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Marcus Clauss - One of the best experts on this subject based on the ideXlab platform.
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Rumination of different-sized particles in muskoxen (Ovibos moschatus) and moose (Alces alces) on grass and browse diets, and implications for rumination in different ruminant feeding types
Mammalian Biology, 2013Co-Authors: Murielle Lauper, Isabel Lechner, Perry S Barboza, William B Collins, Jurgen Hummel, Daryl Codron, Marcus ClaussAbstract:The obligatory, periodic regurgitation of forestomach material and its subsequent re-mastication is the hallmark of the most diverse extant large herbivore group, the ruminants. Although the process of rumination is well understood in domestic species, differences between free-ranging wild ruminant species, for example of different body size or different feeding type, remain speculative to date. Here we investigate the proportion of plastic particles of varying size (1, 10 and 20mm) and density (1.03, 1.20 and 1.44 mg/ml) that are recovered intact or ruminated-upon after insertion into the reticulorumen (RR) of domestic cattle ( Bos primigenius f. taurus ) on grass silage, and of muskoxen ( Ovibos moschatus ; n =4) and moose ( Alces alces ; n =2) both fed browse and grass diets. In the three species, the proportion of particles leaving the RR intact depended on particle size, with density showing no effect in this study. The major proportion of 1 mm particles was excreted intact, whereas intact 10–20mm particles were only excreted sporadically, and not in all animals. Intact particles were mostly found in the initial samples after marker application, and mean retention times of intact particles were always shorter than those of ruminated particles. There were no differences between moose and muskoxen, but diet had a significant effect, with a higher proportion of 1 mm particles ruminated upon on the grass diet in both species, indicating a higher ‘filter-bed effect’ with entrapment of small particles in a fibre mat in the RR on a grass diet. Given that less particles were ruminated on the grass diet, one could either assume that free-ranging browsers ruminate less than grazers on similar food intakes (or that they have higher food intakes at similar levels of rumination). The existing data on time-budgets of free-ranging ruminants, however, does not suffice to test these hypotheses. The fact that indication of a ‘filter-bed effect’ was also detectable in moose raises the question whether adaptations described in ‘cattle-type’ ruminants really serve to re-inforce the processes of RR contents stratification and the ‘filter-bed’, or whether they are not rather directed at other aims, such as maximizing microbial yield from the RR.
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The effect of size and density on the mean retention time of particles in the reticulorumen of cattle ( Bos primigenius f. taurus), muskoxen ( Ovibos moschatus) and moose ( Alces alces).
The British journal of nutrition, 2010Co-Authors: Marcus Clauss, Isabel Lechner, Perry S Barboza, William B Collins, Karlheinz Sudekum, Daryl Codron, Theo A. Tervoort, Jurgen HummelAbstract:Particle passage from the reticulorumen (RR) depends on particle density and size. Forage particle density and size are related and change over time in the RR. Particle density mainly influences sorting in the reticulum, whereas particle size influences particle retention in the fibre mat of stratified rumen contents (‘filter-bed’ effect). We investigated these effects independently, by inserting plastic particles of different sizes (1, 10 and 20 mm) and densities (1·03, 1·20 and 1·44 mg/ml) in the RR of cattle ( Bos primigenius f. taurus ) as a pilot study, and of muskoxen ( Ovibos moschatus ; n 4) and moose ( Alces alces ; n 2) both fed two diets (browse and grass). Faeces were analysed for plastic residues for 13 d after dosing to calculate mean retention times (MRT). The results confirmed previous findings of differences in absolute MRT between species. Comparing muskoxen with moose, there was no difference in the effect of particle density on the MRT between species but particle size had a more pronounced effect on the MRT in muskoxen than in moose. This indicated a stronger ‘filter-bed effect’ in muskoxen, in accord with the reports of stratified RR contents in this species v. the absence of RR content stratification in moose. Low-density particles were retained longer in both species fed on grass diets, indicating a contribution of forage type to the ‘filter-bed effect’. The results indicate that retention based on particle size may differ between ruminant species, depending on the presence of a fibre mat in the RR, whereas the density-dependent mechanism of sedimentation in the RR is rather constant across species.
