Oecologia

, Volume 78, Issue 4, pp 443–457 | Cite as

Evolutionary steps of ecophysiological adaptation and diversification of ruminants: a comparative view of their digestive system

  • R. R. Hofmann
Original Papers

Summary

A review is made of the ruminant digestive system in its morphophysiological variations and adaptations relating to foraging behaviour, digestive physiology, to interactions between plants and ruminants and to geographic and climatic diversity of ruminants' ecological niches. Evidence is provided for evolutionary trends from an extreme selectivity mainly for plant cell contents and dependence upon a fractionated fore- and hindgut fermentation, to an unselective intake of bulk roughage subjected to an efficient plant cell wall fermentation, mainly in the forestomachs. The review is based on detailed comparative morphological studies of all portions of the digestive system of 65 ruminant species from four continents. Their results are related to physiological evidence and to the classification of all extant ruminants into a flexible system of three overlapping morphophysiological feeding types: concentrate selectors (40%), grass and roughage eaters (25%) and intermediate, opportunistic, mixed feeders (35%). Several examples are discussed how ruminants of different feeding types are gaining ecological advantage and it is concluded that ruminants have achieved high levels of digestive efficiency at each evolutionary stage, (including well-documented seasonal adaptations of the digestive system) and that ruminant evolution is still going on. Deductions made from the few domesticated ruminant species may have, in the past, biased scientific evaluation of the free-ranging species' ecology. The main threat to a continuous ruminant evolution and diversity appears to be man's neglect for essential ecological interactions between wild ruminants and their specific habitats, which he alters or destroys.

Key words

Wild ruminants Digestive system Morphophysiological adaptation Evolutionary trends Plant-herbivore interactions 

Abbreviations

bw

body weight

CS

concentrate selector

DFC

distal fermentation chamber (distended caecocolon)

GR

grass and roughage eater

IM

intermediate (mixed) feeder

PFC

proximal fermentation chamber (ruminoreticulum/forestomachs)

RR

Ruminoreticulum

SCFA

Short-chain fatty acis (acetic, butyric, propionic acid set free by rumen bacteriae)

SE

Surface enlargement (of absorptive mucosa)

