A Canadian study evaluated different levels of expeller canola meal in diets for weaned pigs. Levels tested were 0, 6, 12, 18 and 24 percent in diets fed for five weeks, starting one week after weaning (at 19 days of age). The expeller canola meal contained 34 percent crude protein, 17 percent oil and 11 micromol/gram glucosinolates (anti-nutritional factors).
Diets were based on wheat, whereas expeller canola meal replaced typical solvent-extracted soybean meal, on an iso-nutrient basis.
Results indicated that up to 18 percent inclusion level, expeller canola meal did not affect growth performance in young pigs. At 24 percent inclusion level, the intake of glucosinolates prevented piglets from consuming enough feed, as expected, from feeding high level of these anti-nutritional factors. Accepting the 18 percent inclusion level as a conservative figure, we can deduct that diets containing less than 2 micromol/g complete feed are safe for young pigs.
This number, presumably, can be used with other canola products, when formulation is based on glucosinolate levels. Even though an upper level based on daily intake of glucosinolates would be more accurate, this is impractical as it is impossible to predict with any degree of accuracy the feed intake of a given batch of piglets.