The eating and rumination behaviour was investigated in sheep fed only corn silage diet (A, B or C) which was made in different year and the following results were obtained.
1) The time spent eating silage B was fairly long, but not significantly, as compared with that in silages A and C, and consequently, the eating rate with silage B was markedly slower than those with silages A and C. The rumination appearance (lag time after feeding) was fairly shorter with silage C than with silages A and B, but not significantly because there was a quite large variation between individuals.
2) Daily time spent ruminating tended to be longer after feeding silage C than after feeding of silage A or B. The daily number of rumination periods was slightly more with silage C than with silages A and B, and cyclic rate was clearly longer with silage C than with silages A and B.
3) In rumination efficiency, rumination index (time spent ruminating/100g D. M. eaten) was significantly high in silage A feeding as compared with those in feedings of silages B and C. Bolus time was clearly longer with silage C than those with silages A and B. The rumination chewing rate was significantly higher in feeding of silage A than in feedings of silages B and C. These findings obviously suggest that the quality of silages clearly influence the rumination behaviour, especially on rumination index and chewing rate during rumination.