Speciesism is an ideology that considers the lives and interests of animals as not worthy of respect simply because they belong to another species.

The notion of speciesism can be understood by analogy with racism or sexism; speciesism tends to place animals outside the range of moral consideration. Anti-speciesism is simply the rejection of the use of the species of a sentient being as an argument for disregarding its interests and its life.

Links:
World Day for the End of Speciesism