The experiment was carried out on 33 sows fed low energetic feeds ad libitum. Control sows (group I n = 3) were fed restricted with a standard mixture, while up to the 100^th day of pregnancy, the sows in groups II (n = 10) and III (n = 10) received ad libitum low energy diets containing a high amount of sugar beet pulp (50%), wheat bran (20%) and grass meal (10%). Animals in group III received the feed mixture for farrowed and nursing sows between days 28–56 of pregnancy. The reproductive parameters of groups II and III were similar to those of control animals, although daily feed intake during early pregnancy of these sows was higher by about 1 kg (40.6–42.2%, respectively for groups II and III), their energy intake in this period was higher by 15.8–27.9%, while during whole experimental period, only by 5.2–9.3% in comparison with control sows. The sow feeding system did not influence the number of piglets born and weaned or their rearing performance. The results of the experiment suggest that ad libitum feeding of sows using mixtures containing high amounts of dried sugar beet pulp, wheat bran and grass meal can be an alternative to the traditional system of feeding.