Friday, June 29, 2007

Hormones and Milk

Dr. Henry Miller, writing in today's NY Times, tells us not to worry about the use of a bovine growth hormone, rBST, to increase milk production in cows:


One way to ease the shortage and lower the prices is to take greater advantage of a proven 13-year-old biological technology that stimulates milk production in dairy cows — a protein called recombinant bovine somatotropin (rBST), or bovine growth hormone. The protein, produced naturally by a cow’s pituitary, is one of the substances that control its milk production. It can be made in large quantities with gene-splicing (recombinant DNA) techniques. The gene-spliced and natural versions are identical.

When rBST is injected into cows, their digestive systems become more efficient at converting feed to milk. It induces the average cow, which produces about eight gallons of milk each day, to make nearly a gallon more. More feed, water, barn space and grazing land are devoted to milk production, rather than other aspects of bovine metabolism, so that you get seven cows’ worth of milk from six.

This may not seem like a big deal, but when applied widely the effects are profound. For every million cows treated with rBST each year, 6.6 billion gallons of water (enough to supply 26,000 homes) are conserved, according to Monsanto, which makes rBST. With much of the nation enduring a drought and many cities in the West experiencing water shortages, this is a significant benefit.

The amount of animal feed consumed each year by those million rBST-supplemented cows is reduced by more than three billion pounds. This helps to keep the lid on corn prices, even as much of the nation’s corn harvest is diverted to producing ethanol for cars. And the amount of land required to raise the cattle and grow their food is reduced by more than 417 square miles.

At the same time, more than 5.5 million gallons of gasoline and diesel fuel (enough to power 8,800 homes) are saved, greenhouse gas emissions are lowered by 30,000 metric tons (because fewer cows means less methane produced by bovine intestinal tracts), and manure production is decreased by about 3.6 million tons, reducing the chances of runoff getting into waterways and groundwater.

Comprehensive studies by academics and government regulatory agencies around the world have found no differences in the composition of milk or meat from rBST-supplemented cows.

He goes on to dispute assertions that rbST isn't safe for people, and concludes thusly:

Cynical activists have unfairly stigmatized a scientifically proven product that has consistently delivered economic and environmental benefits to dairy farmers and consumers. In a more rational world, they would embrace — and enlightened consumers would demand — milk with a label that boasted, “A Proud Product of rBST-Supplemented Cows.”

That will never happen. Why? Because for all of the supposed benefits, there are some significant drawbacks that Dr. Miller fails to mention. It's true that no study shows that rBST can be detected in milk produced by cows given the hormone. However, Dr. Miller leaves out the fact that cows treated with rBST are not as healthy, and are more prone to conditions that require treatment with antibiotics than cows that are not treated with rBST. Now you may not care much about the welfare of the cows that produce milk, but the the antibiotics used to treat them certainly do survive the pasteurization process and end up in the milk we drink, thus promoting antiobiotic resistence not only in cows but in us as well. Those antibiotics-and hormones-also end up in groundwater, so that even if you're not getting them in your milk, you might be getting them in the water you drink. And as you can well imagine, drug companies-like Monsanto, which produces rBST-are not encouraging dairy farmers to use the hormone out of the goodness of their hearts.

The problem is not one of bovine milk production. The problem is one of unsustainable factory farming. There's nothing wrong with enjoying a glass of milk. Humans have been consuming the products of other animals for as long as they and those animals have been around. But we're not entitled to cheap milk ("got milk?" campaigns notwithstanding) and our efforts to keep it cheap and plentiful are damaging to the environment, damaging to us, and harmful and cruel to the cows we use to produce the milk. All of the benefits to the environment that Dr. Miller touts above as a benefit or rBST could just as easily be obtained by drinking less milk. If reducing the use of hormones in cows reduces the use of antiobiotics and raises the price of milk, thus reducing our exposure to antibiotics and growth hormones, this is a good thing for us (and the cows.)

UPDATE: As they say, great minds think alike.

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