Alkaline heating of canola and rapeseed meals reduces toxicity for chicks

A simple method for improving the nutritive quality of canola and high glucosinolate rapeseed meals for monogastric animals (chicks) was developed; the meals were mixed with NaHCO3 and NH4HCO3, then heated in a conventional oven. Chicks fed untreated canola or rapeseed meals gained less weight than those fed a soybean meal diet, whereas chicks fed the alkaline-heated meals had weight gains not significantly different than those fed the soybean diet. The antithyroid effect of the untreated rapeseed meal was reduced by alkaline treatment of the meals, as shown by improved T4 and free T4 levels in chicks fed the processed products. In chicks fed untreated or alkaline-treated canola or alkaline heated rapeseed meal, all thyroid hormone levels were similar to those of birds fed the soybean meal diet. However, heart tissue of chicks fed diets containing rapeseed or canola meals showed muscle fiber degeneration, although relative heart weights were the same in all groups. Liver tissue from most of the chicks in all dietary groups appeared normal or only slightly abnormal. The nutritive value of both rapeseed and canola meals was improved by this simple processing technique.