A study by the LSU AgCenter finds feral hogs have caused at least $30 million in damage to crops on Louisiana farms in 2013.

AgCenter economist Shaun Tanger has been gathering data for more than a year from Louisiana farmers about hog activity and damage, which ranges from rooting up and eating crops to damaging farm equipment. The hogs can also spread fatal diseases to wildlife and livestock.

The study, released Monday, finds the 2013 Louisiana soybean crop suffered more than $9 million worth of hog damage. Hay producers lost about $7 million, while the rice and corn industries both saw about $5 million in damage.

Farmers also reported hogs interfering with livestock operations and damaging equipment and levees.