The Irish Farmers' Association has said gardaí and dog wardens should be given emergency powers to confiscate animals believed to be involved in sheep kills.

The Association says thousands of euro has been lost by farmers in the Midlands and West over Christmas because of attacks by unlicensed dogs.

It called on the Minister for Agriculture to allow gardaí to have the authority to move in and remove the animals for forensic testing.

Chairman of Roscommon IFA John O'Beirne also said the Government should consider raising the cost of a dog licence so that farmers could be compensated after sheep kills where the dogs are not insured.

Meanwhile, gardaí are investigating an attack on a flock of sheep in which 46 ewes were killed in Co Roscommon.

As many as seven dogs were involved in the attack on up to 95 ewes in lamb.

The attack happened on a farm near Castlerea last weekend.

A further seven sheep may still have to be put down due to the trauma of the attack.

IFA National Sheep Chairman James Murphy said he is taking calls on a frequent basis from sheep farmers around the country who have suffered similar attacks.

Mr Murphy said the latest series of attacks on sheep flocks must lead to dog owners taking greater responsibility.

He said that owners who do not have their dog under control at all times must realise they could be held responsible for such an attack, with serious consequences.

"Aside from the economic losses, for which dog owners can be held liable, the welfare implications for the flock can be very severe and long-lasting."

The IFA said that up to 2.5m lambs will be born on 30,000 sheep farms across the country over the next three months.

Separately, gardaí are investigating the theft of four heifers from a farm at Rockberry in Co Monaghan.

It is believed the animals, which are valued at €6,000, were stolen between 12am on 2 January and 9.30am on 3 January.

They were taken from a farm at Cordevlis, a few miles from Rockberry village.

Anyone with information is asked to contact Castleblayney Garda Station on 042 - 9740668.