PROSPECTS FOR THE GENETIC MANIPULATION OF DAIRY-CATTLE - OPPORTUNITIES BEYOND BST

The dairy industry, with regulatory approvals of recombinant chymosin and bovine somatotropin (BST), has been at the forefront of food and a gricultural biotechnology. The commercial fate of these products is on e of several factors that may affect the success of future genetic man ipulations in dairy cattle and dairy products. Other factors include t echnical and reproductive constraints in cattle and the cost of produc ing transgenic cattle. Early applications of genetic manipulation in c attle, for reasons of cost recoupment, may favor production of heterol ogous proteins in mi Ik for pharmaceutical and medical use. Such appli cations could benefit genetic modification of milk and milk proteins f or food use by providing advance knowledge and experience in mammalian protein expression. Other research opportunity areas that could affec t prospects for genetic manipulation of dairy cattle include genome ma pping, metabolic pathways, growth and development, and cattle/microbe interactions.