Bacillus licheniformis as a protective agent in broiler chicken concurrently exposed to mycotoxins and necrotic enteritis: Toxicopathological and hematobiochemical perspectives.

Mycotoxins negatively impact intestinal cell viability, leading to the depletion of beneficial bacteria and rendering birds susceptible to intestinal infections such as necrotic enteritis (NE). Furthermore, they impair the effective digestion and absorption of nutrients. This study aimed to evaluate the effects of Bacillus licheniformis supplementation on broiler birds exposed to mycotoxins and subsequent necrotic enteritis infection. A total of 280 one-day-old broiler chicks were divided into eight groups and subjected to B. licheniformis supplementation (1 × 10 CFU/kg of feed) and mycotoxin exposure (aflatoxin and ochratoxin A, each at 150 ppb). Clostridium perfringens (3 × 10 CFU/ml) was later administered to induce necrotic enteritis. This study evaluated body weight, feed intake, relative organ weights, hematological and serum biochemical parameters and performed histopathological examinations of liver, kidney and intestine. All the obtained data was statistically analyzed (P ≤ 0.05). The results demonstrated that B. licheniformis supplementation reduced the susceptibility to necrotic enteritis in broilers initially exposed to mycotoxins. Body weight and feed intake were significantly decreased in groups challenged with mycotoxins and necrotic enteritis, both individually and concurrently, compared to the control group. Relative weights of the liver, kidney and intestine were significantly higher in treatment groups. Hematological analysis revealed significantly lower erythrogram parameters (TEC, Hb, and PCV) in birds fed mycotoxin-contaminated feed, with or without necrotic enteritis. Hepatic and renal biomarkers were significantly elevated, and serum protein levels (total protein, albumin) were significantly lower. In contrast, birds supplemented with B. licheniformis and challenged with either mycotoxins or NE showed no significant differences in body weight, feed intake, erythrogram and leucogram compared to the control group. However, B. licheniformis did not mitigate these effects when supplemented in group with concurrent challenge of mycotoxins and NE, however, intensity of changes was reduced. In conclusion, B. licheniformis supplementation effectively alleviates the pathological changes induced by mycotoxins and necrotic enteritis when presented individually but is not sufficiently effective against the combined challenge of mycotoxins and necrotic enteritis.