The unravelling of the Hereford Cow’s genome and the publication of its gene sequence could lead to serious transformation in future farming practices, scientists say. After a six year discovery, the cow genome has now joined the likes of humans, primates and rodents with all 22,000 genes being fully mapped. Proving to be far similar to the human genome than that of rodents, scientists are expecting genetics to take a major role in future bovine livestock breeding. And mapping the genome could have further benefits too. With their genome closer to us than lab rats, many of which have products tested upon them intended for the human market, human biology may also be learnt from this newly discovered sequence.
Of the 22,000 genes, 14,000 are common to all mammals, the remaining 8,000 distinctly specialised to each species. By closely analysing the differences between varieties of stock, the functions of specific genes and gene groups can be clarified. Physical differences within cattle varieties can then be associated with certain genes and it is hoped that this process can lead to breeding better herds.Already in motion, a scientific team have begun to compare the genome of the Hereford cow to that of six other varieties. Using what they call a bovine “HapMap”, they can then track the variations within a cattle type to discover differences between breeds leading to differentiating milk and meat yields. Natural methods of livestock breeding may well continue, but with the genome knowledge, better stock pairings can be made, hopefully leading to healthier herds which produce more.And it certainly will lead to fast track improvement for dairy and meat livestock. Currently and for the most part, bulls are selected for breeding to create better cattle. It can take up to five years to determine a bull’s characteristics but with the genome knowledge and some genetic tests, essentially you can select your bulls at birth.
In addition to thoughts of produce increase, immunity genes have also been discovered. Being ruminants, that is having four-chambered stomachs, leads to a very high population of bacteria within each individual. Though evolution has built some resilience to this, cattle are still vulnerable to disease, with high herd density increasing problems further. It is hoped that in addition to changes to breeding lineage, scientists will also be able to tackle disease resistance. This genome knowledge could also lead to breeding stock which has lower carbon footprint, particularly in respect to the production of greenhouse gases by the dairy and meat industries.
Soon after the workshop on Climate Change and Water Stress in the Eastern Himalayan River Basins in Kathmandu, I left on a family holiday to Kenya. This was the African Safari we had been dreaming about…. seeing the Big Five, apart from giraffes, zebras, hippos…. Little did I think that climate change and water stress would continue to occupy my thoughts.Our first stop, Samburu National Reserve in Northern Kenya lies in a semi arid desert that extends all the way to Ethiopia. Unique to this region are a number of animals, which include the Grevy’s Zebra (delicately patterned), the reticulated giraffe, oryx, gerenuk (with its long neck reaching out to the higher branches, one can almost see natural selection in action) and the truly majestic Somali ostrich. The people of Northern Kenya, the Samburu, cousins to the better known Southern Maasai, are warrior nomads often seen tending their livestock and cattle along the dusty trails in the park.
The first couple of sojourns into the reserve left us gasping for breath at the profusion of animals that we saw. Then a Samburu naturalist, a.k.a. Daniel gave us a talk on the region. He spoke about climate change and how it is affecting the Samburu lands. In the last two years, the rains have failed them 5 times. There has not just been less rain; in the last session of long rains (April-May 2009) they had no rain at all. “I believe it’s due to something called global warming”, said Daniel, “we are seeing it happen before our eyes.” Daniel himself has seen his herd of cattle dwindle from 50 to 10 in the last few months. If the short rains in the end of October do not arrive, he expects all the livestock to die.For the Samburu people, their cattle is their wealth and the social system is based on exchange of cattle. The decline in cattle population affects the health of the communities, as malnutrition and disease sets in, as the Samburu, are highly dependent on the blood, milk and meat of their livestock for food. Parents cannot marry their children off if they do not have cattle. A boy cannot attain manhood if he does not have cattle. Attendance in schools is declining as families move further and further away in search of fodder and access to heath centers. There is also talk of rising tensions between the different communities over scarce resources.Some species of wild animals in the reserve are doing slightly better at present, as they are more adapted to the dry land conditions and occasional drought. In fact, at present the scavengers are doing particularly well with the high rate of death among domesticated livestock. However, it is expected that the zebras, the giraffes and the gerenuk that we saw will also start to perish if the next round of rains at the year end do not arrive in time.
Looking at the longer term is also not very encouraging. Climate change models have predicted that drought in the pastoral lands of Africa will double by the end of this century, and that while the number of drought periods may not significantly increase; they are likely to last for longer, making recovery more difficult.We went on to our next stop, Lake Nakuru National Park in the Rift Valley area to see a multitude of flamingoes. Later we did see the Big Five as well…. a truly exhilarating experience. But the images of the Samburu lands and its current plight remain deeply etched in my mind. Will the Samburu people be able to overcome the current crisis or will the song of the Samburu be silenced forever?