Clemens E T, Stevens C E, Southworth M
J Nutr. 1975 Oct;105(10):1341-50. doi: 10.1093/jn/105.10.1341.
Sixteen geese were used to assess the movement of fluid and particulate digesta through their gastrointestinal tracts and to determine the diurnal variation in organic acid levels for the various segments of the tract. Fluid (polyethylene glycol and chronium-labeled ethylenediaminetetraacetic acid) and particulate markers (2 and 5 mm long) were administered with the meal. Animals were killed at given intervals after the administration of markers. The gastrointestinal tract was divided into nine segments for measurement of markers, pH, volatile fatty acids (VFA), and lactic acid contents. The data indicated a rapid evacuation of fluid marker from the foregut (crop, ventriculus, and proventriculus), while particulate markers were retained for extended periods of time. Retention of fluid marker was observed only within the cecum. Retrograde movement of particulate marker was demonstrated from the duodenum to ventriculus and proventriculus. Retrograde movement of fluid marker was observed from the cloaca to the colon, cecum, and distal third of the small intestine. However, particulate marker showed no retrograde movement in these segments of tract. Highest VFA levels were observed in the cecum. Retention of digesta and production of VFA within the colon were less than those noted for the dog, pig and pony. Lactic acid comprised less than 10% of the organic acids present in the gastrointestinal tract and were at their highest levels in the proximal and mid small intestine.
16只鹅被用于评估液体和颗粒性食糜在其胃肠道中的移动情况，并确定胃肠道各段有机酸水平的昼夜变化。液体（聚乙二醇和铬标记的乙二胺四乙酸）和颗粒性标记物（2毫米和5毫米长）与饲料一同投喂。在投喂标记物后的特定时间间隔处死动物。将胃肠道分为9段，用于测量标记物、pH值、挥发性脂肪酸（VFA）和乳酸含量。数据表明，液体标记物从前肠（嗉囊、肌胃和腺胃）快速排空，而颗粒性标记物则被长时间保留。仅在盲肠内观察到液体标记物的滞留。颗粒性标记物从十二指肠向肌胃和腺胃出现逆行移动。从泄殖腔到结肠、盲肠和小肠远端三分之一处观察到液体标记物的逆行移动。然而，颗粒性标记物在这些肠道段未出现逆行移动。盲肠中观察到最高的VFA水平。结肠内食糜的滞留和VFA的产生低于狗、猪和小马。乳酸占胃肠道中有机酸的比例不到10%，在小肠近端和中部含量最高。
