Journal of Comparative Physiology B

, Volume 162, Issue 6, pp 552–560 | Cite as

Digestive tract morphology and digestion in the wombats (Marsupialia: Vombatidae)

  • P. S. Barboza
  • I. D. Hume
Article

Summary

Wombats consume grasses and sedges which are often highly fibrous. The morphology of the digestive tract and the sequence of digestion were studied in two species of wombats from contrasting habitats: Vombatus ursinus from mesic habitats and Lasiorhinus latifrons from xeric regions. Studies were performed on wild wombats consuming their natural winter diets, and on captive wombats fed a high-fibre pelleted straw diet. Vombatus had a shorter digestive tract (9.2 vs 12.5 times body length) of greater capacity (wet contents 17.9 vs 13.7% body weight) than Lasiorhinus. The most capacious region of the digestive tract was the proximal colon (62–79% of contents). The proportional length and surface area of the proximal colon were greater in Vombatus, but those of the distal colon were greater in Lasiorhinus. These digestive morphologies may reflect adaptations for greater capacity and longer retention of digesta in Vombatus, but greater absorption and lower faecal water loss in Lasiorhinus. Apparent digestion along the digestive tract was estimated by reference to lignin. The proximal colon was the principal site of fibre and dry matter digestion, whereas nitrogen was mainly digested in the small intestine. Depot fats in captive wombats were highly unsaturated and reflected those in the diet. Therefore, lipids, proteins and soluble carbohydrates in the plant cell contents were digested and absorbed in the stomach and small intestine. Conversely, dietary fibre was probably retained and digested by microbial fermentation along the proximal colon.

Key words

Herbivore Hindgut Digestion Marsupial Wombat 

Abbreviations

ADF

acid detergent fibre

DM

dry matter

NDF

neutral detergent fibre

SD

standard deviation

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Argenzio RA (1988) Fluid and ion transport in the large intestine. In: Dobson A, Dobson MJ (eds) Aspects of digestive physiology in ruminants. Comstock, Ithaca, NY, pp 141–155Google Scholar
  2. Barboza PS (1989) Nutritional physiology of the Vombatidae. PhD thesis, University of New England, Armidale, NSW, AustraliaGoogle Scholar
  3. Barboza PS, Hume ID (1992) Hindgut fermentation in the wombats: two marsupial grazers. J Comp Physiol B 561–566Google Scholar
  4. Dellow DW, Hume ID (1982) Studies on the nutrition of macropodine marsupials. IV. Digestion in the stomach and intestine of Macropus giganteus, Thylogale thetis and Macropus eugenii. Aust J Zool 30: 767–777Google Scholar
  5. Dellow DW, Hume ID, Clarke RTJ, Bauchop T (1988) Microbial activity in the forestomach of free-living macropodid marsupials: comparisons with laboratory studies. Aust J Zool 36: 383–395Google Scholar
  6. Demment MW, Van Soest PJ (1985) A nutritional explanation for body-size patterns of ruminant and non-ruminant herbivores. Am Nat 125: 641–672Google Scholar
  7. Diamond J (1987) Adaptations of intestinal nutrient absorption in mammals. S Afr J Sci 83: 590–594Google Scholar
  8. Dierenfeld ES (1984) Diet quality of sympatric wombats kangaroos and rabbits during severe drought. PhD thesis, Cornell University, Ithaca, NY, USAGoogle Scholar
  9. Fahey JC Jr, Jung HG (1983) Lignin as a marker in digestion studies: a review. J Anim Sci 57: 220–225Google Scholar
  10. Goering HK, Van Soest PJ (1970) Forage fiber analyses (apparatus, reagents, procedures and some applications). (Agriculture handbook no 339), Agrieulture Research Service, US Department of Agriculture, Washington, DCGoogle Scholar
  11. Gupta SS, Hilditch TP (1951) The component acids and glycerides of a horse mesenteric fat. Biochem J 48: 137–146Google Scholar
  12. Hingson DJ, Milton GW (1968) The mucosa of the stomach of the wombat (Vombatus hirsutus) with special reference to the cardiogastric gland. Proc Linn Soc NSW 93: 69–75Google Scholar
  13. Hume ID (1989) Optimal digestive strategies in mammalian herbivores. Physiol Zool 62: 1145–1163Google Scholar
  14. Jung HC, Fahey GC Jr (1983) Nutritional implications of phenolic monomers and lignin: a review. J Anim Sci 57: 206–219Google Scholar
  15. Langer P (1988) The mammalian herbivore stomach. Fischer, Stuttgart, FRGGoogle Scholar
  16. Lehman P (1979) A Myoporum-Stipa community grazed by wombats — with particular reference to herbage production. MSc thesis, University of Adelaide, Adelaide, SA, AustraliaGoogle Scholar
  17. Lepage G, Roy CC (1986) Direct transesterification of all classes of lipids in a one-step reaction. J Lipid Res 27: 114–121Google Scholar
  18. Mackenzie WC (1918) The gastrointestinal tract in monotremes and marsupials. Critchley-Parker, Melbourne, AustraliaGoogle Scholar
  19. Mallett KJ, Cooke BD (1986) The ecology of the common wombat in South Australia. Nature Conservation Society of South Australia, Adelaide, AustraliaGoogle Scholar
  20. Mason VC (1984) Metabolism of nitrogenous compounds in the large gut. Proc Nutr Soc 43: 45–53Google Scholar
  21. McIlroy JC (1973) Aspects of the ecology of the common wombat, Vombatus ursinus (Shaw 1800). Unpublished PhD thesis, Australian National University, Canberra, ACT, AustraliaGoogle Scholar
  22. McIlroy JC (1976) Aspects of the ecology of the common wombat, Vombatus ursinus. I. Capture, handling, marking and radio-tracking techniques. Aust Wildlife Res 3: 105–116Google Scholar
  23. Sinclair AJ, O'Dea K (1987) The lipid levels and fatty acid compositions of the lean portions of pork, chicken and rabbit meats. Food Technol Aust 39: 232–233Google Scholar
  24. Stevens CE (1988) Comparative physiology of the vertebrate digestive system. Cambridge University Press, New YorkGoogle Scholar
  25. Van Soest PJ (1982) Nutritional ecology of the ruminant. O & B Books, Corvallis OR, USAGoogle Scholar
  26. Van Soest PJ, Robertson JB, Lewis BA (1991) Methods for dietary fibre, neutral detergent fiber and non-starch polysaccharides in relation to animal nutrition. J Dairy Sci 74: 3583–3597Google Scholar
  27. Wells RT (1973) Physiological and behavioural adaptations of the hairy-nosed wombat (Lasiorhinus latifrons Owen) to its arid environment. PhD thesis, University of Adelaide, Adelaide, SA, AustraliaGoogle Scholar
  28. Wells RT (1978) Field observations of the hairy-nosed wombat, Lasiorhinus latifrons (Owen). Aust Wildlife Res 5: 299–303Google Scholar
  29. Winer BJ (1971) Statistical principles in experimental design, 2nd edn. McCraw-Hill, New YorkGoogle Scholar
  30. Zar JH (1974) Biostatistical analysis. Prentice-Hall, SydneyGoogle Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • P. S. Barboza
    • 1
  • I. D. Hume
    • 1
  1. 1.Department of Biochemistry, Microbiology and NutritionUniversity of New EnglandArmidaleAustralia
  2. 2.Department of Zoological Research, National Zoological ParkSmithsonian InstitutionWashington, DCUSA
  3. 3.School of Biological Sciences A08University of SydneyAustralia

Personalised recommendations