Due to the shortage of feed, in particular a permanent deficit increasing protein feed with sufficient content of essential amino acids for feeding purposes are widely used microbial synthesis. The aim of our research was conducted to study the influence of drugs on the basis of Streptomyces fradiae 19 to change the composition of blood of broiler chickens during their growth. For obtaining biomass and complex of exometabolites, the strain was grown on complex medium R, comprising as main sources of carbon and nitrogen - corn flour, starch and a number of mineral salts. According to results the quantity of total proteins and albumins increase essential by administration in drink water of cultural liquid in concentration 1 ml / l compare with control by 32.6% and 29.2% respectively. The cholesterol decrease significantly only in first two groups (control and with use of biomass), but in the third is practically unchanged (cultural liquid). Best results according to quantity of triglycerides were obtained by using of cultural liquid, too (increased by 2.6 times more). Compare with control and group where was administrated in feed ratio 0.1% of biomass, after adding of cultural liquid the quantity of monocytes is more by ~30%; but according to values of lymphocytes, they are preserved on the same level after use of biomass in feed and significantly decrease in groups of control and where is use cultural liquid. In values of leukocytes, for all three groups there are not significant changes. Obtained results show the perspective of the direction of using products of microbial nature.