Neal Armstrong, in his summary of technical interpretation 2015-0564611E5, writes as follows:
CRA now construes “livestock” more narrowly than as stated in IT-427R, so that it considers that raising rodents qualifies as farming only if they are sold as food rather than as pets.
Duly noted. But what about rodents that are raised as food for pets? I am not kidding: many mice and rats end up being sold as food for snakes (a practice I find troubling, by the way, given that rats, at least, are as intelligent as many breeds of dogs). The CRA, in the technical interpretation, says the following:
Regarding your particular situation, the raising or breeding of rodents could be considered “farming” for purposes of the Act if the primary purpose for such activity is to supply a food source, whether that food source is for animal consumption or human consumption. However, the raising or breeding of rodents or other animals to be sold for use as pets would not be considered as farming.