While [Peter] Singer's and [Tom] Regan's theoretical approaches are fundamentally different, they converge on a number of important points. First, both argue that all conscious, sentient animals with desires and interests deserve equal moral consideration (regardless of whether these animals are human or nonhuman). The practical implications of their views also converge. Both approaches entail that most contemporary uses of animals—factory farming of animals for meat, eggs, and milk; animal experimentation; use of animals for entertainment in zoos and circuses; hunting and trapping animals in the wild; and so on—are morally unjustified and should be eliminated. Both authors consider the attitudes of most people toward animals to be nothing more than an arbitrary prejudice in favor of our own kind that many now refer to pejoratively as "speciesism" (a term coined by Richard Ryder). Singer, in particular, likens speciesism to racism and sexism, and uses the analogy to argue that a new liberation movement is needed to combat this deep-seated but unjustified prejudice and the many forms of animal exploitation that flow from it.
(Mylan Engel Jr and Kathie Jenni, The Philosophy of Animal Rights: A Brief Introduction for Students and Teachers [New York: Lantern Books, 2010], 27)