HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Wheeler, M. B. Search for Related Content PubMed PubMed Citation Articles by Wheeler, M. B.

Production of transgenic livestock: Promise fulfilled¹

Department of Animal Sciences, University of Illinois, Urbana 61801

² Correspondence: 366 Animal Sciences Laboratory, 1207 West Gregory Drive (217) 333-2239; fax: (217) 333-8286; e-mail: mbwheele{at}uiuc.edu

The introduction of specific genes into the genome of farm animals and its stable incorporation into the germ line has been a major technological advance in agriculture. Transgenic technology provides a method to rapidly introduce "new" genes into cattle, swine, sheep, and goats without crossbreeding. It is a more extreme methodology, but in essence, not really different from crossbreeding or genetic selection in its result. Methods to produce transgenic animals have been available for more than 20 yr, yet recently lines of transgenic livestock have been developed that have the potential to improve animal agriculture and benefit producers and/or consumers. There are a number of methods that can be used to produce transgenic animals. However, the primary method to date has been the microinjection of genes into the pronuclei of zygotes. This method is one of an array of rapidly developing transgenic methodologies. Another method that has enjoyed recent success is that of nuclear transfer or "cloning." The use of this technique to produce transgenic livestock will profoundly affect the use of transgenic technology in livestock production. Cell-based, nuclear transfer or cloning strategies have several distinct advantages for use in the production of transgenic livestock that cannot be attained using pronuclear injection of DNA. Practical applications of transgenesis in livestock production include enhanced prolificacy and reproductive performance, increased feed utilization and growth rate, improved carcass composition, improved milk production and/or composition, and increased disease resistance. One practical application of transgenics in swine production is to improve milk production and/or composition. To address the problem of low milk production, transgenic swine over-expressing the milk protein bovine -lactalbumin were developed and characterized. The outcomes assessed were milk composition, milk yield, and piglet growth. Our results indicate that transgenic overexpression of milk proteins may provide a means to improve swine lactation performance.

Key Words: -Lactalbumin • Mammary Glands • Milk • Transgenic Animals