Air pollution, water contamination
The direct impacts of cattle feeding include contributions to air pollution through methane, odours, and dust, and to pollution of surface and ground water through nutrient loading from improper handling of manure. In addition, other environmental impacts such as the use of antibiotics can be intensified given the large concentrations of animals in a confined space.
100,000 metric tons of manure per minute!
About 1.4 billion metric tons of solid manure are produced by U.S. farm animals each year - 130 times the amount produced by the human population. Put another way, US animal feedlots produce 100,000 metric tons of manure per minute. This figure includes pigs and chickens as well as cattle, but even so cattle are the single largest source.
In Texas 7.5 million head of cattle in feedlots consume more than 7 million metric tons of feed containing more than 150,000 metric tons of nitrogen and 25,000 metric tons of phosphorous.
It would take 8,000 hectares of corn silage (or a similar crop) to absorb the manure from a feedlot with 50,000 head of cattle (Conner et al. 1999). If the manure cannot be added as a soil amendment, it has to be treated and disposed of another way to avoid contaminating land or water.
Disposal without treatment = water pollution, algal blooms, acid rains
Disposal of organic wastes without proper treatment leads to the pollution of water resources. Eutrophication (nutrient enrichment) of water systems can cause large-scale algal blooms that kill fish and other aquatic life. Such serious situations have been encountered in northwest Europe and off the East Coast of the United States. In addition, ammonia released from manure and slurry can, through its interaction with sulphuric and nitric acids, contribute to acid rain.
