No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Getting it out of the (digestive) system : hindgut fermenters and calcium
... For example, Böswald, Dobenecker [10] evaluated the dietary and fecal calcium levels of different ruminant species and they documented higher calcium absorption in hindgut fermenting species (Diceros bicornis, Dicerorhinus sumatrensis, Rhinoceros unicornis, Equus caballus, Tapirus terrestris, Elephas maximus, and Oryctolagus cuniculus) than domestic ruminants (Bos taurus, Ovis aries, and Capra capra). This higher calcium absorption in hindgut fermenter species removes excessive calcium from the intestine and might ensure higher availability for microbial fermentation [11]. The major excretory, as well as regulatory, route of calcium in hindgut fermenters, is the urine [11,12], while ruminants do not need to adopt such a bypass mechanism, as ruminal fermentation involves effectively recycling calcium into the rumen through saliva [13]. ...
... This higher calcium absorption in hindgut fermenter species removes excessive calcium from the intestine and might ensure higher availability for microbial fermentation [11]. The major excretory, as well as regulatory, route of calcium in hindgut fermenters, is the urine [11,12], while ruminants do not need to adopt such a bypass mechanism, as ruminal fermentation involves effectively recycling calcium into the rumen through saliva [13]. Calcium is well characterized regarding intestinal transportation and interactive ways with other minerals [5]. ...
... For example, changing dietary selenium and chromium contents results in a change in sheep's gut microbiota diversity [21][22][23]. The gut microbiota has a versatile nature, adjusting in accordance with the diet, physical environment, and health status of the animal [11,23], and thus, changing the fecal metabolomic profile in this experiment reflects the dietary calcium influence on gut microbiota composition [24]. As dietary calcium influences the gut microbiota, this suggests that calcium can alter the fermentation process, leading to changes in the production of short-chain fatty acids and other metabolites. ...
Yunnan semi-fine wool (YSFW) is a recently developed dual-purpose (meat and wool) sheep breed mainly found in Yunnan Province, China. Moreover, dietary calcium is essential for animal health and productivity. The current experiment aimed to investigate the impact of dietary calcium on sheep gut metabolite profile. For this, thirty YSFW rams (male, age = 10 months, and body weight = 40.37 ± 0.49 kg) were randomized into three groups (n = 10 rams/group), followed by a completely randomized design, and the groups were allotted to one of three dietary calcium levels (Q_1 = 0.50%, Q_3 = 0.73%, and Q_5 = 0.98% on a dry basis). The rams were fed ad libitum by feeding twice a day (at 08:00 and 17:00 h/day) throughout the experimental period (44 day). On the 21st day of the experiment, fecal samples were collected from 27 rams (9/group) and untargeted metabolite profiling was performed by using ultra-performance liquid chromatography. The PCA plot showed that the Q_5 group metabolites were clustered more tightly than for Q_1 and Q_3, respectively. The tightly clustering molecules were mainly alkaloids and their derivatives, benzenoids, lignans and related compounds, lipids, nucleotides, organic acids, and nitrogenous-based derivatives. According to the Kyoto Encyclopedia of Genes and Genomes pathway analysis, these molecules potentially contribute to metabolic pathways, biosynthesis of secondary metabolites, proteinaceous compounds, and the metabolism of the protein derivatives, particularly amino acids. The PLS-DA plots revealed a significant difference between the Q_1, Q_3, and Q_5 groups, suggesting that Q_5 had a clear separation across the groups. Based on the metabolomic analysis, feeding different levels of dietary calcium significantly changed the metabolomic profile of YSFW rams, which primarily entails metabolic pathways such as energy, protein, and lipid metabolism.
... 2009, Osborne et al . 2009 ) but differences in excretion of excess dietary calcium have been reported between chinchillas and guinea pigs (Clauss & Hummel 2008, Clauss et al . 2012. ...