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differential passage of fluids and different sized particles in fistulated oxen bos primigenius f taurus muskoxen Ovibos moschatus reindeer rangifer tarandus and moose alces alces rumen particle size discrimination is independent from contents strati
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2010Co-Authors: Isabel Lechner, Perry S Barboza, William B Collins, Julia Fritz, Detlef Gunther, Bodo Hattendorf, Jurgen Hummel, Karlheinz Sudekum, Marcus ClaussAbstract:Ruminant species differ in the degree that their rumen contents are stratified but are similar insofar that only very fine particles are passed from the forestomach to the lower digestive tract. We investigated the passage kinetics of fluid and particle markers (2, 10 and 20 mm) in fistulated cattle (Bos primigenius f. taurus), muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose (Alces alces) on different diets. The distribution of dry matter in the rumen and the viscosity of rumen fluids suggested that the rumen contents were more stratified in muskoxen than moose. Correspondingly, as in previous studies, the species differed in the ratio of mean retention times of small particles to fluids in the reticulorumen, which was highest in cattle (2.03) and muskoxen (1.97-1.98), intermediate in reindeer (1.70) and lowest in moose (0.98-1.29). However, the ratio of large to small particle retention did not differ between the species, indicating similarity in the efficiency of the particle sorting mechanism. Passage kinetics of the two largest particle classes did not differ, indicating that particle retention is not a continuous function of particle size but rather threshold-dependent. Overall, the results suggest that fluid flow through the forestomach differs between ruminant species. A lower relative fluid passage, such as in moose, might limit species to a browse-based dietary niche, whereas a higher relative fluid passage broadens the dietary niche options and facilitates the inclusion of, or specialization on, grass. The function of fluid flow in the ruminant forestomach should be further investigated.
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Surface enlargement in the rumen of free-ranging muskoxen (Ovibos moschatus)
European Journal of Wildlife Research, 2009Co-Authors: Marcus Clauss, Jan Adamczewski, Reinhold R. HofmannAbstract:The intraruminal papillation pattern indicates the degree of rumen contents stratification and is related to the feeding niche of a ruminant. Muskoxen (Ovibos moschatus) display a variety of morphophysiological adaptations typical for grazers. We investigated the intraruminal papillation of 22 free-ranging muskoxen from five different months by comparing the surface enlargement factor both between seasons and between individual rumen regions. The seasonal pattern of rumen papillation indicated a distinct seasonality in food quality. The intraruminal papillation indicated a moderate degree of rumen contents stratification typical for intermediate feeders. The nutritional ecology of muskoxen is characterised by specific morphophysiological adaptations to a grass-dominated diet that nevertheless allow extensive seasonal use of browse forage.
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No 'bypass' in adult ruminants: passage of fluid ingested vs. fluid inserted into the rumen in fistulated muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose (Alces alces).
Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 2009Co-Authors: Isabel Lechner, Perry S Barboza, William B Collins, Detlef Gunther, Bodo Hattendorf, Jurgen Hummel, Marcus ClaussAbstract:In young ruminants, the reticular groove ensures that ingested milk is channelled past the forestomach to avoid malfermentation. It has been speculated that some adult wild ruminants, in particular browsing species, maintain a functional oesophageal (reticular) groove, that soluble nutrients can thus bypass the rumen, and that thus the energetic gain from the diet can be increased. We inserted a fluid marker (Co-EDTA) via cannula into the rumen and simultaneously fed a diet that contained a second fluid marker (Sm-EDTA), and analysed the faecal marker excretion patterns, in muskoxen (Ovibos moschatus, n=4 in two experiments each), reindeer (Rangifer tarandus, n=4 in a total of six experiments) and moose (Alces alces, n=1 in one experiment). In no case was the orally fed marker excreted dinstinctively earlier than the marker inserted into the rumen, which indicates that substantial bypass did not occur in these animals. However, differences between the three species in the excretion of the two markers from the rumen are consistent with hypothetical differences in the stratification of rumen contents. We suggest that effects previously ascribed to a “rumen bypass” in wild ruminants most likely reflect differences in the passage from the rumen.
Susan J. Kutz - One of the best experts on this subject based on the ideXlab platform.
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qiviut cortisol reflects hypothalamic pituitary adrenal axis activity in muskoxen Ovibos moschatus
General and Comparative Endocrinology, 2021Co-Authors: J. Di Francesco, Sylvia Checkley, John E. Blake, J. E. Rowell, G.f. Mastromonaco, Susan J. KutzAbstract:Muskoxen (Ovibos moschatus) are increasingly exposed to a broad diversity of stressors in their rapidly changing Arctic environment. There is an urgent need to develop validated tools to monitor the impact of these stressors on the hypothalamic-pituitary-adrenal (HPA) axis activity of muskoxen to help inform conservation actions. Here, we evaluated whether muskox qiviut (dense wooly undercoat) cortisol accurately reflects changes in HPA axis activity. Two repeated pharmacological challenges, involving weekly administrations of saline (control group) or adrenocorticotropic hormone (ACTH) during five consecutive weeks, were done on captive muskoxen, in winter (no hair growth) and summer (maximum hair growth). Pre-challenge qiviut cortisol levels were significantly higher in the shoulder than in the neck, but neither differed from rump concentrations. Qiviut cortisol levels significantly increased (p < 0.001) in response to the administration of ACTH during the hair growth phase, but not in the absence of growth (p = 0.84). Cortisol levels in the qiviut segment grown during the summer challenge increased significantly over a six-month period in the ACTH-injected muskoxen with a similar trend occurring in the control animals. Finally, cortisol levels in shed qiviut were significantly higher and not correlated to those of fully grown qiviut shaved three months earlier. Our results show that cortisol is deposited in qiviut during its growth and that qiviut cortisol can thus be used as an integrated measure of HPA axis activity over the period of the hair's growth. Differences in qiviut cortisol across body regions, significant differences in qiviut segments over time, and differences between shed qiviut versus unshed qiviut, highlight the importance of consistent design and methodology for sample collection and analyses in order to account for sources of variation when using qiviut cortisol as a biomarker of HPA axis activity in muskoxen.
