Clauss Marcus, Hofmann Reinold R, Streich W Jürgen, Fickel Jörns, Hummel Jürgen
Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland.
Oecologia. 2008 Sep;157(3):377-85. doi: 10.1007/s00442-008-1093-z. Epub 2008 Jul 9.
Using cranioskeletal measurements, several studies have generated evidence that grazing ruminants have a more pronounced mastication apparatus, in terms of muscle insertion areas and protuberances, than browsing ruminants, with the resulting hypothesis that grazers should have larger, heavier chewing muscles than browsers. However, the only investigation of this so far [Axmacher and Hofmann (J Zool 215:463-473, 1988)] did not find differences between ruminant feeding types in the masseter muscle mass of 22 species. Here, we expand the dataset to 48 ruminant species. Regardless of phylogenetic control in the statistical treatment, there was a significant positive correlation of body mass and masseter mass, and also a significant association between percent grass in the natural diet and masseter mass. The results support the concept that ruminant species that ingest more grass have relatively larger masseter muscles, possibly indicating an increased requirement to overcome the resistance of grass forage. The comparative chewing resistance of different forage classes may represent a rewarding field of ecophysiological research.
通过颅骨测量，多项研究已得出证据表明，就肌肉附着区域和突起而言，放牧反刍动物比啃食反刍动物拥有更发达的咀嚼器官，由此产生的假设是，放牧动物应比啃食动物拥有更大、更重的咀嚼肌。然而，迄今为止对此的唯一一项研究[Axmacher和Hofmann（《动物学杂志》215：463 - 473，1988年）]并未在22个物种的咬肌质量上发现反刍动物采食类型之间存在差异。在此，我们将数据集扩展至48个反刍动物物种。无论在统计处理中是否进行系统发育控制，体重与咬肌质量之间均存在显著的正相关，并且自然饮食中草的比例与咬肌质量之间也存在显著关联。结果支持了这样一种概念，即摄入更多草的反刍动物物种具有相对更大的咬肌，这可能表明克服草类饲料阻力的需求增加。不同饲料类别的比较咀嚼阻力可能代表了一个有益的生态生理学研究领域。
