The lipid characterization of storage fat, subcutaneous fat and bone marrow, originated from three different bovine categories, calf, young bull and cow, was carried out in order to develop a re-use of these by-products. After the lipid extraction, the compositions in fatty acids, triacylglycerols and cholesterol were determined by GC-FID. A total of 25 fatty acids were identified in all by-products; the oleic acid was the preponderant component, followed by palmitic, stearic, palmitoleic, linoleic and myristic acid. The long chain triacylglycerols (T48, T50 and T52) were the main products, especially in the cow's by-products. The subcutaneous fat of all animals showed the highest cholesterol content, whereas it was present in low amount in the others. Phospholipids were analysed in bone marrow of all the animals and phosphatidylcholine was the most abundant compound. Because of the high fat content and essential fatty acids and the low cholesterol amount, storage fat and bone marrow could represent a valuable lipid resource in food and pharmaceutical industry.