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Qiviut cortisol reflects hypothalamic-pituitary-adrenal axis activity in muskoxen (Ovibos moschatus).
General and comparative endocrinology, 2021Co-Authors: J. Di Francesco, Sylvia Checkley, John E. Blake, J. E. Rowell, G.f. Mastromonaco, Susan J. KutzAbstract:Muskoxen (Ovibos moschatus) are increasingly exposed to a broad diversity of stressors in their rapidly changing Arctic environment. There is an urgent need to develop validated tools to monitor the impact of these stressors on the hypothalamic-pituitary-adrenal (HPA) axis activity of muskoxen to help inform conservation actions. Here, we evaluated whether muskox qiviut (dense wooly undercoat) cortisol accurately reflects changes in HPA axis activity. Two repeated pharmacological challenges, involving weekly administrations of saline (control group) or adrenocorticotropic hormone (ACTH) during five consecutive weeks, were done on captive muskoxen, in winter (no hair growth) and summer (maximum hair growth). Pre-challenge qiviut cortisol levels were significantly higher in the shoulder than in the neck, but neither differed from rump concentrations. Qiviut cortisol levels significantly increased (p
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Corynebacterium freneyi Bacterial Septicemia Secondary to Contagious Ecthyma in a Wild Muskox (Ovibos moschatus).
Journal of wildlife diseases, 2021Co-Authors: Jamie L. Rothenburger, Frank Van Der Meer, Matilde Tomaselli, Juliette Di Francesco, Lisa-marie Leclerc, Erin Zabek, Susan J. KutzAbstract:A wild muskox (Ovibos moschatus) with dermatitis typical of contagious ecthyma had secondary bacterial septicemia with Corynebacterium freneyi that included laminitis, hepatitis, and suppurative encephalitis. This case supports the association between orf virus infection and fatal secondary infections, which may have contributed to population declines on Victoria Island, Canada.
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Contagious Ecthyma, Rangiferine Brucellosis, and Lungworm Infection in a Muskox (Ovibos moschatus) from the Canadian Arctic, 2014
Journal of wildlife diseases, 2016Co-Authors: Matilde Tomaselli, Pratap Kafle, Susan J. Kutz, Frank Van Der Meer, Chimoné S. Dalton, Pádraig J. Duignan, Om P. Surujballi, Claude Turcotte, Sylvia CheckleyAbstract:Abstract An adult male muskox (Ovibos moschatus), harvested on 26 August 2014 on Victoria Island, Nunavut, in the Canadian Arctic, had proliferative dermatitis on the muzzle and fetlocks suggestive of contagious ecthyma or orf (Parapoxvirus). Histopathologic features of the lesions were consistent with this diagnosis. Orf virus DNA, phylogenetically similar to an isolate from a captive muskox of the Minnesota Zoo, US, was detected in the lesions by PCR using Parapoxvirus primers. Additionally, there was a metaphyseal abscess with a cortical fistula in the right metacarpus from which Brucella suis biovar 4 was isolated and identification supported by PCR. Brucella spp. antibodies were detected in serum. Finally, 212 nodules were dissected from the lungs. Fecal analysis and lung examination demonstrated co-infection with the lungworms Umingmakstrongylus pallikuukensis and Varestrongylus eleguneniensis. The zoonotic potential of orf and rangiferine brucellosis adds an important public health dimension to thi...
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Discovery and Description of the “Davtiani” Morphotype for Teladorsagia boreoarcticus (Trichostrongyloidea: Ostertagiinae) Abomasal Parasites In Muskoxen, Ovibos moschatus, and Caribou, Rangifer tarandus, from the North American Arctic: Implications
The Journal of parasitology, 2011Co-Authors: Eric P. Hoberg, Arthur Abrams, Patricia A. Pilitt, Susan J. KutzAbstract:Abstract: Collections to explore helminth diversity among free-ranging ungulates in the North American Arctic revealed the occurrence of a third male, or “davtiani,” morphotype for Teladorsagia boreoarcticus. Designated as T. boreoarcticus forma (f.) minor B, the males occurred with T. boreoarcticus f. major and T. borearcticus f. minor A in endemic populations of muskoxen (Ovibos moschatus wardi) and barrenground caribou (Rangifer tarandus groenlandicus) on Victoria Island, Nunavut, Canada, and in muskoxen and Peary caribou (Rangifer tarandus pearyi) on Banks Island, Northwest Territories, Canada. These specimens differ from conspecific morphotypes in the structure of the genital cone and Sjoberg's organ. Relative to T. boreoarcticus f. minor A, specimens of T. boreoarcticus f. minor B are consistently smaller, and mean dimensions for the bursa and spicules do not overlap. The robust spicules are similar in form, particularly in the relative length of the dorsal and ventral processes, but mean total leng...
