Effects of Dietary Fibre on Digesta Passage, Nutrient Digestibility, and Gastrointestinal Tract Morphology in the Granivorous Mongolian Gerbil (Meriones unguiculatus)
Effects of Dietary Fibre on Digesta Passage, Nutrient Digestibility, and Gastrointestinal Tract Morphology in the Granivorous Mongolian Gerbil (Meriones unguiculatus)
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DOI：
10.1086/322928
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发表时间：
2001-09
影响因子：
1.6
通讯作者：
Yan-Xin Pei;Dehua Wang;I. Hume
中科院分区：
文献类型：
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作者：
Yan-Xin Pei;Dehua Wang;I. Hume
为了研究蒙古沙鼠（Meriones unguiculatus）的消化道性能，测量了饲喂低纤维或高纤维饮食的圈养动物的食物摄入量和消化率、食糜通过率和胃肠道形态。我们使用两种标记物（用于溶质的 Co-乙二胺四乙酸和用于颗粒的 Cr-媒染细胞壁）来测量消化物部分的差异通过率，以测试结肠分离机制 (CSM) 的存在。尽管高纤维饮食的干物质摄入量与低纤维饮食没有差异，但高纤维饮食的干物质、中性洗涤剂纤维、酸性洗涤剂纤维、粗蛋白和粗脂肪的消化率均显着较低。高纤维饮食的总能量摄入量也与低纤维饮食没有差异，但粪便中损失的能量比低纤维饮食高得多；因此，高纤维饮食的能量消化率和可消化能量摄入量显着较低。随着膳食纤维的增加，胃肠道各段的长度和干组织质量均趋于增大，但只有胃肠道总内容物、小肠内容物以及盲肠的长度和干组织质量显着增加。在低纤维饮食中，颗粒标记物的平均保留时间（MRT）显着大于溶质标记物，但在高纤维饮食中则不然；低纤维饮食的溶质/颗粒差异保留比为 0.62，高纤维饮食的溶质/颗粒差异保留比为 0.90。因此，没有证据表明两种饮食中溶质标记物有选择性保留。高纤维饮食中颗粒标记物的 MRT 明显较低，并且与溶质标记物的 MRT 方向相同。这些结果表明，食谷沙鼠没有 CSM，但可以调整其消化道容量以容纳更多的低质量食物。
To investigate digestive tract performance in Mongolian gerbils (Meriones unguiculatus), food intake and digestibility, digesta passage rate, and gastrointestinal tract morphology were measured in captive animals fed low‐ or high‐fibre diets. We used two markers (Co‐ethylene diamine tetra‐acetic acid for solutes and Cr‐mordanted cell walls for particles) to measure differential passage rates of digesta fractions in order to test for the presence of a colonic separation mechanism (CSM). Although dry‐matter intakes on the high‐fibre diet did not differ from those on the low‐fibre diet, digestibilities of dry matter, neutral‐detergent fibre, acid‐detergent fibre, crude protein, and crude fat were all significantly lower on the high‐fibre diet. Gross energy intake on the high‐fibre diet also did not differ from that on the low‐fibre diet, but energy lost in faeces was much higher than on the low‐fibre diet; thus, energy digestibility and digestible energy intake were significantly lower on the high‐fibre diet. The lengths and dry‐tissue masses of all segments of the gastrointestinal tract tended to enlarge in response to increased dietary fibre, but only the total tract contents, contents of the small intestine, and length and dry‐tissue mass of the caecum increased significantly. The mean retention time (MRT) of the particle marker was significantly greater than that of the solute marker on the low‐fibre but not the high‐fibre diet; the solute/particle differential retention ratio was 0.62 on the low‐fibre diet and 0.90 on the high‐fibre diet. Thus, there was no evidence for selective retention of the solute marker on either diet. The MRT of the particle marker was significantly lower on the high‐fibre diet and in the same direction as the MRT of the solute marker. These results suggest that the granivorous Mongolian gerbil has no CSM but can adjust its digestive tract capacity to accommodate greater quantities of low‐quality food.