Police arrived at the property near Narromine to find the slaughtered cow with only its head and organs left behind.

The crime has left a calf without its mother and a farmer devastated.

Farmer Lara Quealy said she is heartbroken and angry and can't understand why anyone would want to be so cruel to a defence-less animal.

“I was heartbroken when I found this poor little calf sitting faithfully with what's left of his mother, he is now orphaned and will have to be bottle fed,” she said.

"No one expects to find one of their breeding cows slaughtered while on agistment.

"We have battled with the drought and reduced our cattle numbers to only our core breeding herd; she was a young stud cow and the last of her genetic line.

"The police were as shocked as I was, I can't believe someone would just randomly shoot a cow to start with but then to leave the calf sitting there is just terrible, and it's hard to think that anyone could be so cold and callous.

MAP: The area where the crime occurred

"Farmers are easy targets for this type of crime because we are isolated but people need to be aware that this type of thing occurs, we need to be tough on these people if they are caught."

Police Sergeant Michael Smith said the only way police can catch the perpetrators of these crimes is if people report them when they occur.

"Often farmers don't report these types of crimes, but we encourage them to because if we don't know about it, we can't do anything about it," Sergeant Smith said.

"This crime is very rare I haven't seen anything like this in my time, we see mostly property crime such as theft.

“Something so violent and senseless against an animal is rare and a cause of great concern to police."

Police are calling for any witnesses or anyone with information to contact them on 6889 1444 or at Crime Stoppers on 1800 333 000.