Cows, transgenic

Van Berkel, P.H., Welling, M.M., Geerts, M. et al. (2002) Large scale production of recombinant human lactoferrin in the milk of transgenic cows. Nature Biotechnology, 20 (5), 484—487. 

Are you willing to drink milk from a cow whose milk production has been increased by injections of bovine growth hormone Does it matter to you that this bovine growth hormone was created by transgenic bacteria Why or why not ... 

GenPhami International. Inc created Lite first transgenic dairy cow. The cow was used to produce human milk proteins for infant formula. 

Four lines of transgenic cows that harbor the rhLF were developed (van Berkel et al., 2002). The milk of these animals had 0.4,0.8,2, and 3 g/liter of the rhLF in their milk. These levels of expression remained constant throughout the lactation period of 280 days. The milk volume, cell counts, and proximate composition were not altered by the genetic transformation. The recombinant protein was structurally and functionally comparable to natural hLF and had similar iron binding and release and antibacterial activities. The authors further postulate that with such expression levels and an assumed milk yield of 8000 liters of milk per cow annually, one cow can produce about 24-kg rhLF in a year. Thus, a herd of a few hundred animals could produce enormous quantities of this biological protein in a year. 

Lactose intolerance is a distinct entity from cow milk protein sensitivity and causes abdominal pain, diarrhea, nausea, flatulence, and/or bloating. While avoidance of milk and other dairy products will bring relief in children suffering from lactose intolerance, it may cause problems in optimal bone mineralization owing to lack of calcium in diet. Several lactose-free and lactose-reduced milks are now available in markets to cater to such infants. The scope of transgenic technology to reduce the lactose content in the milk of small animals has been reviewed elsewhere in this chapter (Section IV.A). The extension of this technique to include farm animals is targeted in the future. 

With successful advances in research, several other recombinant proteins of pharmaceutical interest have been developed from the milk of transgenic animals. In this context, some human proteins have already been expressed with success. Products such as insulin and growth hormone have also been obtained from the milk of transgenic cows, sheep, or goats (Margawati, 2003). 

Bliss, R.M. (2005). Transgenic cows resist mastitis-causing bacteria, www.ars.usda.gov/is/ pr/2005/050404.htm. 

Zuelke, K.A. (1998). Transgenic modification of cows milk for value-added processing. Reprod. Fertil. Dev. 10, 671-676. 

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