The aim of the study was to determine the influence of biomass and cultural liquid obtained as a result of increased strains Streptomyces on biochemical parameters in blood serum of chickens during starter and growth periods. All groups of the chicks were keep in analog conditions and were feed with standard balanced ration. For analysis the samples of blood was collected of decapitation chickens and from the jugular vein at the age 1, 25 and 53 days. The studied indicators of blood serum was which was: urea, uric acid, glucose and alkaline phosphatase. Estimated parameters, with the exception of alkaline phosphatase concen5tration were dependent of the chicken age. The higher levels of these metabolites were obtained at age of chickens 53 days. They were being increased on chickens from groups III. and IV (602.7 mcmol respectively 511 / l) and lower in groups I and II (483, 67 and 431.4 mcmol / l). The concentration of glucose at the age of 25 days compared with one day age chickens increased on average by 2,11mmol / l, recorded significant growth in groups I and III (0.6 and 1.5 mmol / l), and in group II had the highest 8.17 mmol / l. Comparison of alkaline phosphatase of chickens at 25 days age recorded values in gr. II, III and IV was higher compared with control groups and have conteines 975.67, 553 and 751.67. The results can be helpful in assessing changes in the metabolic profile and health chickens at starter and growth phases