The effects of two main processing stages (cooking and toasting) in extraction plant on the nutritional value of double-low rapeseed products were studied. Raw seeds and cooked cake taken from the oil factory were defatted and compared with toasted rapeseed meal in N balance/growth performance experiment with rats and in growth performance experiment with brolier chickens. Moreover, the effect of temperature and time of heating in the laboratory (100 and 120°C for 10, 20 or 30 min) on protein value of defatted expeller cake was also studied in N balance/growth perfomance experiment with rats. The toasting process had the most depressing effect on the content of total and available lysine and of glucosinolates as compared to their level in the seeds. The rats and chickens fed with diet containing toasted rapeseed meal performed better than those fed with diets containing non-heated defatted rape seeds or cooked and defatted cake. The toasting process reduced harmful effect of rape seed on (P≤0.01) the thyroid and liver weights of rats and thyroid weight of chickens. Increasing temperature and time of laboratory heating resulted in linear decrease (P≤0.001) in lysine, available lysine and glucosinolate contents as well as protein value of defatted cake for rats (TD, BV and NPU). However, the decrease in lysine content was much more dependent on the increase of temperature than on the prolongation of heating. The performance of rats (body weight gain, feed utilization) was influenced (P≤0.01) by both factors. Feed intake and weight gain of rats decreasd as time of heating increased but only at higher temperature (120°C). The thyroid weight linearly deceased (P≤0.01) as temperature increased. It seems that toasting of double-low RSM in mild conditions is necessary to eliminate the negative infuence of residual glucosinolates on the animal performance.