The food conversion rate refers to the ability and efficiency of an animal to convert food into usable energy for growth and development. Synonyms for food conversion rate include feed efficiency, feed conversion ratio, and feed to gain ratio. These terms refer to the amount of feed or food input required by an animal to produce a unit of output, such as weight gain or milk production. Other related terms include nutrient utilization efficiency, energy balance, and metabolic rate. By understanding and optimizing food conversion rates, farmers and animal producers can improve their operations' sustainability, profitability, and environmental impact.