WHERE'S THE GRAIN? The 7 billion livestock animals in the United States consume five times as much grain as is consumed directly by the entire American population.
HERBIVORES ON THE HOOF. Each year an estimated 41 million tons of plant protein is fed to U.S. livestock to produce an estimated 7 million tons of animal protein for human consumption. About 26 million tons of the livestock feed comes from grains and 15 million tons from forage crops. For every kilogram of high-quality animal protein produced, livestock are fed nearly 6 kg of plant protein.
FOSSIL FUEL TO FOOD FUEL. On average, animal protein production in the U.S. requires 28 kilocalories (kcal) for every kcal of protein produced for human consumption. Beef and lamb are the most costly, in terms of fossil fuel energy input to protein output at 54:1 and 50:1, respectively. Turkey and chicken meat production are the most efficient (13:1 and 4:1, respectively). Grain production, on average, requires 3.3 kcal of fossil fuel for every kcal of protein produced. The U.S. now imports about 54 percent of its oil; by the year 2015, that import figure is expected to rise to 100 percent.
THIRSTY PRODUCTION SYSTEMS. U.S. agriculture accounts for 87 percent of all the fresh water consumed each year. Livestock directly use only 1.3 percent of that water. But when the water required for forage and grain production is included, livestock's water usage rises dramatically. Every kilogram of beef produced takes 100,000 liters of water. Some 900 liters of water go into producing a kilogram of wheat. Potatoes are even less "thirsty," at 500 liters per kilogram.
HOME ON THE RANGE. More than 302 million hectares of land are devoted to producing feed for the U.S. livestock population -- about 272 million hectares in pasture and about 30 million hectares for cultivated feed grains.
DISAPPEARING SOIL. About 90 percent of U.S. cropland is losing soil -- to wind and water erosion -- at 13 times above the sustainable rate. Soil loss is most severe in some of the richest farming areas; Iowa loses topsoil at 30 times the rate of soil formation. Iowa has lost one-half its topsoil in only 150 years of farming -- soil that took thousands of years to form.
PLENTY OF PROTEIN: Nearly 7 million tons (metric) of animal protein is produced annually in the U.S. -- enough to supply every American man, woman and child with 75 grams of animal protein a day. With the addition of 34 grams of available plant protein, a total of 109 grams of protein is available per capita. The RDA (recommended daily allowance) per adult per day is 56 grams of protein for a mixed diet.
OUT TO PASTURE. If all the U.S. grain now fed to livestock were exported and if cattlemen switched to grass-fed production systems, less beef would be available and animal protein in the average American diet would drop from 75 grams to 29 grams per day. That, plus current levels of plant-protein consumption, would still yield more than the RDA for protein.
From "Livestock Production: Energy Inputs and the Environment"
By David Pimentel
source: Cornell University Science News