Tahas S A, Martin Jurado O, Hammer S, Arif A, Reese S, Hatt J-M, Clauss M
Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, 8057, Zurich, Switzerland.
Al Wabra Wildlife Preservation, P.O. Box 44069, Doha, Qatar.
Anat Histol Embryol. 2017 Jun;46(3):282-293. doi: 10.1111/ahe.12268. Epub 2017 Mar 12.
Differences in macroscopic measurements of the gastrointestinal tract have been hypothesized to correlate with the browser-grazer continuum in the natural diet of ruminants. However, to what extent these characteristics represent species-specific traits, or respond to the actually ingested diet, remains to be investigated. Twelve surplus addax antelope (Addax nasomaculatus) were divided into two groups and fed, for 3 months, either their usual diet, consisting of a concentrate feed with a limited amount of hay, or a diet of unlimited hay only. After culling, macroscopic measurements were compared between groups. The macroscopic anatomy of the addax showed many characteristics considered typical for grazing or 'cattle-type' ruminants. While both diet groups had mesenteric, pericardial and perirenal adipose tissue, these depots were subjectively more pronounced in concentrate-fed animals. Hay-fed animals had significantly heavier filled forestomach compartments, with corresponding significantly longer linear measurements. Masseter muscles and the surface of first-order omasal leaves were significantly more prominent in hay-fed animals, reflecting possible adaptations to overcome resistance of grass forage and to reabsorb fluid from increased rumination, but differences were not as distinct as reported between 'cattle-type' and 'moose-type' ruminants. Some measurements such as reticular crests and empty foregut mass remained stable between groups, indicating possibly genetically pre-defined characteristics less prone to change in adult life. The results emphasize the adaptability of ruminant digestive tract anatomy in adult animals even after a short period of time, but also suggest limits to this adaptability that reveals a species-specific anatomy regardless of the diet actually consumed.
胃肠道宏观测量的差异被认为与反刍动物自然饮食中的食草-食叶连续体相关。然而，这些特征在多大程度上代表物种特异性特征，或对实际摄入的饮食做出反应，仍有待研究。将12只多余的旋角羚（Addax nasomaculatus）分为两组，分别喂食3个月，一组喂食其通常的饮食，即含有少量干草的浓缩饲料，另一组仅喂食无限量的干草。宰杀后，比较两组之间的宏观测量结果。旋角羚的宏观解剖显示出许多被认为是食草或“牛型”反刍动物典型的特征。虽然两组动物都有肠系膜、心包和肾周脂肪组织，但这些脂肪库在喂食浓缩饲料的动物中主观上更为明显。喂食干草的动物瘤胃前室充满时明显更重，相应的线性测量值也明显更长。喂食干草的动物咬肌和一级瓣胃叶表面明显更突出，这反映了可能的适应性变化，以克服草料的阻力，并从增加的反刍中重新吸收液体，但差异并不像“牛型”和“驼鹿型”反刍动物之间报道的那么明显。一些测量值，如网胃嵴和空腹前肠质量在两组之间保持稳定，表明可能是成年后不易改变的基因预先定义的特征。结果强调了成年动物反刍动物消化道解剖结构即使在短时间后也具有适应性，但也表明这种适应性存在局限性，即无论实际摄入何种饮食，都存在物种特异性解剖结构。
