Brouk M, Belyea R
University of Missouri, Columbia 65211.
J Dairy Sci. 1993 Jan;76(1):175-82. doi: 10.3168/jds.S0022-0302(93)77336-1.
Nonlactating Guernsey cows were fed alfalfa silage or coarsely chopped, coarsely chopped and reconstituted, or long alfalfa hays. A computer system was developed to monitor chewing activity. Effects of diets upon chewing activity, digestibility, and ruminal parameters were determined. Digestibilities of DM and N were lower for silage than for hays. Cows fed silage had lower ruminal ammonia concentrations that were caused, at least in part, by greater bound N. Digestibilities of DM, N, and fiber were not different among the hays. The computer system recorded 98% of chews; visual measurements of chewing activity agreed well with computer-logged data. Cows spent more time (463 vs. 348 min/d) eating long alfalfa hay than silage; time spent ruminating, total chewing time, and chewing rates were not different among diets. During eating, cows fed hay had more chews per unit of DM or NDF than when eating silage; during rumination, diets had no effect. Eating time of cows fed alfalfa silage was less than for those fed alfalfa hay. Coarsely chopped alfalfa hay was as effective as long alfalfa hay in eliciting chewing activity.
非泌乳期的根西奶牛被喂食苜蓿青贮饲料或粗切、粗切并重新组合或长的苜蓿干草。开发了一个计算机系统来监测咀嚼活动。测定了日粮对咀嚼活动、消化率和瘤胃参数的影响。青贮饲料的干物质和氮的消化率低于干草。喂食青贮饲料的奶牛瘤胃氨浓度较低，这至少部分是由于结合态氮含量较高所致。干草之间的干物质、氮和纤维消化率没有差异。计算机系统记录了98%的咀嚼次数；咀嚼活动的视觉测量结果与计算机记录的数据非常吻合。奶牛吃长苜蓿干草比吃青贮饲料花费更多时间（463对348分钟/天）；日粮之间反刍时间、总咀嚼时间和咀嚼速率没有差异。在进食期间，喂食干草的奶牛每单位干物质或中性洗涤纤维的咀嚼次数比吃青贮饲料时多；在反刍期间，日粮没有影响。喂食苜蓿青贮饲料的奶牛进食时间比喂食苜蓿干草的奶牛短。粗切苜蓿干草在引发咀嚼活动方面与长苜蓿干草一样有效。
