US | mysterious animal deaths Here's What Killed Those Dead Cows Toxic sweet potatoes were included in their feed By Evann Gastaldo Posted Jan 31, 2011 1:38 PM CST Copied The cows were done in by sweet potatoes. (?karlfrankowski) The latest mass animal death mystery has been solved: The 200 cows that dropped dead in a Wisconsin pasture two weeks ago were killed by, of all things, moldy sweet potatoes. The farmer who owned them originally suspected disease, but investigators ruled that out and determined the cows were likely poisoned by the spoiled sweet potatoes, which were included in their feed, Aol News reports. Click here for more. Read These Next NFL star's routine drug test revealed a stunning diagnosis. A beach massacre at a Jewish event in Australia killed 12. Peggy Noonan: Kirk assassination starting to look 'epochal.' Supernova will be visible in daytime after star eats its neighbor. Report an error