ORCID Profile
0000-0003-3841-6207
Current Organisation
University of Zurich
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Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.CBPA.2015.09.021
Abstract: Methane (CH4) production varies between herbivore species, but reasons for this variation remain to be elucidated. Here, we report open-circuit chamber respiration measurements of CH4 production in four specimens each of two non-ruminant mammalian herbivores with a complex forestomach but largely differing in body size, the collared peccary (Pecari tajacu, mean body mass 17kg) and the pygmy hippopotamus (Hexaprotodon liberiensis, 229kg) fed lucerne-based diets. In addition, food intake, digestibility and mean retention times were measured in the same experiments. CH4 production averaged 8 and 72L/d, 18 and 19L/kg dry matter intake, and 4.0 and 4.2% of gross energy intake for the two species, respectively. When compared with previously reported data on CH4 production in other non-ruminant and ruminant foregut-fermenting as well as hindgut-fermenting species, it is evident that neither the question whether a species is a foregut fermenter or not, or whether it ruminates or not, is of the relevance previously suggested to explain variation in CH4 production between species. Rather, differences in CH4 production between species on similar diets appear related to species-specific differences in food intake and digesta retention kinetics.
Publisher: Springer Science and Business Media LLC
Date: 19-05-2016
Publisher: Wiley
Date: 30-06-2016
DOI: 10.1111/JPN.12356
Abstract: Sloths are renowned for their low metabolic rate, low food intake and low defecation frequency. We investigated factors of digestive physiology and energy metabolism in four captive in iduals (mean body mass 10.0 ± SD 3.7 kg) of a hitherto mostly unstudied sloth species, Linné's two-toed sloth (Choloepus didactylus), in a 2-week digestion recording and 23-h respiration experiment on animals fed a standard zoo diet of vegetables and starchy components. Dry matter intake, defecation frequency and particle mean retention time (MRT) in the gastrointestinal tract (GIT) were 12 ± 3 g/(kg(0.75) day), once every 5 days and >140 h in three in iduals, but 53 g/(kg(0.75) day), daily and 82 h in one in idual that was apparently compensating for a period of weight loss prior to the experiment. In all animals, solute marker was eliminated at a faster rate than the particle marker, indicating 'digesta washing' in the sloths' GIT. The overall metabolic rate calculated from oxygen consumption matched the metabolisable energy intake in three in iduals [173 ± 22 vs. 168 ± 44 kJ/(kg(0.75) day)] but not in the fourth one [225 vs. 698 kJ/(kg(0.75) day)], supporting the interpretation that this animal was replenishing body stores. In spite of the low food intake and the low-fibre diet (209 ± 26 g neutral detergent fibre/kg dry matter), methane production was rather high accounting for 9.4 ± 0.8% of gross energy intake (2.7% in the fourth in idual), which exceeded literature data for ruminants on forage-only diets. These results corroborate literature reports on low intake, low defecation frequency, low metabolic rate and long MRT in other sloth species. The long MRT is probably responsible for the comparatively high methane production, providing more opportunity for methanogenic archaea than in other non-ruminant mammals to produce significant amounts of methane.
Publisher: Elsevier BV
Date: 05-2016
Publisher: Wiley
Date: 24-04-2015
DOI: 10.1002/ZOO.21216
Abstract: Plains viscachas (Lagostomus maximus) are large South American, fossorial rodents susceptible to diabetic cataracts. Various aspects of their digestive physiology were studied in three different experiments with nine male and seven female adult animals and six different diets (total n of feeding trials = 35). Viscachas achieved mean retention times of 23–31 hr, which is of a magnitude also recorded in horses these did not differ for solute or small particle (<2 mm) markers. Secondary marker excretion peaks indicated coprophagy, and were rarer on high-protein as compared to grass hay-only diets. Mean resting metabolic rate was, at 229 kJ/kg0.75/day, lower than expected for a mammal of this size. Digestible energy requirement for maintenance was 445 kJ/kg0.75/day. At 1.6–2.7 L/day, viscachas produced more methane than expected for a hindgut fermenter of their size. On diets that included concentrate feeds, viscachas excreted glucose in their urine, corroborating reports on the susceptibility of this species for diabetes when kept on energy-dense food. Viscachas had a similar apparent digestibility of protein, lipids, and macrominerals as other rodents, rabbits, or domestic horses. This suggests that whether or not a species practices coprophagy does not have a major influence on these measures. Viscachas resemble other hindgut fermenters in their high apparent calcium digestibility. With respect to a digestibility-reducing effect of dietary fiber, viscachas differed from rabbits and guinea pigs but were similar to horses, suggesting that small body size needs not necessarily be linked to lower digestive efficiency on high-fiber diets.
