N. Grozeva, I. Valchev, D. Kanakov, Ts. Hristov, L. Lazarov, R. Binev, Y. Nikolov

Abstract. Ducklings are among the most sensitive avian species to the toxic effects of aflatoxin В (AFB ). In this experiment, the toxic effects of AFB on liver 1 1 1 morphology, blood plasma aspartate amino-transferase (AST), alanine amino-transferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), γ-glutamyltransferase (γ-GT), albumin, blood glucose, and plasma total protein (TP) were established in mulard ducks. The experiment was carried out with four groups of 20 10-day-old ducklings each. Each group included three subgroups with 10 birds. The groups were as followed: group І – control (which received standard feed according to the species and age), group ІІ – experimental, which received compound feed with 0.5 mg/kg AFB , group ІІI– receiving 1 compound feed supplemented with 0.8 mg/kg AFB and group IV – compound feed supplemented with 0.5 mg/kg AFB and 2g/kg Mycotox NG. The 1 1 experiment lasted for 42 days. Blood biochemical data on the 21st day of the experiment showed increased activity of assayed enzymes and reduced concentrations of albumin, total protein and glucose in groups receiving only AFB . The observed changes tended to become more pronounced by the 42nd 1 day of the trial. Macroscopically, livers were enlarged, rounded, with yellowish colour and a frail consistency. Histopathologically, a various extent of dystrophy was detected depending on the dose of ingested toxin. The addition of 2 g/kg Mycotox NG to the feed of experimental group IV (containing 0.5 mg/kg AFB ) 1 reduced the harmful effects of AFB on blood biochemical indices and significantly lowered the severity and frequency of observed histological lesions.