The agencies of the U.S. Department of Agriculture publish many reports that verify the accuracy of the information provided here. Following are the links to a number of these reports.
Sheep and Goat Death Loss
Cattle Death Loss
Sheep and Lamb Predator Death Loss in the United States, 2004
Wildlife Services State-by-State Reports - Click on your state and then click on 'More'.
Wildlife Services' Fiscal Year 2007 Livestock Funding
Controlling Wildlife Damage on Public Lands
Wildlife Management Information