Multiple mycotoxin exposure affects immune response, amino acid digestibility, and intestinal morphology in broiler chickens

Authors: Shanmugasundaram, Revathi; KAPPARI, LAHARIKA - University Of Georgia; PILEWAR, MOHAMMAD - University Of Georgia; JONES, MATTHEW - Southern Poultry Research, Inc; OLUKOSI, OLUYINKA - University Of Georgia; Pokoo-Aikins, Anthony; APPLEGATE, TODD - University Of Georgia; Glenn, Anthony

Submitted to: Toxins
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/29/2024
Publication Date: 1/1/2025
Citation: Shanmugasundaram, R., Kappari, L., Pilewar, M., Jones, M., Olukosi, O., Pokoo-Aikins, A., Applegate, T.J., Glenn, A.E. 2025. Multiple mycotoxin exposure affects immune response, amino acid digestibility, and intestinal morphology in broiler chickens. Toxins. Toxins 2025, 17(1), 16. https://doi.org/10.3390/toxins17010016.
DOI: https://doi.org/10.3390/toxins17010016

Interpretive Summary: Mycotoxins are harmful substances produced by fungi that create significant problems for the poultry industry. Chickens are continuous feeders, and even subclinical doses of mycotoxins can damage their intestines over a period of time and cost the producers money. It is important to understand the mechanism and doses that are involved in the impaired immune response, and nutrient absorption is critical for developing strategies to mitigate the negative effects of mycotoxins and ultimately improve chicken production performance and health. Hence, this study aimed to identify the lowest mycotoxins combination that does not compromise immune function or production performance in broiler chickens. This study found out that when broiler chickens were exposed to mycotoxins concentrations well below the FDA-recommended guidelines, there was a significant reduction in body weight gain, disruptions in intestinal morphology, immune regulation, and intestinal health. Results indicate that mycotoxins =1 mg/kg diet did not negatively impact the chicken health, thus identifying an upper threshold to avoid. These findings suggest that poultry producers may benefit from periodic testing of the feed while also considering the combined effects of multiple mycotoxins rather than focusing solely on individual toxins.

Technical Abstract: Fusarium mycotoxins often co-occur in broiler feed, and their presence negatively impacts health even at subclinical concentrations, so there is a need to identify concentrations of these toxins that do not adversely affect bird health and performance. The study was conducted to identify the least toxic effects of combined mycotoxins fumonisins (FUM), deoxynivalenol (DON), and Zearalenone (ZEA) on the production performance, immune response, intestinal morphology, nutrient digestibility of broiler chickens. A total of 960 one-day-old broilers were distributed into eight dietary treatments: T1 (Control): basal diet containing 0.8 mg FUM + 0.4 mg DON/kg diet, T2: 33.0 mg FUM + 3.0 mg DON + 0.8 mg ZEA/kg diet, T3: 14.0 mg FUM + 3.5 mg DON + 0.7 mg ZEA/kg diet, T4: 26.0 mg FUM + 1.0 mg DON + 0.2 mg ZEA/kg diet, T5: 7.7 mg FUM + 0.4 mg DON + 0.1 mg ZEA/kg diet, T6: 3.6 mg FUM + 2.5 mg DON + 0.9 mg ZEA/kg diet, T7: 0.8 mg FUM + 1.0 mg DON + 0.3 mg ZEA/kg diet, T8: 1.0 mg FUM + 0.5 mg DON + 0.1 mg ZEA/kg diet, with different mycotoxin concentration from T2 (highest) to T8 (lowest). The results showed that exposure to higher concentrations, T2 and T3, had significantly reduced the BWG by 17% on day 35 (p<0.01). The T2, T3, and T4 groups had a significant decrease in villi length in the jejunum and ileum (p<0.01) and disruption of tight junction proteins occludin and claudin-4 (p<0.01). Higher mycotoxin groups T2 to T6 had a reduction in the digestibility of amino acids methionine (p=0.012), aspartate (p=0.022), and serine (p=0.022); reduction in CD4+and CD8+ T- cell populations (p<0.01) and increase in T regulatory cell percentages in the spleen (p<0.01); decrease splenic macrophage nitric oxide production and total IgA production (p<0.05); upregulated cytochrome P450 enzymes expression (p<0.01). Birds fed the lower mycotoxin concentration groups, T7 and T8, did not have a significant effect on performance, intestinal health, and immune responses, suggesting that these concentrations pose the least negative effects in broiler chickens.