EN
The studies were carried out in the farm SK Bielin, on 45 calves. The prevalence and intensity of the Coccidia infection were determined by means of the Willis-Schlaaf's and McMaster's methods. Whereas the Coccidia composition in the examined animals was determined by the morphological features of the oocysts and the sporulation time. The following six Eimeria species were isolated in the commercial fanns - E. bovis, E. aubernensis, E.zurni, E. ellipsolidalis, E. subspherica and E. cylindrica. The calves were divided into control and two experimental groups - 15 animals per group. Anticoc was administered for 5 days in a dose of 0,9 ml/10 kg of body weight. Baycox was administered twice in 7 days interval in a dose of 20 mg/kg of body weight. The weight gain and the course of coccidia infection in calves before and after treatment with Baycox and Anticoc were examined. In control group the coccidia infection was very high. After administration of Anticoc the intensity of coccidia infection was falling down and 0-180 oocysts were found in 1 g of feces. After administration of Baycox the intensity of coccidia infection was very low and only 0-80 oocysts were found in 1 g of feces. The results were analysed statistically, and significant differences between the treated and untreated animals at P≤0.01 were observed.