Natural rapeseed oil contains erucic acid, which is mildly toxic to humans in large doses but is used as a food additive in smaller doses. Canola is one of many selected cultivars of rapeseed bred to have a low erucic acid content. Canola was developed in Canada and its name is a contraction of "Canadian oil, low acid". The name was also chosen partly for marketing reasons, so successfully that the name is sometimes mis-applied to other cultivars of rapeseed.
Processing of rapeseed for oil production provides rapeseed animal meal as a by-product. The by-product is a high-protein animal feed, competitive with soya. The feed is mostly employed for cattle feeding, but also for pigs and chickens (though less valuable for these). The meal has a very low content of the glucosinolates responsible for metabolism disruption in cattle and pigs.