The intraruminal papillation gradient in wild ruminants of different feeding types: Implications for rumen physiology

Authors

  • Marcus Clauss,

    Corresponding author
    1. Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
    • Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Winterthurerstr. 260, 8057 Zurich, Switzerland
    Search for more papers by this author
  • Reinhold R. Hofmann,

    1. Research Group for Evolutionary Genetics, Leibniz-Institute for Zoo and Wildlife Research (IZW), Berlin, Germany
    Current affiliation:
    1. Trompeterhaus, 15837 Baruth/Mark, Germany
    Search for more papers by this author
  • Jörns Fickel,

    1. Research Group for Evolutionary Genetics, Leibniz-Institute for Zoo and Wildlife Research (IZW), Berlin, Germany
    Search for more papers by this author
  • W. Jürgen Streich,

    1. Research Group for Evolutionary Genetics, Leibniz-Institute for Zoo and Wildlife Research (IZW), Berlin, Germany
    Search for more papers by this author
  • Jürgen Hummel

    1. Department of Animal Nutrition, Institute of Animal Science, University of Bonn, Bonn, Germany
    Search for more papers by this author

Abstract

Browsing and grazing ruminants are thought to differ in the degree their rumen contents are stratified—which may be due to different characteristics of their respective forages, to particular adaptations of the animals, or both. However, this stratification is difficult to measure in live animals. The papillation of the rumen has been suggested as an anatomical proxy for stratification—with even papillation indicating homogenous contents, and uneven papillation (with few and small dorsal and ventral papillae, and prominent papillae in the atrium ruminis) stratified contents. Using the surface enlargement factor (SEF, indicating how basal mucosa surface is increased by papillae) of over 55 ruminant species, we demonstrate that differences between the SEFdorsal or SEFventral and the SEFatrium are significantly related to the percentage of grass in the natural diet. The more a species is adapted to grass, the more distinct this difference, with extreme grazers having unpapillated dorsal and ventral mucosa. The relative SEFdorsal as anatomical proxy for stratification, and the difference in particle and fluid retention in the rumen as physiological proxy for stratification, are highly correlated in species (n = 9) for which both kind of data are available. The results support the concept that the stratification of rumen contents varies among ruminants, with more homogenous contents in the more browsing and more stratified contents in the more grazing species. J. Morphol., 2009. © 2009 Wiley-Liss, Inc.

Ancillary