... Urolithiasis in rabbits has been anecdotally associated with increased calcium in the diet (Klaphake & Paul-Murphy 2012 ), although a high calcium diet alone does not cause urolith formation (Clauss et al . 2012 ) Rabbits and guinea pigs excrete excess dietary calcium via urine and this mechanism has been proposed to make them more susceptible to development of calcium-containing uroliths (Clauss & Hummel 2008, Clauss et al . 2012. ...
Objective:
To evaluate the signalment, history, clinical signs, diagnostic test results, treatment and outcome of chinchillas diagnosed with urolithiasis.
Methods:
Medical records of 15 chinchillas diagnosed with urolithiasis were retrospectively reviewed.
Results:
All animals were male with a median age of 30 months (range: 11 to 132 months). Haematuria, pollakiuria and stranguria were the most common presenting complaints. Of 15 animals, 12 had abnormal physical abdominal examination, including pain and palpable cystic calculi. Uroliths were diagnosed in the urinary bladder, urethra or both. Nine animals had cystic calculi only. Four out of 6 chinchillas with urethral calculi were euthanased within 1 day of diagnosis. There was recurrence of cystic calculi following cystotomy in 5/10 animals and median time to recurrence was 68 days (range: 19 to 440 days). Median survival time in chinchilla with urolith recurrence was 391 days (range: 74 to 1074 days) following initial diagnosis. Disease-free follow-up time in 5/10 chinchillas without urolith recurrence following surgical removal was 2204 days (range: 1914 to 2535 days).
Clinical significance:
Cystic uroliths in male chinchillas carry a better prognosis than urethral uroliths. Recurrence of urolithiasis is common in chinchillas.
... Why urolithiasis is more common in guinea pigs can be explained by the different calcium metabolism. Guinea pigs excrete excess calcium similar to rabbits and other hindgut fermenting herbivores (Clauss and Hummel, 2008), which eliminate up to 75% of their absorbed calcium via urine (O'dell et al., 1957; Meyer et al., 1996 ). Chinchillas, however , eliminate excessive calcium to approximately 80% via faeces and only 1–3% via urine; nevertheless, their urine calcium concentration may display great individual variation (Hansen, 2012). ...
... Possibly, chinchillas can additionally afford this lower water intake also because they are not dependent on calcium elimination via urine (Hansen, 2012 ). Calcium elimination via urine has been interpreted as a particular adaptation to microbial fermentation of plant fibre in the hindgut, because microbes require phosphate, which might be made unavailable by calcium complexation unless calcium is deflected from the gut (Clauss and Hummel, 2008; Clauss et al., 2009 ). Theoretically, such a strategy imposes a constraint on water saving mechanisms, and the peculiarity of the chinchilla – which excretes calcium via faeces – could represent a special adaptation in this respect. ...
Chinchilla (Chinchilla laniger), degus (Octodon degus) and guinea pigs (Cavia porcellus) are South American rodents living in a semi-arid habitat with varying, species-specific adaptations to water deprivation. Nonetheless, several diseases have been linked to insufficient water intake when these species are kept as pets, such as urolithiasis or obstipation. This study evaluated preferences for drinking systems. Six animals of each species were given a choice between an open dish and a nipple drinker. Food intake and water intake were measured daily for 13 days. Chinchillas in this study had significantly lower water intakes than the other two species, indicating particular species-specific adaptations to aridity. All chinchillas favoured open dishes, whereas the degus and guinea pigs had variable individual preferences. Water intake of chinchillas was similar or higher in this study than in previous studies where nipple drinkers were used. The results indicate that degus and guinea pigs can meet their drinking water needs with nipple drinkers; for chinchillas, other drinking systems may be more adequate.
... By regression analysis in the form of Lucas-tests 21 , it is possible to test for uniformity of absorption and estimate the true nutrient digestibility. As an example, the calcium and phosphorus homeostasis was found to differ between species groups, which can be explained by their feeding/digestive strategies 18,22 . In the present study, we aimed ...
