Police have carried out raids on a number of farms suspected of holding stolen livestock.
Officers from The Police Service of Northern Ireland (PSNI) and Gardai discovered 35 cows and 15 sheep at a farm in south Armagh, while 250 sheep were discovered on a nearby farm across the border.
A PSNI spokesman said more than 20 officers were involved in the searches.
While the teams did not find any clear evidence the animals had been stolen, they did retrieve a number of ear tags which did not belong to the herd.
They also found breaches of animal welfare and cattle documentation and investigations are continuing.
Insp Leslie Badger told the BBC: "It disrupts this type of activity - this is a big footprint into this area today in relation to the viability and the traceability of our animals - which end up on our tables.”