N. Groseva1, I. Valchev2*, Ts. Hristov2, L. Lazarov2, D. Kanakov2, R. Binev2

1Department of General and Clinical Pathology, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Internal Non-Infectious Diseases, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 21 August 2018; accepted for publication 28 January 2019)

Abstact. The aim of the present experiment was to investigate the toxic effects of aflatoxin В1 (AFB1) on immunocompetent organs (thymus, spleen, bursa of Fabricius) morphology. Also, the possibility for prevention of toxic effects of AFB1 by feed supplementation of a mycosorbent (Mycotox NB) was studied. The experiments were conducted with 4 groups of 20 10-day-old mulard ducks: group I – control, fed a standard compound feed according to the species and the age; group II – experimental, whose feed was supplemented with 0.5 mg/kg. AFB1, group III – experimental, supplemented with 0.8 mg/kg AFB1 and group IV – experimental, supplemented with 0.5 mg/kg AFB1 and 2 g/kg Mycotox NG. The duration of the experiments was 42 days. Atrophy and degenerative changes were observed in immunocompetent organs of birds from groups ІІ and III. The supplementation of the feed with 2 g/kg Mycotox NG resulted in partial neutralisation of deleterious effects of AFB1 on severity of histological lesions (considerably slighter lymphoid follicle rarefaction).