Factory farming involves① keeping farm animals inside buildings to increase the production of meat or eggs. According to an institute②， “74% of the world ’s poultry③， 43% of its beef and 68% of its eggs are produced in this way.”
本部分引出工厂化养殖话题。
The main argument for factory farming is that, apart from④ being a lot cheaper than traditional or organic farming, it provides more food for a world population that has already reached seven billion⑤， according to the United Nations. As factory farms do not use many workers, the costs are low and the production is high. Moreover, factoryfarmed animals suffer from fewer diseases than those living outside.
On the other hand, opponents⑥ of factory farming say that it is cruel⑦ to the animals. For instance⑧， many farm animals are kept in small spaces where they can hardly move. People who fight for animal rights claim⑨ that these animals suffer terrible stress. In addition to this, factory farming has a negative impact on the environment because it creates a lot of waste products, and uses a lot of chemicals⑩ to control insects and drugs? to treat diseases (UK Farming Today, 2013)．
