Protective effects of humic acid against ochratoxin A-induced hepatorenal toxicity in broiler chickens

Ochratoxin A (OTA) is a common mycotoxin that impairs growth performance and induces hepatorenal toxicity in poultry. This study evaluated the toxicopathological effects of OTA and the protective role of dietary humic acid in broiler chickens. A total of 140 day-old broilers were divided into seven groups: control, OTA (400 ppb), humic acid (1.5 and 3 g/kg), OTA combined with humic acid (1.5 and 3 g/kg), and OTA with a commercial toxin binder for five weeks. OTA exposure significantly reduced behavioral scores (44 vs. 56 in control; maximum possible score = 60), decreased feed intake, and lowered body weight from week two onward. Relative liver and kidney weights were significantly increased in OTA-treated birds (3.57 ± 0.12 and 1.31 ± 0.11) compared to controls (3.03 ± 0.15 and 0.89 ± 0.04). OTA also caused significant hematological alterations, characterized by reduced hemoglobin, hematocrit, and erythrocyte counts, with increased leukocyte counts (p ≤ 0.05). Serum biochemical analysis showed decreased total protein and albumin, while creatinine, blood urea nitrogen, ALT, and AST levels were significantly elevated. Dietary humic acid, particularly at 3 g/kg, significantly improved growth performance, normalized hematological and biochemical parameters, and reduced hepatorenal lesions. Histopathological findings confirmed that humic acid markedly attenuated OTA-induced hepatic and renal damage. These findings demonstrate that humic acid effectively mitigates OTA-induced toxicity and may serve as a practical dietary strategy to improve poultry health and productivity.