Jurgen Hummel - One of the best experts on this subject based on the ideXlab platform.
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Rumination of different-sized particles in muskoxen (Ovibos moschatus) and moose (Alces alces) on grass and browse diets, and implications for rumination in different ruminant feeding types
Mammalian Biology, 2013Co-Authors: Murielle Lauper, Isabel Lechner, Perry S Barboza, William B Collins, Jurgen Hummel, Daryl Codron, Marcus ClaussAbstract:The obligatory, periodic regurgitation of forestomach material and its subsequent re-mastication is the hallmark of the most diverse extant large herbivore group, the ruminants. Although the process of rumination is well understood in domestic species, differences between free-ranging wild ruminant species, for example of different body size or different feeding type, remain speculative to date. Here we investigate the proportion of plastic particles of varying size (1, 10 and 20mm) and density (1.03, 1.20 and 1.44 mg/ml) that are recovered intact or ruminated-upon after insertion into the reticulorumen (RR) of domestic cattle ( Bos primigenius f. taurus ) on grass silage, and of muskoxen ( Ovibos moschatus ; n =4) and moose ( Alces alces ; n =2) both fed browse and grass diets. In the three species, the proportion of particles leaving the RR intact depended on particle size, with density showing no effect in this study. The major proportion of 1 mm particles was excreted intact, whereas intact 10–20mm particles were only excreted sporadically, and not in all animals. Intact particles were mostly found in the initial samples after marker application, and mean retention times of intact particles were always shorter than those of ruminated particles. There were no differences between moose and muskoxen, but diet had a significant effect, with a higher proportion of 1 mm particles ruminated upon on the grass diet in both species, indicating a higher ‘filter-bed effect’ with entrapment of small particles in a fibre mat in the RR on a grass diet. Given that less particles were ruminated on the grass diet, one could either assume that free-ranging browsers ruminate less than grazers on similar food intakes (or that they have higher food intakes at similar levels of rumination). The existing data on time-budgets of free-ranging ruminants, however, does not suffice to test these hypotheses. The fact that indication of a ‘filter-bed effect’ was also detectable in moose raises the question whether adaptations described in ‘cattle-type’ ruminants really serve to re-inforce the processes of RR contents stratification and the ‘filter-bed’, or whether they are not rather directed at other aims, such as maximizing microbial yield from the RR.
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The effect of size and density on the mean retention time of particles in the reticulorumen of cattle ( Bos primigenius f. taurus), muskoxen ( Ovibos moschatus) and moose ( Alces alces).
The British journal of nutrition, 2010Co-Authors: Marcus Clauss, Isabel Lechner, Perry S Barboza, William B Collins, Karlheinz Sudekum, Daryl Codron, Theo A. Tervoort, Jurgen HummelAbstract:Particle passage from the reticulorumen (RR) depends on particle density and size. Forage particle density and size are related and change over time in the RR. Particle density mainly influences sorting in the reticulum, whereas particle size influences particle retention in the fibre mat of stratified rumen contents (‘filter-bed’ effect). We investigated these effects independently, by inserting plastic particles of different sizes (1, 10 and 20 mm) and densities (1·03, 1·20 and 1·44 mg/ml) in the RR of cattle ( Bos primigenius f. taurus ) as a pilot study, and of muskoxen ( Ovibos moschatus ; n 4) and moose ( Alces alces ; n 2) both fed two diets (browse and grass). Faeces were analysed for plastic residues for 13 d after dosing to calculate mean retention times (MRT). The results confirmed previous findings of differences in absolute MRT between species. Comparing muskoxen with moose, there was no difference in the effect of particle density on the MRT between species but particle size had a more pronounced effect on the MRT in muskoxen than in moose. This indicated a stronger ‘filter-bed effect’ in muskoxen, in accord with the reports of stratified RR contents in this species v. the absence of RR content stratification in moose. Low-density particles were retained longer in both species fed on grass diets, indicating a contribution of forage type to the ‘filter-bed effect’. The results indicate that retention based on particle size may differ between ruminant species, depending on the presence of a fibre mat in the RR, whereas the density-dependent mechanism of sedimentation in the RR is rather constant across species.
