The influence of natural diet composition, food intake level, and body size on ingesta passage in primates

Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zürich, Switzerland.
Comparative biochemistry and physiology. Part A, Molecular & integrative physiology (Impact Factor: 2.37). 08/2008; 150(3):274-81. DOI: 10.1016/j.cbpa.2008.03.012
Source: PubMed

ABSTRACT An important component of digestive physiology involves ingesta mean retention time (MRT), which describes the time available for digestion. At least three different variables have been proposed to influence MRT in herbivorous mammals: body mass, diet type, and food intake (dry matter intake, DMI). To investigate which of these parameters influences MRT in primates, we collated data for 19 species from trials where both MRT and DMI were measured in captivity, and acquired data on the composition of the natural diet from the literature. We ran comparative tests using both raw species values and phylogenetically independent contrasts. MRT was not significantly associated with body mass, but there was a significant correlation between MRT and relative DMI (rDMI, g/kg(0.75)/d). MRT was also significantly correlated with diet type indices. Thus, both rDMI and diet type were better predictors of MRT than body mass. The rDMI-MRT relationship suggests that primate digestive differentiation occurs along a continuum between an "efficiency" (low intake, long MRT, high fiber digestibility) and an "intake" (high intake, short MRT, low fiber digestibility) strategy. Whereas simple-stomached (hindgut fermenting) species can be found along the whole continuum, foregut fermenters appear limited to the "efficiency" approach.

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Available from: Sylvia Ortmann, Aug 20, 2015
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    • "Of course, it could be argued that primates may simply alter the feeding rate, thereby increasing the energy return per unit time and thus compensating for the shortfall. This seems highly unlikely on theoretical grounds (Clauss et al., 2008) and has not been observed (or reported) in the wild. It is therefore considered here that a sedge-based diet may indeed be constrained by the time available for foraging, feeding, and digestion. "
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    Journal of Human Evolution 07/2015; in press. DOI:10.1016/j.jhevol.2015.06.009 · 3.87 Impact Factor
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    • "Unlike Hickey et al. (1999)'s prediction, the passage time of seeds were stable regardless of the amount of diet. Our result was different to those obtained for foregut herbivores (hippopotami and cattle) (Clauss et al. 2007), beavers (Fryxell et al. 1994) and primates (Clauss et al. 2007, 2008; Sawada et al. 2011), in which the passage time was shorter when the animals were fed larger amounts of fibrous foods, and similar to those of elephants and horses (Clauss et al. 2007), in which the passage time moderately increased when the animals consumed a larger amount of food. There are two possibilities that could explain why the passage time of our martens was stable. "
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    • "Among these is the one between MRT and digestibility, evident in vivo both intra-and interspecifically (Udén et al., 1982; Pearson et al., 2001; Munn and Dawson, 2006; Kim et al., 2007; Clauss et al., 2008, 2009, 2014b; Müller et al., 2013) and also in in vitro studies (Hummel et al., 2006), but notably also not always significant in other studies when phylogenetic relationships of the species investigated were taken into account (significant in PGLS in Clauss et al. (2009), but not in the larger and less homogenous dataset of Müller et al. (2013)). These discrepancies are at least partially due to the different proxies used for 'digestibility'. "
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    Comparative Biochemistry and Physiology - Part A Molecular & Integrative Physiology 10/2014; 179C:182-191. DOI:10.1016/j.cbpa.2014.10.006 · 2.37 Impact Factor
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