ABSTRACT
Approximately 12 million metric tons of rendered terrestrial animal fats are manufactured every year around the world. These lipids are generally more economical than fish and plant oils and find a wide use in animal feeds or industrial applications. Animal fats represent a very diverse group of products that are classified according to their origins and physicochemical characteristics. They are generally rich in saturated fatty acids, although some can be rich in monounsaturated fatty acids and polyunsaturated fatty acids. Early studies suggested that terrestrial animal fats were poorly digested and utilized by fish. However, numerous recent studies have shown that these lipid sources are well digested and utilized by most fish species. Terrestrial animal fats generally cannot be used as the sole lipid source in the diet of most fish species. Diets must be formulated to contain sufficient amounts of monounsaturated and polyunsaturated fatty acids to facilitate the digestion of saturated fatty acids and meet the essential fatty acid requirements of the animal. Terrestrial animal fats are increasingly recognized as safe and cost-effective lipid sources when used properly in fish feeds.
