Brave New World

Genetic Engineering, rBGH and Mad Cow Disease

Oddly enough, one reason cows are eating more of each other these days has to do with recombinant bovine growth hormone (rBGH), a synthetic form of the controversial hormone the dairy industry is employing to stimulate milk production. Marketed under the name “Posilac,” Monsanto’s rBGH is the first genetically engineered food product to win FDA approval. Injected into a cow’s pituitary gland every two weeks, rBGH (also known as BST, or bovine somatotropin) can increase milk output by up to 25 percent.

But in order for rBGH to be optimally effective, cows need larger quantities of protein. And because corn prices are high, factory farms buy the cheapest form of protein they can get: rendered animal carcasses.

rBGH is also popular with the industry because it increases the lean meat content of the dairy cows that end up on meat counters after their lactating days are over. But it is known to cause severe cases of mastitis (infections of the udder), which need to be treated with heavy doses of antibiotics. According to Alexander Cockburn, writing in New Statesman, “The antibiotic injected into the cow passes on to the human consumer, where it can attack the immune system.”

Cockburn says that rBGH works by stimulating production of an insulin-like growth factor known as IGF-1, which is also found—with the same molecular structure—in humans. And that, reports Inter Press Service, increases the likelihood of IGF-1 transmission through milk and meat consumption. High IGF-1 levels are believed to be a cause in humans of acromegaly, a disease that causes an abnormal enlargement of nose, hands, feet and chin. It’s also been linked to colon, prostate, ovarian and breast cancer. Inter Press adds that use of hormones in cow production has also led to earlier onset of puberty, “and girls who menstruate before the age of 12 have a higher risk of contracting breast cancer later.”

The possible connection between rBGH and mad cow disease was first made in 1993 by Michael Hansen, a research associate at the Consumer Policy Institute. Hansen points out that the American form of bovine spongiform encephalopathy (BSE) has an important difference from its more dramatic British variant: The infected cows here just collapse and die; they don’t exhibit drooling and staggering symptoms. Hansen makes a link to a well-known sight at American feedlots: the “downer” cow, which falls, unable to get up, on its way to the slaughterhouse. These rBGH-fed downer cows are invariably rendered and fed back to other cows. If “downers” do have BSE, it would be difficult to devise a better way to spread the disease throughout the U.S. cattle population.

Monsanto, which invested $1 billion in Posilac, obtained FDA approval for rBGH in 1993, and since then has waged an all-out war to keep smaller dairy farmers from labeling their products “rBGH-free.” In fact, it’s currently illegal for farmers to ship products with “rBGH-free” labels across state lines, because of the potential impact on milk sales.

Monsanto’s CEO Robert Shapiro defends rBGH on population grounds. “There is a need for agricultural productivity and increased dairy products,” he says. “We will need to double production if we want to feed all the new people who will be joining us.” Shapiro also says, “The milk produced is the same milk as that from cows that are not being treated.”

But claims of a milk shortage are rather hard to justify when the U.S. government spends $1 billion a year buying up surplus milk (which it then churns into butter). And there are signs of resistance to Monsanto’s wonder drug. A 1995 poll in the industry magazine Dairy Today found that 40 percent of farmers polled had stopped using Posilac, and 23 percent thought it harmed their cattle.