In Europe, most cattle are bred as either dairy or beef cows, specialised for milk and dairy products, or for meat production, respectively, although some breeds are still farmed for both milk and meat, as they used to be in past generations. Today most European dairy cattle are black-and-white Holstein-Friesians. With beef cattle, however, there are many different breeds in use, as varied as black Aberdeen Angus, long-horned, hairy Highland cattle, or heavily muscled Charolais, for example. There are also local ‘minority’ breeds, often well adapted to their particular environment and location. Cattle are farmed in many different ways such as large, mostly indoor dairy units, medium sized family farms, and small-holdings. Cattle live naturally off grass but to improve production they are often given additional feed like sileage or grain.
Humans have been selecting animals for their own purposes since ancient times. Since the 18th Century people have bred livestock based on desirable characteristics, like physical appearance or easily judged factors like numbers of offspring or milk yield. But since the 1960s, in cattle scientists given 'scores' for animals against a wide range of heritable traits: not only growth rate or fertility, but things like disease resistance, feed efficiency, temperament and so on. These are taken not just from a cow or bull's animal’s parents, but siblings, cousins, etc. Advanced statistics and computing are used to turn these genetic data into 'breeding values', so farmers can choose which mix of traits calves from a given bull are likely to have.
Advances in Cattle Genomics
With the advances in genetic knowledge, DNA samples can be taken from cows which can be analysed to identify patterns in the genomes of cattle that are associated with inheritable traits. This can be done without knowing how all the individual genes work; and it is known as genomics.
In a European Commission research project called BovReg, geneticists are looking in greater depth into the way combinations of genes work together to produce different physical characteristics (phenotypes) Potentially this information will enable selection for a wider range of traits, including robustness to challenges they experience through their environment such as heat stress or disease, perhaps reducing methane emissions, and the value of local and minority breeds. The focus is on selecting cattle for breeding. This does not involve genetic modification by adding genes in the laboratory. Indeed 'GM' has not been used commerically for livestock production so far. In the future, some of the results from the BovReg project might suggest improvements that can be done in future by new methods like genome editing, but that would be a long way off. For the moment the focus is how to select for the cattle we want in future.
What do you think?
But what cattle do we want? In the BovReg project we are not only interested in what the experts aim to do, but we also want to know what you, in the wider public, think. What characteristics do you think farmers and breeders should be aiming to promote in their herds, with these new possibilities opening up using the science ofgenomics?
That is the purpose of playing this Democs card game. It has been written for the BovReg by Dr Donald Bruce, Managing Director of Edinethics Ltd., a consultancy company on ethics and technology, and Dr Ann Bruce, senior lecturer in Science Technology and Innovation Studies at the University of Edinburgh, who are both partners in the BovReg project. We invite you to play the game, read and discuss the cards with one another, and let us know what you think.