The growing human population is associated with an increased demand for food including poultry industry products. In this industry, the majority of costs affecting the final price arise from feed expenses. Therefore, efficient feed utilization in poultry farming is important to reduce costs and protect the environment. Residual feed intake (RFI) is a metric used to assess which birds consume less feed than expected based on their needs while maintaining optimal production and health indicators. Scientists and breeders aim to gain a deeper understanding of the physiological and genomic basis of birds in terms of efficient feed utilization, namely what mechanisms determine the efficiency of nutrient digestion and absorption. Since this trait is partially heritable, it can be enhanced through the careful selection of breeding animals. However, both selection processes and the calculation of RFI must be conducted with precision, taking into account the production rates of birds due to the possible negative impact on them. Improved feed utilization leads to reduced resource consumption, lower costs and more environmentally sustainable poultry farming, which is beneficial for both producers and consumers.