In laboratory animals, there is a scarcity of digestibility data under non-experimental conditions. Such data is important as basis to generate nutrient requirements, which contributes to the refinement of husbandry conditions. Digestibility trials can also help to identify patterns of absorption and potential factors that influence the digestibility. Thus, a digestibility trial with a pelleted diet used as standard feed in laboratory mice was conducted. To identify potential differences between genetic lines, inbred C57Bl/6 J and outbred CD1 mice (n = 18 each, male, 8 weeks-old, housed in groups of three) were used. For seven days, the feed intake was recorded and the total faeces per cage collected. Energy, crude nutrient and mineral content of diet and faecal samples were analyzed to calculate the apparent digestibility (aD). Apparent dry matter and energy digestibility did not differ between both lines investigated. The C57Bl/6 J mice had significantly higher aD of magnesium and potassium and a trend towards a lower aD of sodium than the mice of the CD1 outbred stock. Lucas-tests were performed to calculate the mean true digestibility of the nutrients and revealed a uniformity of the linear regression over data from both common laboratory mouse lines. The mean true digestibility of crude nutrients was > 90%, except for fibre, that of the minerals ranged between 66 and 97%.
... A peculiarity of equids-and many other hindgut fermentersis that calcium absorption exceeds requirements, and surplus calcium is excreted via the urinary tract [60][61][62][63] . A hypothetical explanation for this mechanism, that appears to unduly challenge the renal and urinary system, is that the microbiome in a fermentation chamber requires available phosphorus, which is supplied by saliva in foregut fermenters, but must be derived from digesta in hindgut fermenters; as calcium tends to bind to phosphorus, possibly rendering it unavailable for the microbes, hindgut fermenters remove it selectively from the digestive tract [64] . This mechanism might make the calcium metabolism of many hindgut fermenters comparatively independent from vitamin D [65 , 66] . ...
Like other members of the even-toed ungulates (the perissodactyls), equids once had a higher species diversity in the fossil record than they have today. This is generally explained in comparison to the enormous diversity of bovid ruminants. Theories on putative competitive disadvantages of equids include the use of a single toe as opposed to two toes per leg, the lack of a specific brain cooling (and hence water-saving) mechanism, longer gestation periods that delay reproductive output, and in particular digestive physiology. To date, there is no empirical support for the theory that equids fare better on low-quality forage than ruminants. In contrast to the traditional juxtaposition of hindgut and foregut fermenters, we suggest that it is more insightful to sketch the evolution of equid and ruminant digestive physiology as a case of convergence: both evolved a particularly high chewing efficacy in their respective groups, which facilitates comparatively high feed and hence energy intakes. But because the ruminant system, less based on tooth anatomy but more on a forestomach sorting mechanism, is more effective, equids depend more on high feed intakes than ruminants and may well be more susceptible to feed shortages. Arguably, the most under-emphasized characteristic of equids may be that in contrast to many other herbivores including ruminants and coprophageous hindgut fermenters, equids do not use the microbial biomass growing in their gastrointestinal tract. Equids display behavioral and morphophysiological adaptations to high feed intakes, and their cranial anatomy that facilitates the cropping of forage while performing grinding chewing at the same time might be unique. Rather than looking for explanations how equids are better adapted to their present niches than other organisms, considering them remnants of a different morphophysiological solution may be more appropriate.
... The most common urolith is calcium carbonate, which is radiopaque. 19 Similar to rabbits and other hindgut-fermenting herbivores, guinea pigs excrete excess calcium 53 and they can eliminate up to 75% of their absorbed calcium via urine. Urine specific gravity and pH highly influence crystallization. ...
Diseases of the urinary tract are reviewed, covering infectious (bacterial, viral, parasitic), degenerative, congenital, metabolic, nutritional, neoplastic, obstructive, and toxic causes. Some clinical presentations and diagnostic procedures are described for ferrets, rabbits, guinea pigs, hamsters, mice, rats, chinchillas, hedgehogs, and sugar gliders, as well as therapies.
