which of the following are called key industry animals

1. autotrphs
2. decomposers
3. herbivors
4. top carnivores

Factory farming is widespread in developed nations. According to the Worldwatch Institute, as of 2006, 74 percent of the world's poultry, 43 percent of beef, and 68 percent of eggs were produced this way. In the U.S., as of 2000 four companies produced 81 percent of cows, 73 percent of sheep, 60 percent of pigs, and 50 percent of chickens and according to its National Pork Producers Council, 80 million of its 95 million pigs slaughtered each year are reared in industrial settings.