Oil in fat-filled milk powders is the major source of energy in calf milk replacers. Choice of oil source is determined by nutritive value (chiefly digestibility), functionality (avoidance of breaking the emulsion) and, increasingly, customer preference for oils of purely vegetable origin. One alternative to the use of traditional oil sources such as lard and fish oil, is coconut oil, which is rich in highly digestible medium-chain length fatty acids (particularly C12:0), but relatively deficient in essential long-chain polyunsaturated fatty acids such as linolenic acid. The objective of this experiment was to compare the effects on calf performance of oil source within milk replacers.