How often do livestock deliberately kill farmers?

An Oregon farmer was eaten by his hogs on Wednesday. The 70-year-old Vietnam veteran had gone to feed the animals in the morning, and his family found his dentures and scattered remains in the hog pen several hours later. Authorities are trying to determine whether the pigs deliberately killed the man. Do livestock intentionally kill their owners?

Yes. Cattle kill approximately 22 Americans per year nationwide, and the animals deliberately attack their victims in 75 percent of those cases, according to a 2009 study. About one-third of bovine killers have a history of aggressive behavior.