Abstract
We compared forage digestion and passage rates among three groups of Nubian ibex (Capra ibex nubiana) — mature males, non-lactating females, and lactating females — to test hypotheses relating intraspecific digestive ability to body mass and reproduction costs. We hypothesized that large males (60 kg) would exhibit longer forage retention times and more complete digestion of fermentable cell walls than adult females (23 kg). We tested these predictions by measuring digestion and retention of a grass hay and an alfalfa hay, forages that exhibited contrasting rates and extents of cell wall digestion. Consistent with predictions, males retained both forages longer than non-lactating females. However, by substantially increasing gut fill, lactating females increased both intake and retention time with respect to non-lactating females. Contrary to predictions, all three groups digested the grass (66% digestible) and alfalfa hay (63%) equally well. Alfalfa cell wall was less digestible than that of grass hay (60% vs 69% digestible), and retention time of alfalfa was consistently, but not statistically significantly, shorter. Fiber digestion was not correlated with retention time, emphasizing the ability of behavioral processes to modify digestion rate. We postulate that females achieved their greater digestion rate by masticating forages much more thoroughly than males.
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References
Akin DE (1979) Microscopic evaluation of forage digestion by rumen microorganisms — a review. J Anim Sci 48: 701–710
Allen MS, Mertens DR (1988) Evaluating constraints on fiber digestion by rumen microbes. J Nutr 118: 261–270
Ammann AP, Cowan RL, Mothershead CL, Baumgardt BR (1973) Dry matter and energy intake in relation to digestibility in white-tailed deer. J Wildl Manage 37: 195–201
AOAC (1980) Official methods of analysis. Assoc Official Anal Chem, Washington, D.C.
Baker DL, Hobbs NT (1987) Strategies of digestion: digestive efficiency and retention time of forage diets in montane ungulates. Can J Zool 65: 1978–1984
Beier P (1987) Sex differences in quality of white-tailed deer diets. J Mammal 68: 323–329
Bjorndal KA, Bolten AB, Moore JE (1990) Digestive fermentation in herbivores: effect of food particle size. Physiol Zool 63: 710–721
Brooks J III, Urness PJ (1984) Comparison of in vivo and in vitro digestibility of forages by elk. J Anim Sci 58: 963–970
Choshniak I, Arnon H, Shkolnik A (1984) Digestive efficiency in a wild goat the Nubian ibex. Can J Anim Sci 64 [Suppl]: 160–162
Clutton-Brock TH, Guinness FE, Albon D (1982) Red deer: behavior and ecology of two sexes. University of Chicago Press, Chicago
Demment MW (1982) The scaling of ruminoreticulum size with body weight in East African ungulates. Afr J Ecol 20: 43–47
Demment MW (1983) Feeding ecology and the evolution of body size of baboons. Afr J Ecol 21: 219–233
Demment MW, Greenwood GB (1988) Forage ingestion: effects of sward characteristics and body size. J Anim Sci 66: 2380–2392
Demment MW, Van Soest PJ (1985) A nutritional explanation for body-size patterns of ruminant and nonruminant herbivores. Am Nat 125: 641–672
Domingue BMF, Dellow DW, Barry TN (1991a) The efficiency of chewing during eating and ruminating in goats and sheep. Br J Nutr 65: 355–363
Domingue BMF, Dellow DW, Barry TN (1991b) Voluntary intake and rumen digestion of a low-quality roughage by goats and sheep. J Agric Sci 117: 111–120
Dove H, Freer M (1979) The accuracy of tritiated water turnover rate as an estimate of milk intake in lambs. Aust J Agric Res 30: 725–739
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 84: 411–418
Fadel JG, Uden P, Robinson PH (1987) Effect of nitrogen and energy supplements on intake and digestion of oat straw by non-lactating dairy cows. J Agric Sci 109: 503–511
Faichney GJ (1975) The use of markers to partition digestion within the gastro-intestinal tract of ruminants. In: McDonald IW, Warner ACI (eds) Digestion and metabolism in the ruminant. University of New England Publication Unit, Armidale, N.S.W., Australia
Fell BF, Campbell RM, Mackie WS, Weekes TEC (1972) Changes associated with pregnancy and lactation in some extra-reproductive organs of the ewe. J Agric Sci 79: 397–407
Fortelius M (1985) Ungulate cheek teeth: developmental, functional, and evolutionary interrelations. Acta Zool Fenn 180: 1–76
Fryxell JM (1991) Forage quality and aggregation by large herbivores. Am Nat 138: 478–498
Goering HK, Van Soest PJ (1970) Forage fiber analyses. U S Dep Agric Res Serv Agric Handb 379: 1–20
Gordon IJ, Illius AW (1994) The functional significnce of the browser-grazer dichotomy in African ruminants. Oecologia 98: 167–175
Gross JE, Wang Z, Wunder BA (1985) Effects of food quality and energy needs: changes in gut morphology and capacity of Microtus ochrogaster. J Mammal 66: 661–667
Gross JE, Alkon PU, Demment MW (1995a) Grouping patterns and spatial segregation by Nubian ibex. J Arid Environ 30: 423–439
Gross JE, Demment MW, Alkon PU, Kotzman M (1995b) Feeding and chewing behaviours of Nubian ibex: compensation for sex-related differences in body size. Funct Ecol 9: 385–393
