Brunsgaard G, Bach Knudsen K E, Eggum B O
National Institute of Animal Science, Department of Animal Physiology and Biochemistry, Research Centre Foulum, Tjele, Denmark.
Br J Nutr. 1995 Dec;74(6):833-48.
In balanced experiments with rats the influence of the period of adaptation on nutrient digestibility in diets containing cellulose (CEL), guar gum (GG), pectin (PEC) or retrograded high amylose maize starch (RS) was studied. Inclusion level was 80 g/kg diet DM except for the retrograded high-amylose maize starch, where the level was 316 g/kg diet DM. A diet containing normal maize starch only acted as a control diet (FF). The apparent digestibilities of DM, NSP, starch and protein were determined after adaptation periods of 4 d and 2, 4, 6 and 8 weeks. The digestibility of nutrients was affected by diet (P < 0.001) as well as by the period of adaptation (P < 0.001). The digestibilities of DM, NSP and starch increased asymptotically during the course of the experiment. The asymptotic progress over time was most pronounced for the GG, PEC and RS diets. The estimated periods of adaptation required for stable DM digestibility were approximately 1 week for the GG, PEC and RS diets and < 4 d for the FF and CEL diets. The digestibility of NSP in the GG and PEC diets was also stable after approximately 1 week, while it was stable from < 4 d for the CEL diet. However, PEC increased the faecal content of uronic acids for at least 2 weeks. A stable starch digestibility required 1 month in the case of RS and 3-10 d for the other diets. The high faecal content of glucose for the RS diet decreased during all 8 weeks but was still high at the close of the experiment. The apparent protein digestibility changed over time in a parabolic rather than an asymptotic fashion. The GG, PEC and RS diets increased the amount of N excreted by the faecal route.
在大鼠的平衡实验中,研究了适应期对含纤维素(CEL)、瓜尔豆胶(GG)、果胶(PEC)或回生高直链玉米淀粉(RS)日粮中养分消化率的影响。除回生高直链玉米淀粉的添加水平为316 g/kg日粮干物质外,其他日粮的添加水平均为80 g/kg日粮干物质。仅含普通玉米淀粉的日粮作为对照日粮(FF)。在4天以及2、4、6和8周的适应期后,测定了干物质、非淀粉多糖、淀粉和蛋白质的表观消化率。养分消化率受日粮(P<0.001)以及适应期(P<0.001)的影响。在实验过程中,干物质、非淀粉多糖和淀粉的消化率呈渐近增加。GG、PEC和RS日粮随时间的渐近进展最为明显。GG、PEC和RS日粮达到稳定干物质消化率所需的估计适应期约为1周,FF和CEL日粮则<4天。GG和PEC日粮中非淀粉多糖的消化率在约1周后也趋于稳定,而CEL日粮在<4天后就稳定了。然而,PEC使糖醛酸的粪便含量至少在2周内增加。RS日粮达到稳定淀粉消化率需要1个月,其他日粮则需要3 - 10天。RS日粮粪便中葡萄糖含量在整个8周内均下降,但在实验结束时仍较高。表观蛋白质消化率随时间呈抛物线而非渐近方式变化。GG、PEC和RS日粮增加了粪便氮排泄量。