Tafaj Myqerem, Maulbetsch Anja, Zebeli Qendrim, Steingass Herbert, Drochner Winfried
University of Hohenheim, Institute of Animal Nutrition, Stuttgart, Germany.
Arch Anim Nutr. 2005 Oct;59(5):313-24. doi: 10.1080/17450390500247840.
Four ruminally cannulated Holstein cows (BW 615 kg) in mid lactation were used to evaluate the effects of fibre level (39, 32, 28, 24 and 19% physically effective NDF [peNDF] in DM) in diets consisting of hay and slowly degradable concentrate on chewing activity, under a constant intake level (18 kg DM x d(-1)). The different dietary fibre concentrations were achieved by adjusting the hay to concentrate ratio. The above-mentioned levels of peNDF corresponded to 25, 40, 50, 60 and 70% concentrate respectively. The diets with decreasing share of concentrate were offered in sequence according to the progressive lactation of the cows. A decrease of the peNDF from 39-28% reduced total chewing and rumination time, total number of chews and number of boluses per day as well as chewing time spent per unit of DM. No significant change in chewing behaviour occurred between peNDF level of 28 and 24%. This peNDF level (i.e., 24%) might be considered as a tolerable fibre level. A further reduction of peNDF to 19% led to a significant reduction of chewing activity. This level can be considered as critical for chewing activity and presumably for the rumen health. The chewing parameters correlated linearly to fibre and non-fibre carbohydrates with R2 of 23-51%.
选用4头处于泌乳中期的安装有瘤胃瘘管的荷斯坦奶牛（体重615千克），在恒定采食量水平（18千克干物质/天）下，评估由干草和慢速降解精料组成的日粮中纤维水平（干物质中物理有效中性洗涤纤维[peNDF]分别为39%、32%、28%、24%和19%）对咀嚼活动的影响。通过调整干草与精料的比例来实现不同的膳食纤维浓度。上述peNDF水平分别对应25%、40%、50%、60%和70%的精料。随着奶牛泌乳进程的推进，依次提供精料比例逐渐降低的日粮。将peNDF从39%降至28%会使总咀嚼和反刍时间、每天的总咀嚼次数和食团数以及每单位干物质的咀嚼时间减少。在peNDF水平为28%和24%之间，咀嚼行为没有显著变化。这个peNDF水平（即24%）可被视为可耐受的纤维水平。将peNDF进一步降至19%会导致咀嚼活动显著减少。这个水平可被视为对咀嚼活动以及可能对瘤胃健康至关重要的水平。咀嚼参数与纤维和非纤维碳水化合物呈线性相关，决定系数R2为23% - 51%。
