A genetically modified organism (GMO) means that a change has been made to the genetics of an organism by direct insertion of DNA pertaining to a specific trait. In nature this occurs as a mutation, where a spontaneous change in DNA results in a new trait. Selection for specific traits in plants and animals has been practiced by mankind for thousands of years. Commercially grown GMO crops used for animal feed in the US are currently limited to corn, soybeans, canola, alfalfa, cotton and sugar beets. GMO crops are not approved for use in certified USDA Organic products.