Opportunities for varying the composition of cows' milk*

At present, only two approaches for modifying the composition of bovine milk can be applied in practice: (a) changing to a breed other than the predominant Friesian and (b) dietary manipulation. Although other breeds may produce milk of high fat and protein content, the high yield of the Friesian, allied to the fact that it is an acceptable meat animal, probably ensures its continued dominance. In terms of diet, the content, yield and type of milk fat are easily susceptible to manipulation. However, the specialized diets required for this type of manipulation would probably incur extra costs, and it is not clear if the improved properties of the butter, eg, a butter having better low‐temperature spreadability, could attract a better return in the market. Protein content and yield are fairly insensitive to diet, and the consensus is that protein composition is invariant. Currently, the most sensible strategy for the dairy farmer appears to be to produce milk as cheaply as possible, and to leave it to the technologists to convert the components into a range of attractive, nutritious foodstuffs.