Smithfield Foods Inc. says it has fired two employees and their supervisor for mistreating pigs at a Virginia farm, according to the Associated Press. The Humane Society of the United States last week released results from an undercover investigation that showed breeding pigs abused and crammed into small gestation crates at the farm of livestock production subsidiary Murphy-Brown. The company did an internal investigation and announced on its website that three workers were fired for violating the company''s animal welfare policies. Smithfield Foods is the world''s largest pork producer. The Humane Society has called on Smithfield to renew its commitment to phasing out the gestation crates, which severely limit pigs'' movement.