World Day Against Speciesism is observed worldwide every June 5. This annual event was initiated by animal rights advocates to highlight the concept of speciesism, which refers to the assignment of different rights and values based solely on species, akin to racism or sexism. The term was first introduced by British psychologist Richard D. Ryder and popularized by Australian philosopher Peter Singer in his book "Animal Liberation," published in 1975. Advocates argue that speciesism is a form of prejudice, claiming that the use of animals for food, clothing, scientific experiments, and entertainment constitutes discrimination and abuse. Organizations such as People for the Ethical Treatment of Animals (PETA) and the Farm Animal Rights Movement (FARM) support this observance, promoting the idea that speciesism has no place in a civilized society.