Hammond KA, Wunder BA (1991) The role of diet quality and energy need in the nutritional ecology of a small herbivore, Microtus ochrogaster. Physiol Zool 64: 541–567
Hartnell GF, Satter LD (1979) Determination of rumen fill, retention time and ruminal turnover rates of ingesta at different stages of lactation in dairy cows. J Anim Sci 48: 381–392
Hodgson J, Forbes TDA, Armstrong RH, Beattie MM, Hunter EA (1991) Comparative studies of the ingestive behaviour and herbage intake of sheep and cattle grazing indigenous hill plant communities. J Appl Ecol 28: 205–227
Hofmann RR (1982) Zyklische Umbauvorgänge am Verdauungsapparat des Gamswildes als Ausdruck evolutionärer Anpassung an extreme Lebensräume. Allg Forst Z 51/52: 1562–1564
Holleman DF, White RG (1989) Determination of digesta fill and passage rate from nonabsorbed particulate phase markers using the single dosing method. Can J Zool 67: 488–494
Huston JE, Rector BS, Ellis WC, Allen ML (1986) Dynamics of digestion in cattle, sheep, goats and deer. J Anim Sci 62: 208–215
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
Justice KE, Smith FA (1992) A model of dietary fiber utilization by small mammalian herbivores, with empirical results for Neotoma. Am Nat 139: 398–416
LaGory KE, Bagshaw III C, Brisbin Jr IL (1991) Niche differences between male and female white-tailed deer on Ossabaw Island, Georgia. Appl Anim Behav 29: 205–214
Macfarlane WV, Howard B, Siebert BD (1969) Tritiated water in the measurement of milk intake and tissue growth of ruminants in the field. Nature 221: 578–579
Maltz E, Shkolnik A (1984) Lactational strategies of desert ruminants: the Bedouin goat, ibex, and desert gazelle. Symp Zool Soc Lond 51: 193–213
Matis JH (1972) Gamma time-dependency in Blaxter's compartmental model. Biometrics 28: 597–602
McCullough DR, Hirth DH, Newhouse SJ (1989) Resource partitioning between sexes in white-tailed deer. J Wildl Manage 52: 277–283
Mertens DR (1973) Application of theoretical mathematical models to cell wall digestion and forage intake in ruminants. PhD thesis, Cornell University, Ithaca, New York
Mertens DR (1977) Dietary fibre components: relationship to the rate and extent of ruminal digestion. Fed Proc 36: 187–192
Miller BK, Litvaitis JA (1992) Habitat segregation by moose in a boreal forest ecotone. Acta Theriol 37: 41–50
Milne JA, MacRae JC, Spence AM, Wilson S (1978) A comparison of the voluntary intake and digestion of a range of forages at different times of the year by the sheep and red deer (Cervus elaphus). Br J Nutr 40: 347–357
Milton K (1979) Factors influencing leaf choice by howler monkeys: a test of some hypotheses of food selection by generalist herbivores. Am Nat 114: 362–378
Mitchell HH (1962) Comparative nutrition of man and domestic animals. Academic Press, New York
Montgomery MJ, Baumgardt BR (1965) Regulation of food intake in ruminants. I. Pelleted rations varying in energy concentration. J Dairy Sci 48: 569–574
Norvsis M J (1990) SPSS/PC+ Advanced statistics 4.0. SPSS, Chicago, Illinois
Palmer WL, Cowan RL, Ammann AP (1976) Effect of innoculum source on in vitro digestion of deer foods. J Wildl Manage 40: 301–307
Parra R (1978) Comparison of foregut and hindgut fermentation in herbivores. In: Montgomery GG (ed) The ecology of arboreal folivores. Smithsonian Institution Press, Washington, D.C., pp 209–229
Penry DL, Jumars PA (1987) Modeling animal guts as chemical reactors. Am Nat 129: 69–96
Poppi DP, Minson KJ, Ternouth JH (1981) Studies of cattle and sheep eating leaf and stem fractions of grasses. II. Factors controlling the retention of feed in the reticulo-rumen. Aust J Agric Res 32: 109–121
Reid CSW, Ulyatt MJ, Waghorn GC, Milligan LP (1979) Chewing and the physical breakdown of feed in sheep. Ann Rech Vet 10: 205–207
Robbins CT (1983) Wildlife feeding and nutrition. Academic Press, New York
Robbins CT, Van Soest PJ, Mautz WW, Moen AN (1975) Feed analysis and digestion with reference to white-tailed deer. J Wildl Manage 39: 67–79
SAS Institute Inc. (1988) SAS Institute, Cary, N.C.
Tyrrell HF, Moe PW (1975) Effect of intake on digestive efficiency. J Dairy Sci 58: 1151–1163
Uden P, Colucci PE, Van Soest PJ (1980) Investigation of chromium, cerium, and cobalt as markers in digesta: rate of passage studies. J Sci Food Agric 31: 625–632
Van Soest PJ (1994) Nutritional ecology of the ruminant. Cornell University Press, Ithaca, New York
Van Soest PJ, Fadel J, Sniffen CJ (1979) Discount factors for energy and protein in ruminant feeds. Proc Cornell Nutr Conf 1979: 63–75
Van Soest PJ, Foose T, Robertson JB (1983) Comparative digestive capacities of herbivores. Proc Cornell Nutr Conf 1983: 51–59
Weckerly FW (1993) Intersexual resource partitioning in blacktailed deer — a test of the body size hypothesis. J Wildl Manage 57: 475–494
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Gross, J.E., Alkon, P.U. & Demment, M.W. Nutritional ecology of dimorphic herbivores: digestion and passage rates in Nubian ibex. Oecologia 107, 170–178 (1996). https://doi.org/10.1007/BF00327900
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DOI: https://doi.org/10.1007/BF00327900