0.05) in C. perfringens loads in the cecal tonsils compared to that in the control group. On d 21, birds in the FUM+DON group had a lower (P < 0.05) Lactobacillus load in the cecal content and a lower (P < 0.05) CD8+: CD4+ cell ratio in the cecal tonsils compared to those in the control group. It can be concluded that subclinical doses of combined FB and DON predisposes C. perfringens-inoculated birds to NE, and the presence of FB+DON in NE-induced birds exacerbated the severity of NE.