Jørgensen H, Zhao X Q, Theil P K, Gabert V M, Bach Knudsen K E
Danish Institute of Agricultural Sciences, Department of Animal Nutrition and Physiology, Research Centre Foulum, Tjele, Denmark.
Arch Tierernahr. 2003 Apr;57(2):83-98. doi: 10.1080/0003942031000107280.
A study was performed to investigate the effect of different levels of dietary fibre (DF) and dietary protein on visceral organ size, digestibility, nitrogen balance and energy metabolism in rats. Thirty-six male Wistar rats, initial body weight about 76 g were used in a factorial design consisting of three levels of DF (low, 100 g/kg DM: medium, 250 g/kg DM and high, 290 g/kg DM) and two levels of dietary protein (low, 120 g/kg DM and high, 223 g/kg DM). The added fibre source was soybean hulls and Danish fish meal was used as sole source of dietary protein. Measurements of gas-exchange were done on six rats (one group) while urine and faeces were collected individually. The ratio of food/empty body gain increased (P<0.05) with increasing DF and decreasing levels of dietary protein. The weight of the digestive tract was larger (P<0.05) in rats fed the high fibre diet than in those fed the low fibre diet. The digestibility of nutrients and energy decreased linearly with increasing level of soybean fibre (P<0.05). An increased intake of DF was associated with a concomitant loss of protein and energy to faeces. The microbial degradation of NSP and other unabsorbed carbohydrates caused considerably changes in N metabolism of the colon. In rats fed the low protein diets increased levels of DF decreased N excretion in urine and increased N excretion in faeces, while the ratio of retained/digested protein remained constant. When rats were fed the high protein diet protein retention dropped in response to DF both absolute and relative to digested amount, indicating that energy intake could be a limiting factor. Heat production as a percentage of metabolizable energy (HP/ME) was higher (P<0.05) in rats fed the low protein diet than in rats fed the high protein diet, but no significant difference was found among DF levels.
进行了一项研究，以调查不同水平的膳食纤维（DF）和膳食蛋白质对大鼠内脏器官大小、消化率、氮平衡和能量代谢的影响。采用析因设计，选用36只初始体重约76 g的雄性Wistar大鼠，分为三个DF水平组（低，100 g/kg干物质；中，250 g/kg干物质；高，290 g/kg干物质）和两个膳食蛋白质水平组（低，120 g/kg干物质；高，223 g/kg干物质）。添加的纤维来源为大豆皮，丹麦鱼粉用作膳食蛋白质的唯一来源。对六只大鼠（一组）进行气体交换测量，同时分别收集尿液和粪便。食物/空体增重比随DF增加和膳食蛋白质水平降低而升高（P<0.05）。高纤维饮食组大鼠的消化道重量大于低纤维饮食组大鼠（P<0.05）。随着大豆纤维水平的升高，营养素和能量的消化率呈线性下降（P<0.05）。DF摄入量增加伴随着蛋白质和能量随粪便损失。非淀粉多糖（NSP）和其他未吸收碳水化合物的微生物降解导致结肠氮代谢发生显著变化。在低蛋白饮食组大鼠中，DF水平升高会降低尿液中的氮排泄，增加粪便中的氮排泄，而保留/消化蛋白质的比例保持不变。当大鼠饲喂高蛋白饮食时，DF会使蛋白质保留量绝对和相对于消化量均下降，表明能量摄入可能是一个限制因素。低蛋白饮食组大鼠的产热量占可代谢能量的百分比（HP/ME）高于高蛋白饮食组大鼠（P<0.05），但在不同DF水平之间未发现显著差异。
