De Brabander D L, De Boever J L, De Smet A M, Vanacker J M, Boucqué C V
Department of Animal Nutrition and Husbandry, Agricultural Research Centre-Gent, Melle-Gontrode, Belgium.
J Dairy Sci. 1999 Jan;82(1):110-21. doi: 10.3168/jds.S0022-0302(99)75215-X.
The physical structure of fodder beets, raw potatoes, ensiled pressed sugar beet pulp, ensiled brewers grains, and corn cob silage was evaluated in diets containing concentrates and either corn silage or grass silage as the roughage source. In one series of experiments, the chewing activity of eight cows was measured over 4 d. The beet pulp and fodder beets were added to the two roughage sources at two ratios [20:80 and 35:65, dry matter (DM) basis]. Potatoes, brewers grains, and corn cob silage were fed in a fixed amount (5 to 6 kg of DM) with corn silage. The chewing indexes (eating and ruminating time per kilogram of DM ingested) for fodder beets and beet pulp averaged 34.3 and 32.3 min/kg of DM, respectively, and were hardly affected by the nature of the roughage or by the inclusion ratio. The chewing indexes for potatoes, brewers grains, and corn cob silage were 23.7, 56.6, and 41.6 min/kg of DM, respectively. In another series of experiments using 8 to 11 cows, the ratio of roughage to concentrates was lowered weekly by 5 percentage units, and the critical rough-age portion of the diet was determined (i.e., the amount just before a lack of physical structure was observed). The roughage source was either fed alone or supplemented with about 4 kg of DM of the experimental feed. The critical roughage portion of the diet decreased when the experimental feeds were added; the decrease was greatest with ensiled pressed beet pulp and was lowest with corn cob silage.
在含有精饲料且以玉米青贮或牧草青贮作为粗饲料来源的日粮中，对饲料甜菜、生马铃薯、青贮压榨甜菜粕、青贮啤酒糟和玉米青贮的物理结构进行了评估。在一系列实验中，对8头奶牛的咀嚼活动进行了为期4天的测量。甜菜粕和饲料甜菜以两种比例[干物质（DM）基础为20:80和35:65]添加到两种粗饲料来源中。马铃薯、啤酒糟和玉米青贮以固定量（5至6千克DM）与玉米青贮一起饲喂。饲料甜菜和甜菜粕的咀嚼指数（每摄入1千克DM的采食和反刍时间）分别平均为34.3和32.3分钟/千克DM，几乎不受粗饲料性质或添加比例的影响。马铃薯、啤酒糟和玉米青贮的咀嚼指数分别为23.7、56.6和41.6分钟/千克DM。在另一系列使用8至11头奶牛的实验中，粗饲料与精饲料的比例每周降低5个百分点，并确定日粮的临界粗饲料部分（即刚观察到缺乏物理结构之前的量）。粗饲料来源要么单独饲喂，要么补充约4千克DM的实验饲料。添加实验饲料后，日粮的临界粗饲料部分降低；青贮压榨甜菜粕的降低幅度最大，玉米青贮的降低幅度最小。
