Police have launched an investigation after pregnant cows were intentionally poisoned at a farm at Ham, near Great Bedwyn.
Police say that overnight between Wednesday and Thursday, April 27 and 28, an unknown poisonous substance was added to water troughs within an open barn containing 67 in-calf beef cattle.
By Friday morning 10 cows were dead, along with unborn calves.
Anyone with information is urged to call Wiltshire Police on 101 or Crimestoppers on 0800 555 111.