Abstarct :

Canola meal is of valuable feedstuffs which its production is increasing with invreasing  Canola culture. The feed was studied in nutrition of fattening beef for a period of 120 days.  Sixteen yearling growing male calves of Holstein,  weighing 267.69 ± 37. 97 kg. were used in a completely randomized design with 4 treatments ( diets ) and 4 replications. All the diets were fed three times a day as total mixed ration (TMR) including a ration of 60: 40 concentrate and forage. In the study,  canola meal was fed at four levels of zero,  5 ,  10  and  15  percent in the concentrate portion as treatments 1 to 4, respectively. Feed intake were weighed daily and bulls were weighed individually and monthly. Blood sampling was taken every 40 days for determination of T3 and T4 ,  well. By average, the diets contained  2.61 Mcal/kg of metabolizable energy and 14.33 percent of crude protein, in all groups. The result showed daily weight gains of 1300, 1329, 1231.3  and 1311.8 g. ,  dry matter intake of  9.12, 9.31, 9.08 and 9.18  kg. , feed conversion rate of  7.09, 7.06, 7.42 and 7.10 for treatments 1 - 4,  respectively.  Value of  148.25, 140.50, 153.00 and  142.00 ng/dl  determined for  T3 and were 8.00, 6.90, 6.98 and 5.75  µ g / dl determined, for  T4, respectively. It can be concluded that feeding Canola meal producted in the country ,  with low glucosinolates, is easily possible to use 15 percent of dry matter or 25 percent of  concentration of fattening young calves.