Gene transfer experiments in cattle.

Various methods for gene transfer in cattle are described. Four vectors containing (1) the bovine papilloma virus DNA, (2) the alcohol dehydrogenase gene of Drosophila melanogaster, and the human (3) and the bovine (4) growth hormone gene were used for gene injection in bovine zygotes. The period between 78 and 82 h after prostaglandin treatment was determined as the optimum time for collection of bovine zygotes.