Agriculture and Environment: Beef
Environmental Impacts of Production: Production of Feed Grains
One of the major impacts of the beef industry occurs indirectly, through the production of grain used to feed cattle.
The production of feed grains generates significant habitat conversion, soil degradation, water pollution and other environmental impacts.
Consuming 1/3rd of the total cereal harvest
Competition for food resources (i.e., raising grain for cattle feed versus human food) is a serious concern about beef production. Globally, one-third of the world's cereal harvest (wheat, corn, rice) is fed to farm animals.
While the use of feed is not broken out by type of animal, it is clear that a significant portion is used to feed cattle. In the United States some 95% of soybean meal is used as livestock feed. In addition, the U.S. beef industry utilised about 11% of the U.S. corn supply in 1992. In pursuit of a better quality end-product
The switch from grass to feed grain finishing results in a more consistent product even when starting out with inferior animals or genetics. Consequently, the beef herds in the United States, for example, have shifted markedly away from genetically superior meat producers such as Angus and Hereford, which dominated United States markets in the 1950s, until today, when they represent less than half of all beef cattle.
Hardier species, inferior quality meat
More and more, beef cattle are hardier species, but their meat is of inferior quality. Given that most beef is used for hamburger this is not a serious problem. These hardy animals can tolerate more heat, less water, and a wider range of less nutritious vegetation. This change in genetics of the beef cattle herd has resulted in the expansion of pasture-based beef production into harsher and more marginal, biodiverse, and ecologically fragile areas.
Tradeoffs between various beef production systems
Data from Sweden illustrate some of the tradeoffs between the different beef production systems (e.g., grass-fed, grain-fed feedlot-fattened, or a combination of the two) and their overall impacts. Calves produced through intensive feedlot feeding systems can be slaughtered in twelve to thirteen months at a weight of 450-475 kilograms live weight.
Fed protein-rich concentrates, such animals gain more than 1 kilogram per day and can be produced with less total feed (25 megacalories per kilogram slaughtered weight). By contrast, grass-fed beef live longer and eat more roughage (grass, hay, and silage); these animals reach 525-550 kilograms (live weight) at the time of slaughter, but this requires about 18 months.
Because they take longer to reach slaughter size, their overall feed consumption is somewhat higher (35 megacalories per kilogram slaughtered weight) than that of feedlot-produced beef (Tengnas and Nilsson 2002). The feed for grass-fed animals is cheaper, more locally produced roughage.
