N. Grozeva1*, I. Valchev2, Ts. Hristov2, L. Lazarov2, Y. Nikolov2

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

Abstract. Aflatoxins are toxic metabolites produced by moulds of Aspergillus genus (the most relevant producers are Aspergillus flavus and Aspergillus parasiticus). The primary aim of the current research is to follow out the toxic effects of aflatoxin В1 on the morphology of small intestine, which is important for digestion and absorption of feeds and at the same time, to investigate the possibility for prevention of toxic AFB1 effects by addition of the mycosorbent Mycotоx NG (Ceva Sante Animale, France) to the feed. The experiments were carried out with 50 Cobb broiler chickens, divided in 5 groups of 10 chickens (5 male : 5 female in the groups): Group I – control (receiving feed according to species and age); Group II – supplemented with 1 g/kg Mycotox NG; Group III – supplemented with 0.5 mg/kg aflatoxin B1; Group IV – supplemented with 0.8 mg/kg aflatoxin B1; Group V – supplemented with 0.5 mg/kg aflatoxin B1 and 1 g/kg Mycotox NG. The experiment’s duration was 42 days. After conventional histological technics the light microscopical analyze determined that the morphological changes in all small intestine (duodenum, jejunum, ileum) in birds treated at 0.5 mg/kg AFB1 consisted in vascular hyperaemia, single haemorrhagies, partial desquamation of villous epithelium, rarefaction of cells in intestinal lymphatic follicles and in some areas, cup cell hypertrophy and weak distrophy of Lieberkühn glands. Chickens treated with 0.8 mg/kg AFB1 showed more intense dystrophic changes – necrobiotic to necrotic changes of intestinal villi, atrophy of Lieberkühn glands, mononuclear cell infiltration of the propria and severe rarefaction of lymphatic follicular cells. The dietary supplementation of chickens with Mycotox NG resulted in fewer and less severe histological changes – no haemorrhagies but only vascular hyperaemia.