RESPONSE OF RATS AND CHICKS TO RAPESEED MEAL SUBJECTED TO DIFFERENT ENZYMATIC TREATMENTS

Abstract

Rapeseed meals (Brassica napus cv. Zephyr) were selectively prepared, either by autolysis, or treatment of meal from heated seed with mustard seed thioglucosidase, to yield products with relatively high content of nitriles or goitrin, respectively. These treated meals were incorporated into basal diets, replacing low-glucosinolate Bronowski meal on an equal weight basis, with all diets containing a total of 40% meal (14% protein). Diets were fed ad libitum to both rats and chicks. Weight gains of both rats and chicks were inversely related to the level of nitrile-rich meal in the diet. Rats were more severely affected than chicks. All rats receiving the diet containing 40% of nitrile-rich meal were dead within 7 days of receiving the diet, whereas 38% of the chicks fed comparable diets were alive after 15 days. Pale enlarged kidneys were associated in rats with the consumption of nitrile-rich diets. Both rats and chicks fed diets containing 40% of goitrin-rich meal gained weight, although the rate was less than that of the controls. Both species lost weight when fed diets containing 40% of a meal with active enzyme along with intact thioglucosides.