Odd indeed, I assume Canada is like most of the western world in that you need to register your livestock’s birth with the state and tag/brand/chip them with identification. It would be difficult for another farm to abduct someone else’s livestock and pass off as their own
I don't know about Canada, but in the US, it wouldn't be hard. Getting a spot in line for the butcher might be though. First place I would look is the processors or auction houses. No one steals that many just to keep as pets and the longer you have to feed them, the less incentive there is to have stolen them in the first place. The other motivate is some peta type and is just going to release them to the wild.
Releasing to the wild is a terrible idea, cattle aren’t really capable of surviving in the wild anymore. So seems right up the alley of some PETA idiot’s brain yeah.
I suppose you could find an unscrupulous butcher who would slaughter all these unreported but if they ever got caught.. I wouldn’t consider it worth the risk if I was an abattoir owner