In the conditions of the Republic of Belarus there was determined the influence of multi-enzymatic veterinary drug preparations Vitazim (contained a complex of enzymes of carbohydrases: xilanase; cellulose; beta-glucanase) and Ehkosim (universal multi-enzymatic complex: beta-glucanase; endo-xilase; and cellulase) on microbial composition of intestinal bacterial population. Research was realized by an example of layer hens of four-linear cross Highsex white at the age of 34-51 weeks. Regimens of administration of the analyzed preparations were presented. Research results showed promoted the development of the regenerative process of physiological media in intestines of poultry which was necessary for subsisting of normal flora of pathogenic bacteria. The studied preparations Vitazim and Ehkosim can be applied for the preventive treatment and therapy of intestinal dysbacteriosis, normalization of its microbial flora, as well as for the antibacterial therapy.

Studying of efficiency of application of a natural biological control agent BioLAD obtained as a result of cultivation of Fusarium sambucinum fungus in feeding of broiler chickens was realized in the conditions of the Republic of Belarus. There were studied 100 broiler chickens of Ross-308 cross. Broiler chickens of the first (control) group were fed with standard diet with PK-5-1. Broiler chickens of the experimental groups starting from one day old age till the end of the growing period (41 days old) were fed with feed supplement BioLAD in different doses: 0,25 ml/head (second group), 0,5 ml/head (third group), 1 ml/head (fourth group). Research results showed that natural biological control agent BioLAD in dose of 0,5 ml/head made it possible to increase chicken live weight on 11,2 %, viability - on 4,2%. Feeding charges per 1 kg of live weight gain were1,89 kg (second group), 1,81 kg (third group), 1,90 kg (fourth group). It made it possible to decrease the combined feed charges on 6,4% (second group), on 10,4% (third group), and on 5,9% (fourth group). Application of biological control agent BioLAD had an effect on poultry growth activity, promoted high level of chickens viability, increased the indices of general and local protection, stimulated metabolic processes