Abstract: Compositions and methods are disclosed containing lingual lipase or another pregastric esterase as a nutritional composition for use in neonatal mammals or mammals with fat maldigestion. The compositions may be used as a stand-alone feed, or an additive to milk, milk or replacers. The composition may also include micronutrients, macronutrients, and bioactive dietary components for neonate mammals or mammals of any age with fat maldigestion Mammals include ruminants, porcines, horses, camelids, dogs, cats, or humans. Lingual lipase or pregastric esterase as a nutritional supplement may substantially improve the digestion of fats in mammals unable to effectively digest fats. The lingual lipase or esterase is preferably from an animal source. The composition may contain butterfat, micellar casein, whey, non-denatured proteins, and a source of lactose. Methods of treating fat maldigestion with the compositions are also disclosed.