**2.2. Mechanography**

The ruminal contractions were analyzed using the electronic tensometric recorder PIT 212 (COMT, Bialystok, Poland). The analysis of mechanograms and calculations of results were performed similarly as in a case of electromyographic recording [32]. The number of the rumen motor activity was determined by the frequency on mechanograms, with 5 min intervals before and after the DD40.