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differential passage of fluids and different sized particles in fistulated oxen bos primigenius f taurus muskoxen Ovibos moschatus reindeer rangifer tarandus and moose alces alces rumen particle size discrimination is independent from contents strati
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2010Co-Authors: Isabel Lechner, Perry S Barboza, William B Collins, Julia Fritz, Detlef Gunther, Bodo Hattendorf, Jurgen Hummel, Karlheinz Sudekum, Marcus ClaussAbstract:Ruminant species differ in the degree that their rumen contents are stratified but are similar insofar that only very fine particles are passed from the forestomach to the lower digestive tract. We investigated the passage kinetics of fluid and particle markers (2, 10 and 20 mm) in fistulated cattle (Bos primigenius f. taurus), muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose (Alces alces) on different diets. The distribution of dry matter in the rumen and the viscosity of rumen fluids suggested that the rumen contents were more stratified in muskoxen than moose. Correspondingly, as in previous studies, the species differed in the ratio of mean retention times of small particles to fluids in the reticulorumen, which was highest in cattle (2.03) and muskoxen (1.97-1.98), intermediate in reindeer (1.70) and lowest in moose (0.98-1.29). However, the ratio of large to small particle retention did not differ between the species, indicating similarity in the efficiency of the particle sorting mechanism. Passage kinetics of the two largest particle classes did not differ, indicating that particle retention is not a continuous function of particle size but rather threshold-dependent. Overall, the results suggest that fluid flow through the forestomach differs between ruminant species. A lower relative fluid passage, such as in moose, might limit species to a browse-based dietary niche, whereas a higher relative fluid passage broadens the dietary niche options and facilitates the inclusion of, or specialization on, grass. The function of fluid flow in the ruminant forestomach should be further investigated.
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No 'bypass' in adult ruminants: passage of fluid ingested vs. fluid inserted into the rumen in fistulated muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose (Alces alces).
Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 2009Co-Authors: Isabel Lechner, Perry S Barboza, William B Collins, Detlef Gunther, Bodo Hattendorf, Jurgen Hummel, Marcus ClaussAbstract:In young ruminants, the reticular groove ensures that ingested milk is channelled past the forestomach to avoid malfermentation. It has been speculated that some adult wild ruminants, in particular browsing species, maintain a functional oesophageal (reticular) groove, that soluble nutrients can thus bypass the rumen, and that thus the energetic gain from the diet can be increased. We inserted a fluid marker (Co-EDTA) via cannula into the rumen and simultaneously fed a diet that contained a second fluid marker (Sm-EDTA), and analysed the faecal marker excretion patterns, in muskoxen (Ovibos moschatus, n=4 in two experiments each), reindeer (Rangifer tarandus, n=4 in a total of six experiments) and moose (Alces alces, n=1 in one experiment). In no case was the orally fed marker excreted dinstinctively earlier than the marker inserted into the rumen, which indicates that substantial bypass did not occur in these animals. However, differences between the three species in the excretion of the two markers from the rumen are consistent with hypothetical differences in the stratification of rumen contents. We suggest that effects previously ascribed to a “rumen bypass” in wild ruminants most likely reflect differences in the passage from the rumen.
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macroscopic anatomy of the omasum of free ranging moose alces alces and muskoxen Ovibos moschatus and a comparison of the omasal laminal surface area in 34 ruminant species
Journal of Zoology, 2006Co-Authors: Marcus Clauss, Jurgen Hummel, R R Hofmann, J Adamczewski, K Nygren, C Pitra, W J Streich, Sven ReeseAbstract:The function of the 'third compartment' of the ruminant forestomach, the omasum, has been debated for a long time. To date, it is assumed that its major function is fluid reabsorption. In order to investigate differences in this organ between ruminant feeding types, we first compared macroscopic measurements of the omasa of free-ranging muskoxen Ovibos moschatus [n=6, mean body mass (BM) 207 kg, range 180-221], a grazer, and free-ranging moose Alces alces (n=11, mean BM 291 kg, range 144-418), a strict browser. Despite the similar BM range, omasa of muskoxen contained more ingesta, had a higher empty organ weight, had more third- and fourth-order laminae, and represented a higher proportion of the total forestomach weight. In particular, the surface area of the omasal leaves - the area available for fluid absorption - was significantly larger in muskoxen (10 933 +/- 940 cm(2)) than in moose (2228 +/- 885 cm(2)). In order to test whether the difference in available surface area is a true functional correlate of feeding type, additional data on the omasal laminar surface area were generated for 83 individuals of 19 species. These data were supplemented with data on 13 additional species from the literature. The percentage of grass (%grass) in the natural diet was used to characterize the feeding type; the phylogenetic tree used for a controlled statistical evaluation was entirely based on mitochondrial DNA information. Regardless of phylogenetic control in the statistical treatment, there was a significant positive correlation of both BM and %grass in the natural diet with omasal laminar surface area. The data suggest that certain ruminant species that ingest more grass have larger omasal leaf surface areas, possibly indicating a higher need for water reabsorption distal to the ruminoreticulum, which could be explained as a consequence of the more distinct rumen contents stratification in these species.
Perry S Barboza - One of the best experts on this subject based on the ideXlab platform.
