Before World War II, most Americans had never eaten corn-fed beef. Raised on pasture, cattle reared before the 1950s usually took two or three years to be ready for the slaughterhouse. Steers were fed grain only occasionally and in small quantities, and farmers tended to use corn as a supplement—not a staple—of their livestock’s diets.
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But as American corn production skyrocketed in the post-War era, and as the economic boom of the 1950s prompted higher consumer demand for meat, farmers and ranchers turned to a new practice: fattening their cattle on corn. Cheaper and more efficient than grass, corn enabled cattle to be brought to market in as few as 15 months. Moreover, it allowed farmers to feed cattle in confined pens or lots, reducing ranchers’ land costs and limiting their risk of losing livestock to predators and bad weather. With cheaper feed in the equation, beef prices fell, and Americans began to purchase more and more beef, most of it corn-fed. By 1960, Americans ate a yearly average of more than 66 pounds of beef each. By 1975, that number had grown to 88.5 pounds of beef per person, per year.
In 2008, corn-fed cattle are the norm. While most cattle still begin their lives grazing on grass, the vast majority—an estimated three-quarters of them, according to the U.S. Department of Agriculture—are “finished,” or fattened for market, in feedlots. There, they spend three to six months eating a diet composed of 70 to 90 percent corn.
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While corn feeding has kept the cost of beef low, it’s raised eyebrows among nutritionists and environmentalists the world over. Health experts represented by the Union of Concerned Scientists and the University of California, among other groups, point out that grain-raised beef is higher in unhealthy saturated fats than its grass-fed counterpart. In addition, it’s more likely to contain muscle-building hormones whose safety for humans remains under debate.
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Further, the widespread use of antibiotics among feedlot operators, who are compelled to administer the drugs in order to protect their animals from disease, has prompted concern among public health advocates. In 2007, reports published by the National Institutes of Health in the journal Environmental Health Perspectives have questioned whether the antimicrobial medicines regularly fed to large populations of livestock are encouraging the development of drug-resistant germs, which could make human antibiotics less effective.
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On the ecological front, feedlots pose similar challenges. As the National Cattleman’s Beef Association puts it, “Feedlot owners must be very attentive to the environment.” And no wonder: U.S. farm animals produce an average of 100,000 metric tons of manure every minute, much of which is held near feedlots in large lagoons of waste. Without proper treatment and disposal, these lagoons can pollute nearby watersheds, contribute to ecologically destructive algae blooms in neighboring waters and release the ammonia that can lead to acid rain. Even more troubling, overburdened lagoons can leak millions of gallons of waste into streams and rivers. Such spills have already occurred in a dozen U.S. states.
http://www.pbs.org/independentlens/kingcorn/cows.html
