The studies were carried out at the State Center of Pig Hybridization in Poland on the 40 young boars of the 990 synthetic line. The boars were fed on the same diet from 30 to 70 days of age. At 70 days, the boars were distributed into two groups (control and experimental). In each group there were 20 boars. The alocation to the groups was made with analogues method, i.e. from one litter one boar was asigned to a group. A feeding test was carried out from 70 to 180 days of age. During the feeding test the boars of the Control group were fed on standard diet, which contained 0.2 mg Se and 30 mg vitamin E per 1 kg. The Experimental group received 0.5 mg Se and 60 mg vitamin E per 1 kg of the ration. The participation of other components in both mixtures (control and experimental) was the same. The boars were housed in individual pens measuring 1x2 m, flooring was combination of solid concrete and slats (approximately 60:40). Water was provided for ad libitum and standarized feeding was applied. The daily feed ration was gradually increased along with the increasing body