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Rumination of different-sized particles in muskoxen (Ovibos moschatus) and moose (Alces alces) on grass and browse diets, and implications for rumination in different ruminant feeding types
Mammalian Biology, 2013Co-Authors: Murielle Lauper, Isabel Lechner, Perry S Barboza, William B Collins, Jurgen Hummel, Daryl Codron, Marcus ClaussAbstract:The obligatory, periodic regurgitation of forestomach material and its subsequent re-mastication is the hallmark of the most diverse extant large herbivore group, the ruminants. Although the process of rumination is well understood in domestic species, differences between free-ranging wild ruminant species, for example of different body size or different feeding type, remain speculative to date. Here we investigate the proportion of plastic particles of varying size (1, 10 and 20mm) and density (1.03, 1.20 and 1.44 mg/ml) that are recovered intact or ruminated-upon after insertion into the reticulorumen (RR) of domestic cattle ( Bos primigenius f. taurus ) on grass silage, and of muskoxen ( Ovibos moschatus ; n =4) and moose ( Alces alces ; n =2) both fed browse and grass diets. In the three species, the proportion of particles leaving the RR intact depended on particle size, with density showing no effect in this study. The major proportion of 1 mm particles was excreted intact, whereas intact 10–20mm particles were only excreted sporadically, and not in all animals. Intact particles were mostly found in the initial samples after marker application, and mean retention times of intact particles were always shorter than those of ruminated particles. There were no differences between moose and muskoxen, but diet had a significant effect, with a higher proportion of 1 mm particles ruminated upon on the grass diet in both species, indicating a higher ‘filter-bed effect’ with entrapment of small particles in a fibre mat in the RR on a grass diet. Given that less particles were ruminated on the grass diet, one could either assume that free-ranging browsers ruminate less than grazers on similar food intakes (or that they have higher food intakes at similar levels of rumination). The existing data on time-budgets of free-ranging ruminants, however, does not suffice to test these hypotheses. The fact that indication of a ‘filter-bed effect’ was also detectable in moose raises the question whether adaptations described in ‘cattle-type’ ruminants really serve to re-inforce the processes of RR contents stratification and the ‘filter-bed’, or whether they are not rather directed at other aims, such as maximizing microbial yield from the RR.
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The effect of size and density on the mean retention time of particles in the reticulorumen of cattle ( Bos primigenius f. taurus), muskoxen ( Ovibos moschatus) and moose ( Alces alces).
The British journal of nutrition, 2010Co-Authors: Marcus Clauss, Isabel Lechner, Perry S Barboza, William B Collins, Karlheinz Sudekum, Daryl Codron, Theo A. Tervoort, Jurgen HummelAbstract:Particle passage from the reticulorumen (RR) depends on particle density and size. Forage particle density and size are related and change over time in the RR. Particle density mainly influences sorting in the reticulum, whereas particle size influences particle retention in the fibre mat of stratified rumen contents (‘filter-bed’ effect). We investigated these effects independently, by inserting plastic particles of different sizes (1, 10 and 20 mm) and densities (1·03, 1·20 and 1·44 mg/ml) in the RR of cattle ( Bos primigenius f. taurus ) as a pilot study, and of muskoxen ( Ovibos moschatus ; n 4) and moose ( Alces alces ; n 2) both fed two diets (browse and grass). Faeces were analysed for plastic residues for 13 d after dosing to calculate mean retention times (MRT). The results confirmed previous findings of differences in absolute MRT between species. Comparing muskoxen with moose, there was no difference in the effect of particle density on the MRT between species but particle size had a more pronounced effect on the MRT in muskoxen than in moose. This indicated a stronger ‘filter-bed effect’ in muskoxen, in accord with the reports of stratified RR contents in this species v. the absence of RR content stratification in moose. Low-density particles were retained longer in both species fed on grass diets, indicating a contribution of forage type to the ‘filter-bed effect’. The results indicate that retention based on particle size may differ between ruminant species, depending on the presence of a fibre mat in the RR, whereas the density-dependent mechanism of sedimentation in the RR is rather constant across species.
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differential passage of fluids and different sized particles in fistulated oxen bos primigenius f taurus muskoxen Ovibos moschatus reindeer rangifer tarandus and moose alces alces rumen particle size discrimination is independent from contents strati
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2010Co-Authors: Isabel Lechner, Perry S Barboza, William B Collins, Julia Fritz, Detlef Gunther, Bodo Hattendorf, Jurgen Hummel, Karlheinz Sudekum, Marcus ClaussAbstract:Ruminant species differ in the degree that their rumen contents are stratified but are similar insofar that only very fine particles are passed from the forestomach to the lower digestive tract. We investigated the passage kinetics of fluid and particle markers (2, 10 and 20 mm) in fistulated cattle (Bos primigenius f. taurus), muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose (Alces alces) on different diets. The distribution of dry matter in the rumen and the viscosity of rumen fluids suggested that the rumen contents were more stratified in muskoxen than moose. Correspondingly, as in previous studies, the species differed in the ratio of mean retention times of small particles to fluids in the reticulorumen, which was highest in cattle (2.03) and muskoxen (1.97-1.98), intermediate in reindeer (1.70) and lowest in moose (0.98-1.29). However, the ratio of large to small particle retention did not differ between the species, indicating similarity in the efficiency of the particle sorting mechanism. Passage kinetics of the two largest particle classes did not differ, indicating that particle retention is not a continuous function of particle size but rather threshold-dependent. Overall, the results suggest that fluid flow through the forestomach differs between ruminant species. A lower relative fluid passage, such as in moose, might limit species to a browse-based dietary niche, whereas a higher relative fluid passage broadens the dietary niche options and facilitates the inclusion of, or specialization on, grass. The function of fluid flow in the ruminant forestomach should be further investigated.
