In a private farm the effects of mycotoxicosis and / or brucellosis were studied on buffaloes and caille. from each of species (one month after abortion or normal parturi ­ tion) twenty animals were divided into four equal groups. Theftrst group was served as control animals, the second group was non-infected animals but the mycotoxins were detected in their serum, the third group was naturally brucella infected animals and litefourth group was both naturall y brucella irifected and mycotoxin poisoned ani­ mals. Brucellosis was identified serologically and from the clinical signs. Mycotoxicolog­ ical. serological, hormonal. serum protein electrophoretical and biochemical studies were carried out. Results indicated that the mycotoxins which were detected in serwit of caille and buffaloes are ajlatoxin-B l ocltratoxin-A and fumonsin-B l by a concentra­ tions in buffaloes more than that in cattle. In contrast, the higher brucella titers were detected in cattle than that in buffaloes. Mycotoxicosis and/ or brucellosis could in­ duced reproductive disturbances (due to the changes of serum progesteron, estrogen, triiodothyronin (T3) and thy roxin (T4) hormones}, immunosuppression by mycotoxicosis in buffaloes (because of gamma globulinemia}, metabolic disturbances (due to the in­ crease of T3, T4 and total lipids), and liver dysunciion in buffaloes (due to the increase of total bilirubin concentration. and the activity of ALT enzyme). The mycotoxins sltoulcl be chicked in regions of high incidence of brucellosis in order to controlling or diminut­ ing the mycotoxicosis which is a predisposing stress factor for occurrence of infections by their immunodepressant properties.