[P1-14] Effects of grain vinegar feeding on rumen fermentation parameters and passage rate in nonlactating Holstein cows
[Objective] To clarify effects of grain vinegar feeding on rumen fermentation and rumen passage rate in dairy cows for a better production, we conducted a preliminary experiment. [Methods] Ruminally cannulated non-lactating Holstein cows (n=6, 833±37 kg) were fed 6 kg barley grain and 2 kg grass hay with water, V1 (4.5% acetic acid) and V2 (15% acetic acid) in a duplicated 3×3 Latin square with 7 d period. Each period consists of 6 d adaptation and 1 d sampling. The target dose was set at 1 mol/d/head for both V1 (1.2 L) and V2 (0.4 L). The rumen fluid was sampled at 0 h, 1 h, 2 h, 3 h, 6 h, 12 h and 24 h after feeding. The ruminal pH, volatile fatty acid (VFA) and ammonia-N were analyzed. The rumen liquid pool size and passage rate were calculated using Co(II)-EDTA. Water intake was measured every morning then averaged. [Results] No significant differences were observed in ruminal pH, ammonia-N, total VFA and water intake. In this study, oral administration of grain vinegar did not affect rumen acetate concentration. Although rumen liquid pool size and passage rate were varied from 146 L (water) to 161 L (V1) and 6.83%/h (V1) to 7.14%/h (water), respectively, we did not find significance.