Faecal particle size distribution in captive wild ruminants: an approach to the browser/grazer dichotomy from the other end

Abstract

We investigated the particle size distribution in 245 faecal samples of 81 species of captive ruminants by a wet-sieving procedure. As a comparative measure, the modulus of fineness (MOF; Poppi et al. 1980) was used. Species were classified as frugivores (n=5), browsers (BR, n=16), intermediate feeders (IM, n=35) and grazers (GR, n=25). BR generally had a higher proportion of large particles, i.e. higher MOF values, than IM or GR of comparable size. These findings are in accord with reported lower fibre digestibility and less selective particle retention in BR, and are indicative of a difference in reticulo-ruminal physiology between the main ruminant feeding types. Possible consequences of the escape of larger particles from a browser's reticulo-rumen for the feeding of captive BR are briefly discussed.

Comment on “DNA from Pre-Clovis Human Coprolites in Oregon, North America”

“…Its external morphology resembled that of herbivore dung pellets, including the typical stained outer surface (4,5). Internally, the coarse character of the plant fibers, as observed in reference thin sections of herbivore dung (e.g., camel, cattle, goat, mouflon sheep, and sheep) and as reported from the dung of browsers (6,7), is also consistent with that of herbivores. The FTIR analysis shows the presence of silicates (in the 450 to 1100 cm -1 region) and organic material (in the 1300 to 4000 cm -1 region), which are compatible with decayed organic compounds; no minerogenic phosphate was noted (Fig.…”

Nutritional content of savanna plant foods: implications for browser/grazer models of ungulate diversification

“…One possible explanation for the apparent contradiction here is that fiber digestibility and overall nutritional quality of the diet may not be the primary determinant for achieving differential retention times. Alternative hypotheses for the evolution of longer rumen retention in grazers were put forward based on differences in particle sizes into which browse and grass are broken down in the digestive tract, differences in fluid dissociation between these food types, and perhaps most importantly, grass stratification and formation of a fibrous raft in the rumen (Owen-Smith 1982;Clauss and LechnerDoll 2001;Clauss et al 2002Clauss et al , 2003Clauss et al , 2006. Thus, if at all, differences in physical, rather than biochemical, properties of grass and browse may have provided the basis for diversification of ungulate feeding styles and associated stomach physiology (see Clauss et al 2003).…”

Old World Ruminant Morphophysiology, Life History, and Fossil Record: Exploring Key Innovations of a Diversification Sequence

“…However, it could be shown that the efficiency of the sorting mechanism does not differ in a relevant way between 'moose-type' ruminants with a low, and 'cattle-type' ruminants with a high, fluid throughput (Lechner et al 2010). Correspondingly, tragulids, whose fluid passage pattern in the forestomach matches that of 'moose-type' ruminants (Darlis et al 2012), do not stand out among ruminants in terms of faecal particle size reduction (Clauss et al 2002). But, the important additional advantage of a high fluid throughput through the forestomach could lie in the additional harvest of microbes that are washed out at a high rate , Clauss et al 2010a, Müller et al 2011b.…”