Macarthur police Senior Constable David Rook said police were called to a Tarrone property on Saturday after a cow was found dead.

"An officer spoke to the farm manager who showed him a Friesian cow that had apparently been shot in a paddock off Tarrone Lane," he said.

"The animal was shot well into the paddock and appears to have suffered a single gunshot wound to the flank. Neighbours heard a vehicle in the area in the early evening but that may not be related."

Senior Constable Rook said the property was a dairy farm with many cows.

"There are also workers who live on the property and it is timely to reminder shooters that a set of eyes in a paddock may not be a fox and to check their targets. Such random shooting is extremely dangerous," he said.

"The penalties for shooting across land used for primary production or near people are huge and will result in loss of a shooter's licence, loss of firearms and fines of many thousands of dollars. The animal was valued at $1500."

Anyone with information is requested to contact the Macarthur police station or Crime Stoppers on 1800 333 000.