Simple SummaryThe addition of various bioactive compounds to chicken feed has a positive effect on the health, production traits and general welfare of the animals. To use these compounds more efficiently, it is necessary to better understand the molecular relationship between the nutrients in the feed and the genes that trigger the change to a preferred phenotype. This can be achieved with the help of nutrigenomics, a science that studies the interaction between nutrients and the genome and their influence on metabolic and physiological processes in the body. By implementing the knowledge gained from nutrigenomics, it is possible to more efficiently produce high-quality chicken products that have a positive impact on human health.AbstractConsumer demand for high quality and safe foods that will have a positive impact on their health has increased in recent years. Today, it is possible to meet those demands by combining the genetic potential of domestic animals and applying different feeding strategies. Nutrigenomics is one of the “omics” sciences that studies the interaction between nutrients and the genome together with their influence on metabolic and physiological processes in the body. While nutrition of domestic animals is solely based on studying the influence of nutrients on animal health and production traits, nutrigenomics integrates the fields of nutrition, genomics, molecular genetics and bioinformatics. By understanding the molecular relationships between different forms and/or concentrations of nutrients in feed and genes, it is possible to answer the question of how small changes in the diet of farm animals can produce a quality product with positive effects on human health. The aim of this article is to describe how the manipulation of adding different nutrients in the feed affects the expression of different genes in chicken and consequently alters their phenotype.