It used to take five years for a cow to reach its mature weight, ready for slaughter and processing. Today, since the structures and processes of feed yards have been perfected, that has been reduced to less than 18 months.

Such speed requires growth hormones and antibiotics in cows’ diets, and efficient feedlot architecture. Farmers can turn to reports to help calculate the maximum number of cattle that can fit in each pen, the minimum size of run-off channels that carry away thousands of tons of urine and manure, and the composition of chemicals needed to break down the waste as it collects in lagoons and drains into the soil. Different chemical mixes explain the varying toxic hues of each lagoon.

http://www.latimes.com/opinion/op-ed/la-oe-marks-on-the-land-html-20151222-htmlstory.html