Physical characteristics of gastrointestinal content of llama (Lama glama)

Abstract

Changes in digesta dry matter (DM) and mean digesta particle size (MPS) along the gastrointestinal tract are well known in ruminants, but not in camelids. We collected digesta from the dorsal (d) and ventral (v) first forestomach compartment (C1), the second forestomach compartment (C2), three proximal segments and the subsequent glandular part of the third compartment (C3A‐D), the caecum and the faeces twelve llamas (Lama glama). DM analysis indicates the presence of digesta stratification in the C1, the presence of fluid in the C2 to facilitate the sorting function of this compartment, the fluid‐absorbing function of the proximal parts of the C3, the secretion of enzymes and digestive acids in the C3D, and the water‐resorbing function of the lower intestinal tract. These findings illustrate the functional resemblance between the gastrointestinal tract of camelids and cattle‐like ruminants (C1 equivalent to the rumen with stratified contents, C2 to the reticulum, C3A/B/C to the omasum and C3D to the abomasum). MPS analysis revealed a progressive reduction in MPS from the C1 to the distal C3. This gradual transition is different from the clear‐cut threshold in ruminants between the reticulum and the omasum and had so far only been described in dromedaries (Camelus dromedarius). These findings indicate that regardless of the convergent property of rumination and resemblance of general mechanisms involved in contents stratification and particle sorting, differences between ruminants and camelids exist that could be interpreted as a more efficient functionality of the ruminant forestomach.

Teeth and the gastrointestinal tract in mammals: when 1 + 1 = 3

“…The forestomach sorting and washing mechanism is a convergent adaptation in camelids and ruminants, where different morphological structures fulfil similar physiological functions [114,133]. However, subtle differences in these morphologies exist, which particularly affect the size of the transitions between forestomach compartments; these are larger in ruminants [134], which is compatible with the finding that the forestomach system throughput, and hence food intake capacity, is higher in ruminants than in camelids [135].…”

“…In nonruminant foregut fermenters, a selective retention of large particles would not appear beneficial, given that these animals lack an option to efficiently reduce the size of these large particles. The selective particle passage and retention in ruminating mammals have also been demonstrated by analysing particle size at different sites in the digestive tract [108,109,112–114], or by the use of plastic markers of different size and density [115]. The latter also allow the demonstration that large particles are much more likely to be ruminated upon before leaving the forestomach than smaller particles [116].…”

Apparent diet digestibility of captive colobines in relation to stomach types with special reference to fibre digestion

“…In contrast to the detailed knowledge about the differential function of individual forestomach sections in ruminants and camelids [e.g. 46 ], there is, to date, no indication of the differential function of the forestomach compartments of non-ruminant foregut fermenters [ 47 ] beyond the provision of sheer fermentation chamber capacity, and this may well also apply to colobines.…”

Apparent diet digestibility of captive colobines in relation to stomach types with special reference to fibre digestion

“…In contrast to the detailed knowledge about the differential function of individual forestomach sections in ruminants and camelids [e.g. Clauss et al 38], there is, to date, no indication of the differential function of the forestomach compartments of non-ruminant foregut fermenters [39] beyond the provision of sheer fermentation chamber capacity, and this may well also apply to colobines.…”