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No 'bypass' in adult ruminants: passage of fluid ingested vs. fluid inserted into the rumen in fistulated muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose (Alces alces).
Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 2009Co-Authors: Isabel Lechner, Perry S Barboza, William B Collins, Detlef Gunther, Bodo Hattendorf, Jurgen Hummel, Marcus ClaussAbstract:In young ruminants, the reticular groove ensures that ingested milk is channelled past the forestomach to avoid malfermentation. It has been speculated that some adult wild ruminants, in particular browsing species, maintain a functional oesophageal (reticular) groove, that soluble nutrients can thus bypass the rumen, and that thus the energetic gain from the diet can be increased. We inserted a fluid marker (Co-EDTA) via cannula into the rumen and simultaneously fed a diet that contained a second fluid marker (Sm-EDTA), and analysed the faecal marker excretion patterns, in muskoxen (Ovibos moschatus, n=4 in two experiments each), reindeer (Rangifer tarandus, n=4 in a total of six experiments) and moose (Alces alces, n=1 in one experiment). In no case was the orally fed marker excreted dinstinctively earlier than the marker inserted into the rumen, which indicates that substantial bypass did not occur in these animals. However, differences between the three species in the excretion of the two markers from the rumen are consistent with hypothetical differences in the stratification of rumen contents. We suggest that effects previously ascribed to a “rumen bypass” in wild ruminants most likely reflect differences in the passage from the rumen.
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Sensible heat loss from Muskoxen (Ovibos moschatus) feeding in winter: small calves are not at a thermal disadvantage compared with adult cows.
Physiological and biochemical zoology : PBZ, 2009Co-Authors: Adam J. Munn, Perry S Barboza, Jon DehnAbstract:Abstract Muskoxen (Ovibos moschatus) are large (>200 kg adult body mass) mammalian herbivores that overwinter in the polar regions. Calves are around one‐third the body mass of mature females and may be expected to suffer greater thermal stresses in winter compared with adults because the ratio of surface area to volume (SA:vol) is much greater for calves than for adults. We found that during feeding bouts, when animals are fully exposed to environmental conditions, calves did lose sensible (dry) heat more readily than adults (W m−2) in still air conditions. However, calves and cows lost less than 2%–6% of their estimated daily digestible energy intake as conductive, convective, and radiant heat losses accumulated during feeding bouts. More important, calves did not lose relatively more heat than larger adults in terms of sensible losses as part of their daily energy intake. Coat surface temperatures were only 2°–5°C above ambient even when air temperature fell to −40°C. Body temperatures recorded deep wi...
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Rumination of different-sized particles in muskoxen (Ovibos moschatus) and moose (Alces alces) on grass and browse diets, and implications for rumination in different ruminant feeding types
Mammalian Biology, 2013Co-Authors: Murielle Lauper, Isabel Lechner, Perry S Barboza, William B Collins, Jurgen Hummel, Daryl Codron, Marcus ClaussAbstract:The obligatory, periodic regurgitation of forestomach material and its subsequent re-mastication is the hallmark of the most diverse extant large herbivore group, the ruminants. Although the process of rumination is well understood in domestic species, differences between free-ranging wild ruminant species, for example of different body size or different feeding type, remain speculative to date. Here we investigate the proportion of plastic particles of varying size (1, 10 and 20mm) and density (1.03, 1.20 and 1.44 mg/ml) that are recovered intact or ruminated-upon after insertion into the reticulorumen (RR) of domestic cattle ( Bos primigenius f. taurus ) on grass silage, and of muskoxen ( Ovibos moschatus ; n =4) and moose ( Alces alces ; n =2) both fed browse and grass diets. In the three species, the proportion of particles leaving the RR intact depended on particle size, with density showing no effect in this study. The major proportion of 1 mm particles was excreted intact, whereas intact 10–20mm particles were only excreted sporadically, and not in all animals. Intact particles were mostly found in the initial samples after marker application, and mean retention times of intact particles were always shorter than those of ruminated particles. There were no differences between moose and muskoxen, but diet had a significant effect, with a higher proportion of 1 mm particles ruminated upon on the grass diet in both species, indicating a higher ‘filter-bed effect’ with entrapment of small particles in a fibre mat in the RR on a grass diet. Given that less particles were ruminated on the grass diet, one could either assume that free-ranging browsers ruminate less than grazers on similar food intakes (or that they have higher food intakes at similar levels of rumination). The existing data on time-budgets of free-ranging ruminants, however, does not suffice to test these hypotheses. The fact that indication of a ‘filter-bed effect’ was also detectable in moose raises the question whether adaptations described in ‘cattle-type’ ruminants really serve to re-inforce the processes of RR contents stratification and the ‘filter-bed’, or whether they are not rather directed at other aims, such as maximizing microbial yield from the RR.
