The cow joins the rat, mouse, dog, chimp and humans as the latest animal to have its draft genetic code unveiled. Scientists hope that the achievement will help agricultural researchers improve the health of cattle, as well as the quality of beef and dairy products. The data, which has been deposited into free public databases, will also help genetics researchers learn more about the human genome. A detailed version of the cow genome will be available in 2005, say the researchers, who are based at institutes in the US, Canada, New Zealand and Australia.

The complete genetic code of the cow (Bos taurus) is made up of around three billion DNA 'letters' (base-pairs) - the same number as humans and other mammals. The $53 million effort to determine the order, or sequence, of these DNA base-pairs was lead by scientists at the US National Human Genome Research Institute. Since the final version of the human genome was published in April 2003, scientists have been studying the genomes of other animals, to help them understand the human genetic code. The complete cow genome could also help researchers fill in some of the last remaining gaps in the human sequence, according to study author Ross Tellman: 'There are still difficulties associated with the human sequence, difficult areas that still need a bit of work', he said.

The bovine genome sequenced in detail is that of a single Hereford cow, but the researchers also plan to do rough versions of other breeds, including the Holstein, Angus, Jersey, Limousin, Norwegian Red and Brahman. 'We should be able to select the best production traits of certain cattle and get rid of those traits or genes we don't want', said Tellman, adding 'those traits could be in terms of disease resistance or weight gain or in a host of other areas'.    

Tim Hubbard, of the UK's Wellcome Trust Sanger Institute, said that like dogs, the cow was a good animal model to study because of its long history of breeding by people. 'If you think about the variation in the height of the dog or the variation in milk yields in cows or other factors - the point is you can relate those things which have been bred against the genes underneath', he told BBC News Online.