title: Digesta kinetics in gazelles in comparison to other ruminants: Evidence for taxon-specific rumen fluid throughput to adjust digesta washing to the natural diet.
abstract: Digesta flow plays an important role in ruminant digestive physiology. We measured the mean retention time (MRT) of a solute and a particle marker in the gastrointestinal tract (GIT) and the reticulorumen (RR) of five gazelles and one dikdik species. Species-specific differences were independent from body mass (BM) or food intake. Comparative evaluations (including up to 31 other ruminant species) indicate that MRT GIT relate positively to BM, and are less related to feeding type (the percentage of grass in the natural diet, %grass) than MRT RR. The MRTparticleRR is related to BM and (as a trend) %grass, matching a higher RR capacity with increasing BM in grazers compared to browsers. MRTsoluteRR is neither linked to BM nor to %grass but shows a consistent phylogenetic signal. Selectivity factors (SF; MRTparticle/MRTsolute, proxies for the degree of digesta washing) are positively related to %grass, with a threshold effect, where species with >20% grass have higher SF. These findings suggest that in different ruminant taxa, morphophysiological adaptations controlling MRTsoluteRR evolved to achieve a similar SF RR in relation to a %grass threshold. A high SF could facilitate an increased microbial yield from the forestomach. Reasons for variation in SF above the %grass threshold might represent important drivers of ruminant diversification and await closer investigation.
authors: Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty Zurich, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland; ETH Zurich, Institute for Agricultural Sciences, Universitätstrasse 2, 8092 Zurich, Switzerland.
authors: Marie T
authors: MT
authors: Dittmann
authors: Institute of Animal Science, University of Bonn, Endenicher Alleee 15, 53115 Bonn, Germany.
authors: Jürgen
authors: J
authors: Hummel
authors: Al Wabra Wildlife Preservation (AWWP), Doha, Qatar.
authors: Sven
authors: S
authors: Hammer
authors: Al Wabra Wildlife Preservation (AWWP), Doha, Qatar.
authors: Abdi
authors: A
authors: Arif
authors: Al Wabra Wildlife Preservation (AWWP), Doha, Qatar.
authors: Christiana
authors: C
authors: Hebel
authors: Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty Zurich, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland.
authors: Dennis W H
authors: DW
authors: Müller
authors: Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty Zurich, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland.
authors: Julia
authors: J
authors: Fritz
authors: Institute of Animal Science, University of Bonn, Endenicher Alleee 15, 53115 Bonn, Germany.
authors: Patrick
authors: P
authors: Steuer
authors: ETH Zurich, Institute for Agricultural Sciences, Universitätstrasse 2, 8092 Zurich, Switzerland.
authors: Angela
authors: A
authors: Schwarm
authors: ETH Zurich, Institute for Agricultural Sciences, Universitätstrasse 2, 8092 Zurich, Switzerland.
authors: Michael
authors: M
authors: Kreuzer
authors: Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty Zurich, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland. Electronic address: m.clauss@vetclinics.uzh.ch.
authors: Marcus
authors: M
authors: Clauss
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D000866:Antelopes / Q000502:physiology*; D001835:Body Weight; D004032:Diet; D004063:Digestion; D004435:Eating; D041981:Gastrointestinal Tract / Q000502:physiology; D007700:Kinetics; D008297:Male; D010802:Phylogeny; D012417:Rumen / Q000502:physiology*; D013045:Species Specificity
keywords: Convergence; Diet; Gazella gazella; Gazella spekei; Gazella subgutturosa marica; Madoqua saltiana phillipsi; Nanger dama; Nanger soemmerringii; Passage