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The effect of size and density on the mean retention time of particles in the reticulorumen of cattle ( Bos primigenius f. taurus), muskoxen ( Ovibos moschatus) and moose ( Alces alces).
The British journal of nutrition, 2010Co-Authors: Marcus Clauss, Isabel Lechner, Perry S Barboza, William B Collins, Karlheinz Sudekum, Daryl Codron, Theo A. Tervoort, Jurgen HummelAbstract:Particle passage from the reticulorumen (RR) depends on particle density and size. Forage particle density and size are related and change over time in the RR. Particle density mainly influences sorting in the reticulum, whereas particle size influences particle retention in the fibre mat of stratified rumen contents (‘filter-bed’ effect). We investigated these effects independently, by inserting plastic particles of different sizes (1, 10 and 20 mm) and densities (1·03, 1·20 and 1·44 mg/ml) in the RR of cattle ( Bos primigenius f. taurus ) as a pilot study, and of muskoxen ( Ovibos moschatus ; n 4) and moose ( Alces alces ; n 2) both fed two diets (browse and grass). Faeces were analysed for plastic residues for 13 d after dosing to calculate mean retention times (MRT). The results confirmed previous findings of differences in absolute MRT between species. Comparing muskoxen with moose, there was no difference in the effect of particle density on the MRT between species but particle size had a more pronounced effect on the MRT in muskoxen than in moose. This indicated a stronger ‘filter-bed effect’ in muskoxen, in accord with the reports of stratified RR contents in this species v. the absence of RR content stratification in moose. Low-density particles were retained longer in both species fed on grass diets, indicating a contribution of forage type to the ‘filter-bed effect’. The results indicate that retention based on particle size may differ between ruminant species, depending on the presence of a fibre mat in the RR, whereas the density-dependent mechanism of sedimentation in the RR is rather constant across species.
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differential passage of fluids and different sized particles in fistulated oxen bos primigenius f taurus muskoxen Ovibos moschatus reindeer rangifer tarandus and moose alces alces rumen particle size discrimination is independent from contents strati
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2010Co-Authors: Isabel Lechner, Perry S Barboza, William B Collins, Julia Fritz, Detlef Gunther, Bodo Hattendorf, Jurgen Hummel, Karlheinz Sudekum, Marcus ClaussAbstract:Ruminant species differ in the degree that their rumen contents are stratified but are similar insofar that only very fine particles are passed from the forestomach to the lower digestive tract. We investigated the passage kinetics of fluid and particle markers (2, 10 and 20 mm) in fistulated cattle (Bos primigenius f. taurus), muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose (Alces alces) on different diets. The distribution of dry matter in the rumen and the viscosity of rumen fluids suggested that the rumen contents were more stratified in muskoxen than moose. Correspondingly, as in previous studies, the species differed in the ratio of mean retention times of small particles to fluids in the reticulorumen, which was highest in cattle (2.03) and muskoxen (1.97-1.98), intermediate in reindeer (1.70) and lowest in moose (0.98-1.29). However, the ratio of large to small particle retention did not differ between the species, indicating similarity in the efficiency of the particle sorting mechanism. Passage kinetics of the two largest particle classes did not differ, indicating that particle retention is not a continuous function of particle size but rather threshold-dependent. Overall, the results suggest that fluid flow through the forestomach differs between ruminant species. A lower relative fluid passage, such as in moose, might limit species to a browse-based dietary niche, whereas a higher relative fluid passage broadens the dietary niche options and facilitates the inclusion of, or specialization on, grass. The function of fluid flow in the ruminant forestomach should be further investigated.
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No 'bypass' in adult ruminants: passage of fluid ingested vs. fluid inserted into the rumen in fistulated muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose (Alces alces).
Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 2009Co-Authors: Isabel Lechner, Perry S Barboza, William B Collins, Detlef Gunther, Bodo Hattendorf, Jurgen Hummel, Marcus ClaussAbstract:In young ruminants, the reticular groove ensures that ingested milk is channelled past the forestomach to avoid malfermentation. It has been speculated that some adult wild ruminants, in particular browsing species, maintain a functional oesophageal (reticular) groove, that soluble nutrients can thus bypass the rumen, and that thus the energetic gain from the diet can be increased. We inserted a fluid marker (Co-EDTA) via cannula into the rumen and simultaneously fed a diet that contained a second fluid marker (Sm-EDTA), and analysed the faecal marker excretion patterns, in muskoxen (Ovibos moschatus, n=4 in two experiments each), reindeer (Rangifer tarandus, n=4 in a total of six experiments) and moose (Alces alces, n=1 in one experiment). In no case was the orally fed marker excreted dinstinctively earlier than the marker inserted into the rumen, which indicates that substantial bypass did not occur in these animals. However, differences between the three species in the excretion of the two markers from the rumen are consistent with hypothetical differences in the stratification of rumen contents. We suggest that effects previously ascribed to a “rumen bypass” in wild ruminants most likely reflect differences in the passage from the rumen.
