Biostimin is a well-balanced formula of immunostimulators, bactericidal, virucidal and anti-inflammatory substances. The properties of the active agents (poliphenol acids, flavonoids, polyacetals, alkylamides) and the synergy of their activity allow safe application of biosimin in cases when there is a necessity to raise the immunity against infections or in course of recovery from diseases affecting the immunity. Due to the stimulation of the immune system and its anti-inflammatory properties, biostimin is suggested for use in vaccination periods and in course of most health problems of birds. It can be applied along with antibiotic or mineral-vitamin supplements.