Publisher: Canadian Science Publishing
Date: 10-2015
Abstract: Gut capacity is an important factor in digestive physiology and is often measured as dry matter fill (DMF) following dissection, which prevents repeated measures in the same animal. It was proposed to calculate DMF from food intake, digestibility, and gut mean retention time (MRT), but empirical tests of this are few. We calculated DMF from intake, digestibility, and the MRT of small-particle (1 mm) and large-particle (20 mm) markers in 20 sheep (Ovis aries L., 1758) fed at different intake levels and compared results with DMF at dissection at the end of the feeding trial. MRT for smaller particles was significantly shorter than for larger particles (34.4 ± 6.1 vs. 42.5 ± 7.6 h, respectively). Correspondingly, DMF calculated from smaller particles (0.98 ± 0.27 kg) was significantly lower than DMF calculated from larger particles (1.20 ± 0.30 kg). The latter was not significantly different from DMF measured at dissection (1.18 ± 0.34 kg). These results suggest that DMF can be estimated from measures of digestive physiology. The choice of particle marker to determine MRT is crucial for the accuracy of the proxy. In ruminants, where small particles are consistently eliminated faster than larger particles, considerations of marker particle size are particularly important.
Publisher: Springer Science and Business Media LLC
Date: 09-2017
Publisher: Springer International Publishing
Date: 2019
Publisher: The Company of Biologists
Date: 11-2015
DOI: 10.1242/JEB.128165
Abstract: Fundamental differences in methane (CH4) production between macropods (kangaroos) and ruminants have been suggested and linked to differences in the composition of the forestomach microbiome. Using six western grey kangaroos (Macropus fuliginosus) and four red kangaroos (Macropus rufus), we measured daily absolute CH4 production in vivo as well as CH4 yield (CH4 per unit of intake of dry matter, gross energy or digestible fibre) by open-circuit respirometry. Two food intake levels were tested using a chopped lucerne hay (alfalfa) diet. Body mass-specific absolute CH4 production resembled values previously reported in wallabies and non-ruminant herbivores such as horses, and did not differ with food intake level, although there was no concomitant proportionate decrease in fibre digestibility with higher food intake. In contrast, CH4 yield decreased with increasing intake, and was intermediate between values reported for ruminants and non-ruminant herbivores. These results correspond to those in ruminants and other non-ruminant species where increased intake (and hence a shorter digesta retention in the gut) leads to a lower CH4 yield. We hypothesize that rather than harbouring a fundamentally different microbiome in their foregut, the microbiome of macropods is in a particular metabolic state more tuned towards growth (i.e. biomass production) rather than CH4 production. This is due to the short digesta retention time in macropods and the known distinct ‘digesta washing’ in the gut of macropods, where fluids move faster than particles and hence most likely wash out microbes from the forestomach. Although our data suggest that kangaroos only produce about 27% of the body mass-specific volume of CH4 of ruminants, it remains to be modelled with species-specific growth rates and production conditions whether or not significantly lower CH4 amounts are emitted per kg of meat in kangaroo than in beef or mutton production.
Publisher: Wiley
Date: 09-01-2019
DOI: 10.1002/ZOO.21472
Abstract: The capybara (Hydrochoerus hydrochaeris), the largest living rodent, probably has a "mucus-trap" colonic separation mechanism. To test this hypothesis, we measured the mean retention time of a solute marker (MRT
Location: United Kingdom of Great Britain and Northern Ireland
Location: France
No related grants have been discovered for Marcus Clauss.