Today's cow may look the same as ever, but inside she's a picture of scientific innovation. Molecular biologists have honed the cow genome to create disease-resistant bovines, and the $36 billion-a-year cattle business in steak, leather, and milk has branched into pharmaceuticals, skin grafts, and replacement heart valves. Regardless of your animal politics, cow byproducts are everywhere - from the ink in high-gloss magazine graphics to the explosives an angry cattle-rights organization might place beneath that magazine's editorial offices, right down to the cinder blocks of the federal prison where those sad individuals would spend the rest of their sorry days. Isn't science amazing! Here, a roundup of the latest in cowtech. - Charles Graeber
The Gas-X Factor
Cow flatulence produces some 80 million tons of methane worldwide a
year - the greenhouse equivalent of 1.7 billion tons of CO2.
Entrepreneurs smell opportunity. By supplementing cattle feed with molasses and urea, the
Virginia-based Global Livestock Group reduces bovine emissions in the third world. GLG
measures the greenhouse savings (using patented ruminant flatulence-monitoring
technology), then sells it as an offset to power companies needing to comply with tighter
greenhouse emissions laws.
Born to be Tender
Three words: supertender filet mignon. That's just one of the genetic traits scientists are
searching for among the 96.7 million cows in the US. (The Simmental was selectively bred
for beef and dairy uses.) Similar research is under way to produce cattle that are resistant
to diseases like foot-and-mouth and mad cow. Cloning technology already allows
researchers to copy prize genetic specimens, as Texas A&M scientists did in 2000 when
they inserted the DNA of a bull with natural disease resistance into an empty donor egg -
a process known as somatic cell nuclear transfer.
Milking, For All It's Worth
The average milk cow produces 7 to 10 gallons a day. One drag on productivity: mastitis,
which costs the US dairy industry around $2 billion a year. This inflammation of the udder,
caused by infection, afflicts 50 percent of all cows at some point. Scientists at the Gene
Evaluation and Mapping Laboratory at the US Department of Agriculture have genetically
engineered heifers designed to produce a protein in their milk to break down
mastitis-causing bacteria. Pasteurization destroys the protein before the milk goes to
market.
Stopping The Madness
Mad cow disease - bovine spongiform encephalopathy - perforates the animal's brain with
billions of tiny holes, much like Creutzfeldt-Jakob disease in humans. Both diseases are
believed to be caused by rogue pied-piper proteins called prions that "seduce" other
proteins into changing shape. Several scientific teams are investigating BSE vaccines, and
researchers at Texas A&M University aim to knock out the bovine prion-facilitating gene
and create BSE-resistant cattle. The 180,000 cases of BSE worldwide were spread by
cattle feed containing prion-infected tissue. The last FDA inspection found that 22 percent
of processing facilities were violating new regulations designed to keep reconstituted
carcasses out of the cow chow. So far, no cases of BSE have been confirmed in the US.
Got Drugs?
By manipulating genes, scientists are transforming cow udders into "bioreactors" and
dairies into drug "pharms." Three big stars have emerged in the bioreactor pasture: PPL
Therapeutics of Edinburgh, Scotland, which has Holstein clones producing Factor VIII (the
blood-clot protein that hemophiliacs lack); Pharming of The Netherlands, which claims to
be working on bioreactor cattle to create human fibrinogen and collagen; and Genzyme
Transgenics of Massachusetts, which has a bioreactor-brewed antithrombin 3, a
blood-thinning agent, in clinical trials in Europe and is manufacturing human serum albumin,
a blood component. Future bioreactor products: cow milk spiked with cancer-fighting
human antibodies that could also be used in portable diagnostic kits.
Stockroom
Tendons from calves contain a collagen protein that, when cultured with human cells
collected from the foreskins of newborns, forms a skinlike tissue. It's the first such product
to gain FDAapproval for treating diabetic and venous leg ulcers. The 3-inch round skin
grafts, called Apligraf, are made by Organogenesis of Massachusetts and have been used
on more than 35,000 patients. Medically useful bovine material is on a rampage. The valves
from bull hearts are harvested in the slaughterhouse and sold as replacements for
worn-out human ones. Cow glands are plucked for processing into human hospital drugs -
everything from bovine heparin, which clears blood clots from catheters and hemodyalizers,
to bovine thrombin, a blood enzyme essential for clotting.