In our experiment sows were grased during four grazing seasons, from April 28, 2000 to 23, August, 2001. The same number of indoor sows served as control animals. The results of the blood test show that, as a result of grazing, the beta carotene level of the blood serum has increased threefold. This difference disappeard after the farrow 30 days. On spring pasture, the grasingsows gained 50 kg in weight as opposed to 30 kg in the control animals. On the poor autumn pasture, the weight gained was only 30 kg, which was only 2 kg more in comparison with the performance of the control group. In the third grasing season the experiment sows weight gained was 13.7 kg and control group 37 kg. In the fourth season the control group weight gained was 4.4 kg more in comparison with the performance of the experiment sows. Grazing not very influence weight of gthe sows during the preast – feeding.