Riboflavin is required as part of many enzymes involved with metabolism of carbohydrate, fat and protein. Riboflavin in these coenzyme forms (FMN and FAD) are called flavoproteins and act as intermediaries in the transfer of electrons in biological oxidation-reduction reactions. If levels of riboflavin are low, the respiration process becomes less efficient, and 10% to 15% more feed is required to meet energy needs.
Riboflavin is synthesized by green plants, yeasts, fungi and some bacteria. Rapidly growing green leafy vegetables and forages, particularly alfalfa, are good sources, and the leaves have the highest content of the vitamin. Cereals and their by-products have a rather low riboflavin content, in contrast to their high thiamin content. Oilseed meals are fair sources, whereas grains should not be relied on as the sole sources of riboflavin.
Riboflavin is one of the more stable vitamins, but can be readily destroyed by ultraviolet (UV) rays or sunlight.
