Summary
A simulation model is used to quantify relationships between diet quality, digestive processes and body weight in ungulate herbivores. Retention time of food in the digestive tract is shown by regression to scale with W0.27, and to be longer in ruminants than in hindgut fermenters. Allometric relationships between whole gut mean retention time (MRT, h) and weight (W) were: MRT=9.4 W0.255 (r 2=0.80) for hindgut fermenters and MRT=15.3 W0.251 (r 2=0.76) in ruminants. Longer retention of ingesta by large-bodied ruminants and hindgut fermenters increases digestive efficiency relative to small animals and permits them to survive on lower-quality foods. Compared with ruminants, hindgut fermenters' faster throughput is an advantage which outweighs their lower digestive efficiency, particularly on poor quality foods, provided that food resources are not limiting. This suggests that the predominance of ruminants in the middle range of body weights results from their more efficient use of scarce resources under conditions of resource depletion. Considering only physical limitations on intake, the model shows that the allometric coefficient which scales energy intake to body mass is 0.88 in ruminants and 0.82 in hindgut fermenters. The advantages of large body size are countered by disadvantages where food quantity is limited, and we suggest that the upper limit to ungulate body size is determined by the ability to extract nutrients from feeding niches during the nadir of the seasonal cycle of resource quality and abundance.
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References
Allen MS, Mertens DR (1988) Evaluating constraints on fibre digestion by rumen microbes. J Nutr 118:261–270
Baker DL, Hobbs NT (1987) Strategies of digestion: digestive efficiency and retention time of foraging diets in mentane ungulates. Can J Zool 65:1978–1984
Blaxter KL (1971) Methods of measuring the energy metabolism of animals and interpretation of results obtained. Fed Proc 20:1436–1443
Bell RHV (1970) The use of the herb layer by grazing ungulates in the Serengeti. In: Watson A (ed) Animal population in relation to their food resources. Blackwell Scientific, New York, pp 111–123
Bell RHV (1971) A grazing system in the Serengeti. Sci Am 225:86–93
Clark AJ (1927) Comparative physiology of the heart. Cambridge University Press, Cambridge
Clemens ET, Maloiy GMO (1982) The digestive physiology of three East African herbivores: the elephant, rhinoceros and hippopotamus. J Zool 198:141–156
Demment MW and Van Soest PJ (1985) A nutritional explanation for body-size patterns of ruminant and nonruminant herbivores. Am Nat 125:641–672
Duncan P, Foose TJ, Gordon IJ, Gakahu CG, Lloyd M (1990) Comparative nutrient extraction from forages by grazing bovids and equids: a test of the nutritional model of equid/bovid competition and coexistence. Oecologia (Berlin) 84:411–418
Elsden SR, Hithcock MWS, Marshall RA, Phillipson AT (1946) Volatile acid in the digesta of ruminants and other animals. J Exp Biol 22:191–202
Fonnesbeck PV (1969) Partitioning the nutrients of forage for horses. J Anim Sci 28:624–633
Foose TM (1982) Trophic strategies of ruminant versus nonruminant ungulates. PhD Thesis, University of Chicago
Forbes JM (1980) A model of the short-term control of feeding in the ruminant: effects of changing animal or feed characteristics Appetite 1:21–41
Geist V (1974) On the relationship of ecology and behaviour in the evolution of ungulates: theoretical considerations. In: Geist V, Walther FR (eds) The behaviour of ungulates and its relation to management. IUCN Publications, New Series No 24 pp 235–246
Gordon IJ (1989) Vegetation community selection by ungulates on the Isle of Rhum. The food supply. J Appl Ecol 26:35–51
Grenet E, Martin-Rosset W, Chenost M (1984) Compared size and structure of plant particles in the horse and sheep faeces. Can J Anim Sci 64 (Suppl): 345–346
Gwynne MD, Bell RHV (1968) Selection of vegetation components by grazing ungulates in the Serengeti National Park. Nature (London) 220:390–393
Hansen RM, Mugambi MM, Bauni SM (1975) Diets and trophic ranking of ungulates of the northern Serengeti J Wildl Manage 49:823–829
