Casey Affleck is going back to school on Tuesday (18Sep12) to hand out dairy-free milk and ice cream to students at his alma mater.

The Ocean's Eleven star will greet kids at Cambridge Rindge and Latin School in Boston, Massachusetts as they arrive at school with animal-friendly treats as part of People for the Ethical Treatment of Animals' launch of a hard-hitting new video about the dehorning of dairy calves.

Vegan Affleck is hoping the short film, which he narrates and appears in, will persuade more and more people to boycott dairy products as a protest.

He tells WENN, "Cows and calves struggle desperately during dehorning. All these procedures are routinely performed without giving the animals any painkillers whatsoever. You can help stop this inhumane practice by avoiding cow's milk, cheese, and other dairy products."