EN
The response of broiler chickens on supplemented diets with Avilamycin (10 mg kg-1) or mannanoligosaccharides 1.0 or 2.0 / 1.0 / 0.5 g kg-1 analysed on basic of performance, carcass quality, number of microorganisms in jejunum and caecum content, was determined. The performance results by antibiotic and mannanoligosaccharides (MOS) supplementation of diets were comparable. Reduced number of intestinal pathogenic microflora (E. coli, Clostridium perfringens) was visible (p<0.05) in chickens from MOS (2.0 / 1.0 / 0.5 g kg-1) group in comparisons to control animals. The highest number of Lactobacillus spp. in intestine content was observed in antibiotic group.