Defatted meals of oilseeds play an important role as a protein resource in animal nutrition, but differ in their nutritional profiles. In our experiment, the effects of increasing the defatted rape seeds (DRS) rate in the diet of male Wistar Kyoto rats on the main hematological and biochemical parameters were evaluated. Twenty-four animals were randomly divided into four groups per six animals and fed by a semi-synthetic diet according to the experimental design for forty-seven (47) days. The experimental groups were: i) group DRS0 fed with the control diet; ii) group DRS30, where 30% of the soybean meal in the diet was replaced with DRS; iii) group DRS60, where 60% of the soybean meal in the diet was replaced with DRS; and iv) group DRS100, where 100% of the soybean meal in the diet was replaced with DRS. The comparison of the results showed no significant (P < 0.05) differences among the values of the animal weight, red blood and white blood pictures, and indicators of the potential hepatotoxicity. In the opposite, the increasing DRS rate in the diet resulted in a decrease of plasmatic cholesterol concentration as well as, an increase of specific activity of the selected antioxidative enzymes such as glutathione reductase (GR), glutathione S-transferase (GST), thioredoxin reductase (TrxR), and catalase (CAT) in the plasma.The experimental results indicated that DRS can be used as an appropriate substitution of soybean meal with no adverse effect on the animals’ health. Moreover, the results indicated positive health effects of the DRS leading to a decrease of cholesterol concentration and improvement of the antioxidative activity of the appropriate enzymes.

Key words: Rat, defatted rape seeds, hematological parameters, specific enzymatic activity.