Animal rights group PETA is calling on shearers to report drug use following an investigation which exposed disturbing video footage of sheep being stomped on, brutally cut and bashed with hammers.

The group has launched a billboard in Horsham which urged people to report drug and animal abuse in shearing sheds.

The PETA billboard in Horsham.

The ad features the gaunt face of a man beside the words: "Dave has been up on ice for three days. Shearing and drugs don't mix. If you see something, say something. Always report animal abuse."

The Victorian Farmers Federation is "flabbergasted" by the billboard, and accused PETA of targeting shearers to push its political agenda.