The aim of this paper was to measure the main aspects that characterize the rumination behavior in six months old calves fed using three different feed spaces allowance. During the experiments the following rumination behavior aspects were determined: number of rumination periods, the length of rumination periods and the total length of rumination periods. Results showed that calves spent ruminating, on average, only 96.4 minutes in the morning, 176 minutes in the afternoon and 262.6 minutes during the night when the length of feeding space was 0.6 m per calf. Calves spent ruminating 124.2 minutes during the morning, 173.6 minutes during the afternoon and 243.4 minutes during the night when the length of the feeding space was 0.32 m per calf. Calves spent ruminating 106.2 minutes during the morning, 134.2 minutes during the afternoon and 286.4 minutes during the night when the length of the feeding space was 0.28 m per calf. The total time spent ruminating by calves was 535 minutes when the length of feeding space was 0.6 m per calf, 541 minutes when the length of feeding space was 0.32 per calf and 527 minutes when the length of the feeding space was 0.28 per calf. There were no significant differences (p>0.05) for total time spent ruminating by calves between the three experimental variants.