In a fattening experiment with rapeseed meals produced by different techniques (cf. Part I) on broiler chickens, each experimental ration contained 10% of a variant rapeseed meal. The thyroid glands of the broiler chickens (allotted to 8 groups according to their diets) were examined for mass gain and submitted to various histopathological, biochemical and morphometric procedures. The variants of rapeseed meal applied to the animals in the groups IV, III and I have been found to be toxic. In contrast, the effects of the other variants of rapeseed meal on the morphology of the thyroid gland have been negligible.