Animal Polluters

Industry and the habits of urban man dominate the attention of environmentalists, but these familiar targets have rustic, yet serious, competition. The nation's 50 million pigs, 38 million cattle and 350 million chickens threaten other forms of life with vast quantities of bodily wastes. Livestock produce two billion tons of manure in the U.S. each year. In some states the situation has become so alarming that farmers, cattlemen and scientists are frantically searching for a way to clean up the landscape.

The problem is space. Just 15 years ago, the average steer in the U.S. had about 86,000 sq. ft. of open range to roam in. The land could absorb excretion; natural processes converted it to fertilizer. Today the steer is likely to be crowded into outdoor feed lots with only 200 sq. ft. of living space. Feed lots, where livestock is scientifically bred and fattened for slaughter, were rare in the early 1950s. Now there are 256,000 for cattle alone, and a single facility containing 50,000 head is not uncommon. Since these feed lots are concentrated near cities, transporting manure for fertilizer to rural areas is not economical.

Dying Waters. Because most feed lots are situated near lakes, rivers or streams so that livestock can be watered, rain can cause heavy manure runoffs that in turn pollute the water supply. Waste materials equivalent to those produced by 100 million people, for example, have been measured in the Missouri River between Omaha and Kansas City. Such enormous manure runoffs produce disease-carrying bacteria and have so increased the nitrate and phosphate levels in some waterways that algae proliferate, choking off other forms of life. Toxic elements in manure are believed responsible for killing 1,500,000 game fish in nine states in 1968.

The problem of animal waste disposal, of course, is not confined to cattle. Dogs do their part in dirtying cities (TIME, July 20), and pigs and chickens add to the problem in the country. Pigs are still bred on some 1,000,000 farms, and more than 80 million are sold each year. Broiler production soared from 630 million birds in 1950 to about 2.6 billion in 1967. Confined like cattle, pigs and chickens produce mountains of wastes.

Solutions to the problem are only beginning to emerge now that some obvious possibilities have proved impractical. Transporting manure from feed lots to burial pits or storage bins is expensive and difficult. Burning it only increases air pollution and drying it takes up too much space. A more promising approach is to reduce each animal's excretion. Farmland Industries of Kansas City, Mo., has developed grain-sized plastic tabs that, once eaten by a cow, lodge in one of its stomachs, the rumen. There they take the place of roughage, reducing the animal's need for hay. Such cattle subsequently produce up to 40% less manure than those fed conventionally. Another scheme calls for injecting manure with special bacteria to hasten decomposition.

Manure has been used as a fertilizer for centuries. It is currently out of favor, however, because chemicals are cheaper and more easily transportable. Reseachers now claim to have found a way to restore manure to its previous use. In Guymon, Okla., the excrement of 36,000 cattle is collected in settling ponds, and the suspended effluents are piped underground to a 320-acre plot about a mile away. The enriched fertilizer is absorbed into the ground. Other scientists have suggested recycling chicken manure, which has a high nutritional value, drying it and feeding it to chickens and cattle. In one pilot study, sheep and steers took readily to a combination of cattle manure and hay.

For a cattleman with adequate financial resources, such schemes may be workable. Bert A. Getz, a Chicago farmer-businessman, has built a modern indoor feed lot in Marengo, Ill., that is both economical to operate and sparing of the environment. As many as 600 cattle are fed from a conveyor belt in a $125,000 barn. The floor is made of wood slats, spaced so that manure and urine fall into vats beneath. Twice a year the solution is collected and pumped out of the barn to fertilize 250 acres of land.

Getz's operation is a worthy model, but such methods are uneconomical for feed-lot operators with very large herds. Until a system is worked out whereby the cost of waste treatment is subsidized by the Government or passed on to the consumer, animal pollution will remain a difficult environmental problem.

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