EN
The aim of the study was to estimate the effect of tylosin and prebiotics (β-glucans and mannanooligosaccharides) added to feed on the phagocitc activity of polimorfonuclear leukocytes (PMNL) in calves. The study was performed on 36 clinically healthy, Black and White Lowland calves, aged 6-8 weeks. The animals were randomly divided into three equal groups. Calves in group I were fed a feedingstuff supplemented with tylosin. Group II received prebiotics, and group III (control) was fed the same feedingstuff without additives. The following phagocytic parameters were determined in the peripheral blood of the calves: phagocytic index (IF), the percentages of phagocytic (%kf) and NBT-positive cells, and the spontaneous migration of neutrophils (MG). The results showed that both prebiotics and tylosin caused a significant increase in the phagocytic activity of PMNL in the experimental groups. This was expressed by the higher values of the examined phagocytic parameters compared with the controls.