From the Oxford English Dictionary, 2d ed.

speciesism

[f. species n. + -ism.]

Discrimination against or exploitation of certain animal species by human beings, based on an assumption of mankind's superiority.

1975 R. D. Ryder Victims of Sci. 16, I use the word ‘speciesism’ to describe the widespread discrimination that is practised by man against other species... Speciesism and racism both overlook or underestimate the similarities between the discriminator and those discriminated against. 1976 New Society 3 June 544/1 If racism and sexism are wrong, what abut speciesism? Peter Singer apologises for using this graceless term. 1979 Listener 7 June 777/1 ‘Speciesism’ is intended to convey the idea that one animal species, human beings, supposes that it has the right to exploit other species. 1982 Times 8 Apr. 13/1 Animals have rights... There are forms of ‘speciesism’ as corrupting as ‘racism’ or ‘sexism’.

Hence speciesist a. and n.

1975 R. D. Ryder Victims of Sci. 21 The main speciesist defence of cruelty to animals is that mankind benefits—in terms of knowledge, economy or sport, for example. 1977 Daily Tel. 5 May 16 A demonstrating mob of anti-speciesists, perhaps accompanied by species even odder than themselves, may soon be..cawing, roaring and singing..at your door. 1978 Nature 9 Nov. 122/2 Gould is, in general, rather good at puncturing human speciesist vanity, and in particular he will have nothing to do with the myth that evolution represents progress toward man.