U.S. Government Animal Mutilation Documents: 

“FBI Records: The Vault: Animal Mutilation”

(Federal Bureau of Investigation, Washington, D.C.)

The web page contains the following two UFO-related newspaper articles: “Are UFO sightings and mutilations related? – Mutilated livestock, helicopters and UFOs source of wonder, worry” 
(29 August 1974, Daily Tribune, Hastings, Nebraska) (Part 1 of 5), “New Findings Deepen Mystery of Mutilations” (13 December 1978, Albuquerque Journal, New Mexico) (Part 3 of 5):

http://vault.fbi.gov/Animal%20Mutilation/

(wikimedia.org image)