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Axmacher H (1987) Vergleichend-histologische und morphometrische Untersuchungen am Abomasum von 36 Wiederkäuer-Arten (Ruminantia Scopoli 1977). Med vet Diss Univ Giessen (Doctor thesis)Google Scholar
  2. Cooper SM, Owen-Smith N (1985) Condensed tannins deter feeding by browsing ruminants in a South African savanna. Oecologia 67:142–146Google Scholar
  3. Crompton AW (1987) Interoral food transport and manipulation. In: Bergman EN, Dobson A, Elliot JM (eds) Comparative aspects of Physiology of Digestion in Ruminants. Cornell Univ PressGoogle Scholar
  4. Engelhardt W von, Dellow DW, Hoeller H (1985) The potential of ruminants for the utilization of fibrous low-quality diets. Proc Nutr Soc 44:37–43Google Scholar
  5. Gould SJ (1986) Evolution and the triumph of homology, or why history matters. Am Sci 74:60–69Google Scholar
  6. Hofmann RR (1968) Comparisons of rumen and omasum structure in east african game ruminants in relation to their feeding habits. Symposium Zoological Society of London, No. 21; Comparative Nutrition of Wild Animals, Crawford MA (ed) London, pp 179–194Google Scholar
  7. Hofmann RR (1969) Zur Topographie und Morphologie des Wiederkäuermagens im Hinblick auf seine Funktion (nach vergleichenden Untersuchungen an Material ostafrikanischer Wildarten). Zentralbl Vet Med, Beiheft 10, pp 1–180Google Scholar
  8. Hofmann RR (1973) The ruminant stomach (stomach structure and feeding habits of East African game ruminants). Vol 2 East Afr Monogr Biol, E.A. Lit. Bureau, Nairobi, pp 1–364Google Scholar
  9. Hofmann RR (1982) Zyklische Umbauvorgänge am Verdauungsapparat des Gamswildes (Rupicapra rupicapra L. 1758) als Ausdruck evolutionärer Anpassung an extreme Lebensäume. Allg Forst Z 37:1562–1564Google Scholar
  10. Hofmann RR (1984) Feeding habits of mouflon (Ovis ammon musimon) and chamois (Rupicapra rupicapra) in relation to the morphophysiological adaptation of their digestive tract. Hoefs M (ed) Whitehorse Conf Wild Sheep and Goats, pp 341–355Google Scholar
  11. Hofmann RR (1985) Digestive physiology of the deer — their morphophysiological specialisation and adaptation. In: Drew K, Fennessy P (eds) Biology of Deer Production. Roy Soc New Zeal Bull 22:393–407Google Scholar
  12. Hofmann RR (1988) Morphophysiological evolutionary adaptations of the ruminant digestive system. In: Dobson A (ed) Comparative Aspects of Physiology of Digestion in Ruminants. Cornell Univ Press, pp 1–20Google Scholar
  13. Hofmann RR, Stewart DRM (1972) Grazer or Browser: a classification based on the stomach structure and feeding habits of East African ruminants. Mammalia, Paris 36:226–240Google Scholar
  14. Hofmann RR, Schwartz HJ, Schwartz M (1987) Morphological adaptation of the forestomach of small East African goats to seasonal changes of forage quality. Proc. IV Internat Conference on Goats, Brasilia, Vol. II, No. 97: p 1369 EMBRAPA-DDT (Abstract)Google Scholar
  15. Hoppe PP, Hoven W van, Engelhardt W von, Prins RA, Lankhurst A, Gwynne MD (1983) Pregastric and caecal fermentation in dikdik (Madoqua kirki) and suni (Nesotragus moschatus). Comp Biochem Physiol 75A:517–524Google Scholar
  16. Hungate RE (1985) Symbosis between gut microbes and animals. In: Taylor TG, Jenkins NK (eds) Proceed. XIII Internat Congress of Nutrition. John Libbey, London/Paris, pp 211–214Google Scholar
  17. Janis CH (1976) The evolutionary strategy of the Equidae and the origins of rumen and caecal digestion. Evolution 30:757–776Google Scholar
  18. Janis CH (1986) An estimation of tooth volume and hypsodonty, indices in ungulate mammals and the correlation of these factors with dietary preference. Proceed. VII Internat Symposium on Dental Morphology, ParisGoogle Scholar
  19. Kay RNB (1985) Comparative studies of food propulsion in ruminants. In: Ooms LA, Degryse AD, Marsboom R (eds) The ruminant stomach. Proceed Int Workshop Antwerpen, vol 1:159–173Google Scholar
  20. Kay RNB (1987) Weights of salivary glands in ruminant animals. J Zool Lond 211:431–436Google Scholar
  21. Langer P (1988) The mammalian herbivore stomach. Comparative anatomy, function and evolution. G Fischer, Stuttgart New YorkGoogle Scholar
  22. Ludwig J (1986) Vergleichend-histologische und morphometrische Untersuchungen am Dickdarm von 30 Wiederkäuer-Arten (Ruminantia SCOPOLI 1977). Vet Med Diss (Doctor thesis) Univ Giessen, pp 1–160Google Scholar
  23. Nygren K, Hofmann RR (1988) Seasonal variations of food particle size in moose (in press)Google Scholar
  24. Ørskov ER, Benzie D, Kay RNB (1970) British J Nutr 24:785–795Google Scholar
  25. Ørskov ER (1986) Future perspectives for the protection of nutrients from fermentation in the rumen. EUR 10054, Neimann-Sørensen A (ed) ECC Agricultural series, pp 217–226Google Scholar
  26. Owen-Smith N (1985) Niche separation among African ungulates. In: Vrba ES (ed) Species and speciation. Transvaal Museum Monograph No. 4:167–171Google Scholar
  27. Prins RA, Lankhurst A, Hoven W van (1984) Gastrointestinal fermentation in herbivores and the extent of plant cell-wall digestion. In: Gilchrist FMC, Mackie RI (eds) Herbivore Nutrition in the Subtropics and Tropics. Science Press, Johannesburg, pp 408–434Google Scholar
  28. Provenza FD, Malechek JC (1984) Diet selection by domestic goats in relation to the blackbrush twig chemistry. J Appl Ecol 21:831–841Google Scholar
  29. Renecker LA (1985) Quality of forage used by moose. In: Annual Report, Wildlife Prod & Mgmt Programme, Dept Animal Science. Univ Alberta, pp 19–20cGoogle Scholar
  30. Schmuck U (1985) Die Zunge der Wiederkäuer (vergleichend-anatomische und histologische Untersuchungen an 42 Haus- und Wildwiederkäuer-Arten, Ruminantia SCOPOLI 1977). Vet Med Diss (Doctor thesis) Univ Giessen 1–120Google Scholar
  31. Schwartz HJ, Engelhardt W von, Said AN, Hofmann RR, Schultka W, Rutagwenda T, Carles AB (1987) Adaptive strategies to seasonal changes of forage supply of the small east african goat in comparison to the somali balckhead sheep. Proc IV Int Conference on Goats, Brasilia (March 1987)Google Scholar
  32. Stöckmann W (1979) Differences in the shape of the mandibles of African Bovidae (Mammalia) in relation to food composition. Zool Jahrb Syst 106:344–373Google Scholar
  33. Sutton JD (1986) Ruman fermentation and gastro-intestinal absorption: carbohydrates. EUR 10054, Neimann-Sørensen A (ed) EEC Agricultural series, pp 21–38Google Scholar
  34. Taylor CR, Weibel ER (1981) Design of the Mammalian Respiratory System. I. Problem and Strategy. Resp Physiol 44:1–10Google Scholar
  35. Ulyatt MJ, Dellow DW, Reid CSW, Bauchop T (1975) Structure and function of the large intestine of ruminants. In: Digestion and Metabolism in the Ruminant, McDonald IW, Warner ACI (eds) Univ New England Publishing Unit, Armidale, pp 119–133Google Scholar
  36. Van Soest PJ (1982) Nutritional Ecology of the Ruminant, OB Books, Corvallis, pp 1–373Google Scholar

Copyright information

© Springer-Verlag 1989

Authors and Affiliations

  • R. R. Hofmann
    • 1
  1. 1.Institut für Veterinär-Anatomie,-Histologie und-Embryologie, Abteilung Vergleichende Anatomie der Haus- und WildtiereJustus-Liebig-Universität GiessenGiessenFederal Republic of Germany

Personalised recommendations