Hintz AF (1969) Equine nutrition, comparisons of digestion coefficients obtained with cattle, sheep, rabbits and horses. Veterinarian 6:45–51
Hoppe PP, van Hoven W, von Engelhardt W, Prins RA, Lankhorst A, Gwynne MD (1983) Pregastric and caecal fermentation in dikdik (Madoqua kirki) and suni (Nesotragus moschatus). Comp Biochem Physiol 75A:517–524
Hoven W van, Boomker EA (1981) Feed utilization and digestion in the black wildebeest (Connochaetes gnou, Zimmerman, 1780) in the Golden Gate Highlands National Park. S Afr J Wildl Res 11:35–39
Illius AW, Gordon IJ (1987) The allometry of food intake in grazing ruminants. J Anim Ecol 56:989–999
Illius AW, Gordon IJ (1991) Prediction of intake and digestion in ruminants by a model of rumen kinetics integrating animal size and plant characteristics. J Agric Sci 116:145–157
Janis CM (1976) The evolutionary strategy of the Equidae and the origins of rumen and cecal digestion. Evolution 30:757–774
Janis CM (1989) A climatic explanation for patterns of evolutionary diversity in ungulate mammals. Palaeontology 32:463–481
Janis CM, Gordon IJ, Illius AW (1992) Modelling equid/ruminant competition: what happened to the North American browsing horses? Hist Biol (in press)
Jarman PJ (1974) The social organization of antelope in relation to their ecology. Behaviour 48:215–266
Johnson DE, Borman MM, Rittenhouse LR (1982) Intake, apparent utilization and rate of digestion in mares and cows. Proc West Sect Am Soc Anim Sci 33:3–5
Kinnear JE, Cockson A, Christensen P, Main AR (1979) The nutritional biology of the ruminants and ruminant-like mammals —a new approach. Comp Biochem Physiol 64A:357–365
Koller BL, Hintz HF, Robertson JB, Van Soest PJ (1978) Comparative cell wall and dry matter digestion in the cecum of the pony and the rumen of the cow using in vitro and nylon bag techniques. J Anim Sci 47:209–215
Maloiy GMO, Clemens ET, Kamau JMZ (1982) Aspects of digestion and in vivo rumen ferementation rate in six species of East African wild ruminants. J Zool 197:345–353
McNaughton SJ (1985) Ecology of a grazing ecosystem: the Serengeti. Ecol Monogr 55:259–294
Mertens DR (1977) Dietary fiber components: relationship to the rate and extent of ruminal digestion. Fed Proc 36:187–192
Peters RH (1983) The ecological implications of body size. Cambridge University Press, Cambridge
Owaga ML (1975) The feeding ecology of wildebeest and zebra in Athi-Kaputei plains. E Afr Wildl J 13:375–383
Owen-Smith RN (1988) Megaherbivores. The influence of very large body size on ecology. Cambridge Studies in Ecology. Cambridge University Press, Cambridge
Poppi DP, Minson DJ, Ternouth JH (1981) Studies of cattle and sheep eating leaf and stem fractions of grasses. III. The retention time in the rumen of large feed particles. Aust J Agric Res 32:123–137
Sinclair ARE, Gwynne MD (1972) Food selection and competition in the East African buffalo (Synceros caffer Sparrman). E Afr Wildl J 10:77–89
Smith LW, Goering HK, Gordon CH (1972) Relationships of forage compositions with rates of cell wall digestion and indigestibility of cell walls. J Dairy Sci 55:1140–1147
Taylor StCS (1980) Genetic size scaling rules in animal growth. Anim Prod 30:161–165
Uden P, Van Soest PJ (1984) Investigation of the in situ bag technique and a comparison of the fermentation in heifers, sheep, ponies and rabbits. J Anim Sci 58:213–221
Van Soest PJ (1982) Nutritional ecology of the ruminant. O & B Books Inc., Corvallis, Oregon
Van Soest PJ, Jeraci J, Foose T, Wrick K, Ehle F (1983) Comparative fermentation of fibre by man and other animals. Bull New Zealand Roy Soc 20:75–80
Warner ACI (1981) Rate of passage of digesta through the gut of mammals and birds. Nutr Abstr Rev Ser B 51:789–820
White RG, Holleman DF, Hubbert ME, Staland H (1987) Herbivores in cold climates. In: The nutrition of herbivores. Academic Press, London pp 465–486
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Illius, A.W., Gordon, I.J. Modelling the nutritional ecology of ungulate herbivores: evolution of body size and competitive interactions. Oecologia 89, 428–434 (1992). https://doi.org/10.1007/BF00317422
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DOI: https://doi.org/10.1007/BF00317422