Smuggling is a way of life for some people along the Border.
They are not mindless racketeers, but sophisticated, well resourced and well connected. Many of them own land and trade part-time in anything that will make money, be it cattle, sheep, pigs, animal feedstuff, animal drugs, legal or illegal. So there would be no animal smugglers if there were no farmers to buy their wares and sell them to factories. The Irish economy is in trouble because for nearly two years, since sterling strengthened steeply, sheep have been coming South from Northern Ireland for processing here. Some of this trade has been legitimate.