The ethics of what we eat

"In the United States somewhere between 20 and 40 million birds and mammals are killed for research each year. That may seem like a lot- and it far exceed the number of animals killed for their fur, let alone the relatively tiny number used in circuses-but even the figure of 40 million represents less than two days’ toll in America’s slaughterhouses, which kill around 10 billion each year."
Peter Singer- The Ethics of What we Eat