[Methods of production and perspectives for use of transgenic domestic animals]

The technique of microinjection is so far the only successful method of gene transfer in farm animals. Fertilized oocytes are collected from superovulated donors by flushing the oviducts and the exogenous gene construct is injected into the male pronucleus of zygotes before transfer into the oviducts or uteri of synchronized recipients. The resulting pups have to be tested for integration and expression of the foreign gene. Potential applications of gene transfer in farm animals are the improvement of growth parameters, the increase of disease resistance, the enhancement of reproduction rates, the increase of wool production of sheep, the alteration of metabolic pathways, the production of human hemoglobin in the blood of transgenic animals, the generation of transgenic animals as organ donors and the proteins in the milk of transgenic animals. Many studies showed, that farm animals are able to direct the expression of partially large amounts of foreign proteins for biomedical purposes into their milk. Therefore transgenic livestock could be an attractive alternative for conventional production methods.