Alteration of milk composition using molecular genetics.

Advances in genetic technology have made it possible to consider making substantial changes either in the composition of milk or in the production of entirely new products in milk. The technological capabilities that have given rise to the introduction and expression of new genes in animals are discussed. Examples are given of transgenic animals that express foreign proteins in their milk. Advantages of the mammary synthesis of proteins are discussed and potential alterations of milk composition and scenarios for introduction of new proteins are considered. Technological capabilities that either currently exist or are being developed are discussed along with the requirements for making it feasible to utilize the technology on a broad scale in dairy cattle.