Federated Farmers is asking its Ruapehu members to keep stock secured after 15 to 20 cattle were shot by a joint agency operation on Wednesday.
Ruapehu District Council said stock wandering on roads had become a major problem and staff fielded about four calls a week from people reporting near misses or crashes.
The situation reached crisis point this week with cattle wandering on State Highway 37 posing a danger to drivers on the busy road.
Police, Department of Conservation and the council used a helicopter to shoot the cattle, about 15 to 20 animals.
It was the only option left to solve the problem, the council's team compliance officer, Wayne O'Shannessey said.
"The cattle are not wild but due to the state of the surrounding fences and the nearest cattle yard being unsuitable to hold the animals a muster was not a viable option.
"I have personally attended one vehicle collision with a cattle beast that required the animal to be shot and have heard of other near misses," he said.
O'Shannessey said a collision between a car and a cattle beast would "write-off the car" and there was a "very high likelihood" the driver or passengers would be seriously injured "if not killed".
Federated Farmers president Bruce Wills was aware of the operation and said it was up to farmers to make sure fences were secure.
"Many of us are working next to main highways and there is no question that stock can be a hazard if they make it on to the roads.
"But sometimes things happen like a slip, a tree comes down on a fence or a gate is left open, providing opportunities for stock to get out."
Wills said losing stock can cost a farming business big dollars.
"But I haven't had a case like this across my desk for a number of years so I would say it was a rare event."
Federated Farmers Ruapehu representative Lyn Neeson said any killing of farm stock should be the "absolute last resort".
". . . and I feel for the farmer. Boundary fences must be maintained to a high standard and that includes boundary fences with all neighbours, the roading network and DOC."
Ruapehu District Council communications manager Paul Wheatcroft said staff had shot other cattle before Wednesday's operation.
"We had an incident where a cow was on the road and it was hit by a car."
He said the council hoped farmers would ensure stock were secured and that another multi-agency operation was not needed.