Earlier this month the US Department of Agriculture issued the final rule for US mandatory Country of Origin Labelling.

Dr Ron Plain, an agricultural economics professor with the University of Missouri, says most US packers and retailers are still deciding how to handle the issue once enforcement begins in April.

Dr Ron Plain-University of Missouri

My expectation on the hog side of it is we're probably going to see fewer hogs coming south into the United States and more pork.

In fact, if you take a look at recent trends, we seem to be trending up a little bit in hog slaughter in Canada.

I think when we look at the complications associated with record keeping and labelling and verifying the correct label, that lots of times it's going to end up more sensible and lower cost to slaughter hogs in Canada and send the pork south already labeled than it will be to send the hogs south.

The real challenge on labelling is at the packing plant where basically hogs are slaughtered one day and the pork is cut up and shipped out the next.

If your try to handle animals from more than one country on the same day, unless you're going to just label it all US and Canada, it becomes a real record keeping segregation challenge so a lot of plants are wanting to go with only one label and a number of them that had been killing just a small number of Canadian born pigs are deciding, we'll probably not be killing any once the full enforcement gets in place and I think it's going to put pressure on slaughtering more hogs in Canada and send the pork south.

Dr Plain observes some US retailers have decided to handle only one label while most packers prefer to go with a U.S. or a Canada-US label on all of the pork they produce and the trend has been more plants opting to kill US hogs only.