The aim of the project will be to increase the digestibility of feed nutrients in broiler chickens. For this purpose, the synergistic effect of short- and medium-chain fatty acid esters and phytoadditives will be used. The challenge in animal nutrition is to increase the availability of bioactive compounds contained in plants. An innovative element will be the use of biotechnological methods (fermentation) to increase the availability of active substances, leading to an increase in nutrient digestibility and gut health (integrity). The composition of the final product will be based on multilevel testing of both individual substances and their combinations, both in vitro and in vivo conditions. The efficacy of the complete additives will then be verified under the operating conditions.