Cloning the new frontier
OW Contributor | 4/23/2008, 5 p.m.
It's four o'clock in the morning, the milking machines at a dairy farm in Somewhere, USA are being attached to the utters of 700 cows to begin the day's liquid harvest.. Most of the 700 cows are the offspring of natural birth, but many are the result of unnatural births by means of cloning. The milk travels down stainless steel pipes eventually empting into large refrigerated bulk tanks mixing both the cloned and uncloned milk.
This scenario is very possible according to Dr. Allison L. Von Eenennaan; Animal Genomics and Biotechnology Extension Specialist, (Department of Animal Science, UC Davis). Von Eenennaan states that it would be extremely difficult to safely keep the five gallons that come from Bessie the clone separated from the 55 gallons that come from Elise and the girls who where born naturally. And, it would be very expensive to implement a separation process.
Just what is cloning, and how does it work?
When scientists explain the practice of cloning livestock, they describe clones as genetic twins born at different times. Cloning companies say it's just another reproductive technology, such as artificial insemination.
"The lead cow (the one in front) gets whipped the most." - African Proverb, Zulu.
Here is how cloning works: Scientists take an immature egg, usually from a cow that went to the slaughterhouse, and remove the nucleus. They add DNA from a designated cow, often taken from the skin cell of an ear, and a tiny electric shock coaxes the egg to start dividing and grow into a copy of the original animal. The egg is then implanted into a surrogate animal for gestation and birth, and the egg subsequently grows into a fetus.
The term "clone" is derived from the Greek word for "twig, branch," referring to the process whereby a new plant can be created from a twig. In horticulture, the spelling c-l-o-n was used until the twentieth century; the final "e" came into use to indicate the vowel sound is a "long o" instead of a "short o." Since the term entered the popular lexicon in a more general context, the spelling c-l-o-n-e has been used exclusively.
Hundreds of cloned animals exist today but the number of different species is limited. Attempts at cloning certain species such as monkeys, chickens, horses and dogs, have not been documented.
These early stages of reproductive cloning have been expensive and highly inefficient. More than 90 percent of cloning attempts have reportedly failed to produce viable offspring. More than 100 nuclear transfer procedures could be required to produce one viable clone. In addition to low success rates, cloned animals tend to have more compromised immune function and higher rates of infection, tumor growth and other disorders. Japanese studies have shown that cloned mice live in poor health and die early. About a third of the cloned calves born alive have died young and many of them were abnormally large. Many cloned animals have not lived long enough to generate acceptable data that could inform scientists about how clones age. Appearing healthy at a young age, unfortunately, is not a good indicator of long term survival. Clones have been known to die mysteriously.