DES MOINES (AP) --- An animal rights organization is getting help from actress Bea Arthur in calling attention to what it says is the abuse of cattle at a kosher slaughterhouse in Postville. People for the Ethical Treatment of Animals, or PETA, alleges that Agriprocessors Inc. has violated state law that requires the use of humane methods of slaughter. PETA recently filed complaints with federal officials and the state, calling for the prosecution of Agriprocessors and the Orthodox Union, an international kosher certification agency. ADVERTISEMENT HOW TO ADVERTISE » MARKETPLACE » In a letter sent Thursday to Orthodox Union leaders,...