Effect of subchronic oral exposure to zearalenone on haematologic and biochemical analytes, and blood redox status of adult rabbit bucks

Background: Zearalenone (ZEN) is a mycoestrogen with ubiquitous presence in animal feeds, which has also hematotoxic, hepatotoxic, nephrotoxic and immunotoxic properties. However, a paucity of literature discusses its effect on rabbits. Objectives: The aim of this study was to evaluate the effect of a prolonged, low level (50μg ZEN/kg body weight) exposure on clinicopathological and redox status analytes of rabbit bucks. Methods: Ten adult bucks were included in the study, each of which underwent a 7-week control period, followed by a 7-week treatment period. Water or ZEN solution were daily administered orally (0.5 ml) during the control and treatment period, respectively. Blood samples were collected weekly and were assayed for CBC, serum biochemical analytes and reactive oxygen metabolites (ROMs). Data were analyzed using a mixed model and a level of significance <0.05 was assumed. Results: During the ZEN treatment period, significant increases were noted in RDW and MPV values, as well as in WBC, monocyte and eosinophil counts. Significant increases were observed in AST and total bilirubin values, whereas the concentrations of urea, creatinine, glucose, total calcium, sodium and potassium were significantly decreased. The concentrations of ROMs did not differ significantly between the control and ZEN treatment period. Conclusions: Under the present experimental conditions, ZEN affected some clinicopathological analytes of adult rabbit bucks, most consistent with mild hepatocellular damage and dysfunction, inflammatory and/or allergic response and renal tubular damage. Zearalenone dosed at 50μg ZEN/kg BW did not seem to affect blood redox status of bucks, as evaluated by ROMs concentration.