Two videos here examine some brief evidence on cattle mutilations which have taken place mainly on the American continents.

Argentinian Images of Cattle Mutilations 

Jaques Valles Comments on the Evidence 

The book cover image below is Jim Hickman's book. Far better to check out the books and website material of the likes of Linda Howe instead as Jim tends to border on telling us not to leave out homes due to the nastiness of  many 'alien' scenarios. His book/presentation called 'A Blood Soaked Paper Trail' on human mutilations alledgedly by non-terrestrial entities was deliberately over the top and disturbing. We have this on video and can seed it via torrent but do not share his conclusions and paranoia.

As a species we are not currently equipped to conceptually view this phenomena so analysis often disappears into layers of fear and misunderstanding. In fact when we look into this area it becomes fairly obvious that the planet and it's inhabitants are what Charles Fort termed 'property' - cattle mutilations are part of this scenario but brought on by our species irresponsibility more than a deliberately disturbing program by off-world entities.