Meat Production Methods
We have seen that in order to remain economically viable and feed large numbers of people, modern agriculture in the United States has had to become larger and more mechanized. As agriculture developed to supply meat and poultry to large numbers of people at a low cost, the primary objective became implementing methods that promoted the faster growth of animals. Methods of meat production include concentrated animal feeding operations (CAFOs), also called feedlots, and free-range grazing. Meat production is less efficient than agriculture; it takes approximately 20 times more land to produce the same amount of calories from meat as plants.
In 2016, according to the U.S. Department of Agriculture (USDA), roughly 150 million animals were slaughtered for beef, pork and lamb, along with billions of chickens, turkeys and ducks. Many of these animals were raised in CAFOs. Concentrated animal feeding operations (CAFOs) are used as a way to quickly get livestock ready for slaughter. They are large indoor or outdoor structures designed for maximum output. They tend to be crowded, and animals are fed grains or feed that are not as suitable as grass. This type of high-density animal farming is used for beef cattle, dairy cows, hogs and poultry, all of which are confined or allowed very little movement during all or part of their life cycle. A CAFO may contain as many as 2,500 hogs or 50,000 turkeys in a single building. By keeping animals confined, farmers minimize land costs, improve feeding efficiency, and increase the fraction of food energy that goes into the production of animal body mass. Keeping animals confined to a small space, which is criticized by some on ethical grounds, ensures that less energy is expended by the animal in activities such as moving around and the increased respiration that will result. The animals are given antibiotics and nutrient supplements to reduce the adverse health effects and diseases, which would normally be high in such highly concentrated animal populations.
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High-density animal farming has many environmental and health consequences. There is evidence that antibiotics given to confined animals are contributing to an increase in antibiotic-resistant strains of microorganisms that affect humans. Additionally, feedlots generate a large amount of organic waste, which can contaminate ground and surface water. Waste-disposal is a serious problem. An average CAFO produces over 2,000 tons of manure annually, or about as much as a town of 5,000 people would produce. The waste is used to fertilize nearby agriculture fields, but if over-applied, as is usually the case, it can cause the same nutrient runoff problems as synthetic fertilizer. Sometimes animal wastes are stored in lagoons adjacent to feedlots, but during heavy rainstorms (or hurricanes in eastern NC), runoff from these lagoons can contaminate nearby waterways. Animal wastes have also been dumped, either inadvertently or intentionally, into natural waters. The U.S. Environmental Protection Agency (EPA) has concluded that chicken, hog and cattle waste has caused pollution along 56,000 km (35,000 miles) of rivers in 22 states and has caused some degree of groundwater contamination in 17 states.
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The use of feedlots are less expensive than other methods, which can keep costs to consumers down, but there are methods for animal production that have a lower environmental impact. Not all meat comes from CAFOs. Free-range chicken and beef are becoming increasingly popular in the United States. Some people find it more ethically acceptable to eat a chicken or cow that has wandered free than one that has spent its entire life confined in a small space. Free-range meat, if properly produced, is more likely to be sustainable than meat produced in CAFOs. Because these free-range animals are not as likely to spread disease as those kept in close quarters, the use of antibiotics and other medications can be reduced or eliminated. The animals graze or feed on the NPP of the land, eating grass during their entire lifecycle with little or no supplemental feeding, so less fossil fuel goes into the raising of free-range meat. Finally, manure and urine are dispersed over the range area and are naturally processed by detritivores and decomposers in the soil. As a result, there is no need to treat and dispose of massive quantities of manure. Organic waste from these animals act as fertilizer. On the negative side, free-range operations use more land than CAFOs do, and the cost of meat produced using this technique is usually significantly higher.
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Overgrazing occurs when too many animals feed on a particular area of land. Overgrazing causes loss of vegetation, which leads to soil erosion. This usually occurs in grasslands where overgrazing leaves bare patches where roots no longer hold the soil together. When this is combined with the action of rain and wind, the bare patches become bigger and soil is removed from the area. As soil formation is a slow process, it will take many years for a region to recover. Overgrazing can also cause desertification. Desertification is the degradation of low precipitation regions toward being increasingly arid until they become deserts.
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Less consumption of meat could reduce CO2, methane and N2O emissions, conserve water, reduce the use of antibiotics and growth hormones, and improve topsoil. The activities associated with growing, harvesting, processing and preparing food require a great deal of energy. When we consume meat, we also have to keep in mind the amount of energy that went into producing the food for the livestock.
Raising beef requires more resources than growing corn. Let's look at some of the actual numbers.
On farms in the midwestern U.S., a hectare of land yields roughly 370 bushels of corn (150 bushels per acre). A bushel consists of 1,250 ears of corn, and each ear typically contains 80 kilocalories. Assume that a person eats only corn and requires 2,000 kilocalories per day. Although this assumption is not very realistic, it allows an approximation of how much land it would take to feed that person.
The person's food requirement is
2,000 kilocalories/day x 365 days/year = 730,000 kilocalories/year
A hectare of corn produces
370 bushels/hectare x 1,250 ears/bushel x 80 kilocalories/ear = 37,000,000 kilocalories/hectare 730,000,000/year divided by 37,000,000 kilocalories/hectare = 0.02 ha (0.05 acres) of land to feed one person per year
Thus, one person eating only corn can obtain sufficient calories in a year from 0/02 ha (0.05 acres) of land. What if that person ate only beef? It takes about 20 kg of grain to produce 1 kg of beef. So it would take 20 times as much land, or 0.4 ha (1 acre) to feed a person who ate only beef.
What happens if we extend this analysis to a global scale? If Earth has about 1.5 billion ha (3.7 billion acres) of land suitable for growing food, is there sufficient land to feed all 7.7 billion inhabitants of the planet of they all eat a diet of only beef?
7.7 billion people x 0.4 ha/person = 3, 080,000,000 ha
So 3.08 billion ha (7.61 billion acres) would be needed and the answer is no.
