Skim Milk Cows...

Milk fat is one of the most consumed fats in Australia and as a result enjoys a significant market value of many billions of dollars per year.

However most of the recent dietary guidelines suggest avoiding saturated animal fats and replacing them with low fat products and unsaturated fatty acids fats. Some geneticists are therefore studying the possibility of improving the milk composition to match the expensing demand.

A natural genetic selection obviously occurs in dairy farm with the use of breeds such as Friesian or Jerseys, which produce large amount of milk with about 3 or 4 % of fat. Nevertheless with 98% of the milk fats being triglycerides, the scientists are more focused on reducing the amount of saturated fatty acids.

By cloning and sequencing the major genes coding for the fatty acid composition of milk, identifying the polymorphisms between the coding and regulatory regions of those genes in dairy cattle breeds and evaluating the associations between these genetic variants, the geneticists know at the moment, that changing the genes sequences will allow the production of modified milk.

However, only a few days ago, a New-Zealander scientist announced that he was breeding a herd from a Friesian cow in which the genetic modification that codes for the production of healthier milk with low fat content, normal protein level and high percentage of unsaturated fats, has naturally occurred.

These cows could open a new era of dairy cows that produce healthier, softer and more marketable milk without being genetically modified by humans. The dairy company plans to have the first fresh skim milk products on the shelves by 2011.

Primary References:

Leake, J, 2007, Low-fat milk out of cow, The Australian News [http://www.theaustralian.news.com.au/story/0,20867,21803209-30417,00.html]

Niemann, H, Kues, W & Carnwath J, W, 2005, Transgenic farm animals: present and future, Revue Scientifique et technique Office International des Epizooties [http://www.oie.int/eng/publicat/RT/2401/24-1%20pdfs/25-niemann285-298.pdf]

Medrano, J.F, 2000, Modification of the Composition of Milkfat in Dairy Cows, UC Davis University, California. [http://www.cdrf.org/content.asp?contentID=99]

Posted by Chloé Lafleur (41365038)