Effect of

Essential oils as a feed additive in animal and poultry nutrition should preserve the bactericidal properties of blood and suppress the formation of bacterial biofilms. The study of bacterial biofilms and bacterial activity of blood serum in broiler chickens against the background of the addition of essential oil of Satureja montana to a diet was discussed in the article. Blood serum of broilers that received essential oil with feed suppressed the growth of the bacterial biofilms at S. aureus test culture by 60-72%. It serum had a weaker effect on the bacterial biofilms at E. coli test culture; it reduced the density by 23.5%. This effect began only after the 10th day of inclusions of essential oil. The blood serum of chickens that received essential oil in the form of aqueous solutions had a weak antimicrobial effect against growing the bacterial biofilms at S. aureus test culture; the density was 10% lower than that of the control. The growth of the bacterial biofilms of E. coli test culture was not inhibited