The future of transgenic farm animals

Animal scientists have dreamed of applying transgenic technology to improve production characteristics of farm animals for nearly two decades. Except for the special case of producing pharmaceutical products in milk, efforts have been disappointing. In retrospect, this is not surprising in view of our limited knowledge of gene regulation and function, particularly interactions and pleiotropic effects. Furthermore, insertion of constructs at random sites has much in common with random germline mutations that occur naturally; most such mutations have negative, if any, consequences for the organism (Crow, 1997). There also are serious nonmolecular limitations to generating transgenic farm animals, including high costs of animals and their care, lack of inbred lines, long generation intervals, small litter size in some species, expense of adequate replication and failure to develop usable embryonic stem cells. Over the next few years, transgenic techniques are more likely to be successful for obtaining basic information about farm-animal biology than for improving production characteristics such as growth or lactation rates. Ultimately the resulting information will lead to improved production traits, but the application phase often will not require transgenic procedures. Transgenic technology with farm animals is rapidly becoming more reliable and flexible at the same time as our knowledge of genes is increasing, in great part due to information from other species. This combination will lead to remarkably insightful findings over the next decade, and probably will result in several applications to production-animal agriculture. Finally, we must continue to share information and procedures, even when developed in the private sector, or with private-sector funding (usually with considerable public-sector input). Few organizations can afford to waste valuable resources on protracted litigation over intellectual property or circumventing inventions derived from obvious procedures that are either inappropriately patented, or appropriately patented but unavailable for licensing.