... Rabbits appear predisposed to Ca-containing uroliths and nephrocalcinosis, because their Ca metabolism is characterized by a comparatively high absorption of Ca from the gut, Ca blood levels that reflect Ca intake and an excretion of surplus Ca via urine, which therefore contains a typical sludge (Mayrhofer and Pfeil, 1985; Cheeke, 1987; Kamphues, 1991; Redrobe, 2002; Eckermann-Ross, 2008). They share this characteristic with many other hindgut-fermenting herbivores (Clauss and Hummel, 2008). Consequently, it has been suggested that avoiding feeds with a high Ca content, such as legume hays, can help prevent urolith formation in rabbits (Kamphues, 1999; Eckermann-Ross, 2008). ...
Rabbits absorb more calcium (Ca) from their diet than they require, and excrete surplus via urine, which therefore contains a typical 'sludge'. This makes rabbits susceptible to Ca-containing uroliths. But given the Ca content of diets of free-ranging specimens, and the limited reports of urinary sludge and Ca contents in free-ranging lagomorphs, we can suspect that rabbits are naturally adapted to high urinary Ca loads. We fed four groups of New Zealand hybrid rabbits [n = 28, age at start 5-6 weeks) pelleted diets consisting of lucerne hay only (L, Ca 2.32% dry matter (DM)], lucerne:oats 1:1 (LG, Ca 1.36%), grass hay only (G, Ca 1.04%), or grass:oats 1:1 (GG, 0.83%) for 25 weeks, with water available ad libitum. Diets were not supplemented with Ca, phosphorus, or vitamin D. Rabbits on diets LG and GG had lower food and water intakes, lower faeces and urine output, grew faster and had higher body mass at slaughter (mainly attributable to adipose tissue). Apparent Ca digestibility decreased in the order L-LG-G/GG. Rabbits on L had larger and heavier kidneys, more urinary sediment at sonography, and a higher urinary Ca content than the other groups. No animal showed signs of urolithiasis/calcinosis at X-ray, sonography, or gross pathology. Kidney/aorta histology only sporadically indicated Ca deposits, with no systematic difference between groups. Under the conditions of the experiment, dietary Ca loads in legume hay do not appear problematic for rabbits, and other factors, such as water supply and level of activity may be important contributors to urolithiasis development in veterinary patients. However, due to the lower Ca content of grass hay, the significantly lower degree of urinary sludge formation, and the significantly higher water intake related with grass hay feeding, grass hay-dominated diets are to be recommended for rabbits in which urolithiasis prevention is an issue.
Hindgut fermenting herbivores from different vertebrate taxa, including tortoises, and among mammals some afrotheria, perissodactyla incl. equids, several rodents as well as lagomorphs absorb more calcium (Ca) from the digesta than they require, and excrete the surplus via urine. Both proximate and ultimate causes are elusive. It was suggested that this mechanism might ensure phosphorus availability for the hindgut microbiome by removing potentially complex-building Ca from the digesta. Here we use Ussing chamber experiments to show that rabbits (Oryctolagus cuniculus) maintained on four different diets (six animals/diet) increase active Ca absorption at increasing Ca levels. This contradicts the common assumption that at higher dietary levels, where passive uptake should be more prevalent, active transport can relax and hence supports the deliberate removal hypothesis. In the rabbits, this absorption was distinctively higher in the caecum than in the duodenum, which is unexpected in mammals. Additional quantification of the presence of two proteins involved in active Ca absorption (calbindin-D9K CB; vitamin D receptor, VDR) showed higher presence with higher dietary Ca. However, their detailed distribution across the intestinal tract and the diet groups suggests that other factors not investigated in this study must play major roles in Ca absorption in rabbits. Investigating strategies of herbivores to mitigate potential negative effects of Ca in the digesta on microbial activity and growth might represent a promising area of future research.
Quantitative differences in calcium and phosphorus metabolism between domestic species exist and can be visualised using data on calcium and phosphorus intake and faecal excretion. The parameter for analysing the results was defined as Δ = dietary calcium/phosphorus (Ca/P) ratio – faecal Ca/P ratio. In previous studies, hindgut fermenters had significantly higher Δ values than ruminants (sheep, cattle, goats), which was explained by the high calcium digestibilities in hindgut fermenters in contrast to highly efficient phosphorus recycling in ruminants. The first hypothesis of the present study was that different types of ruminants (grazer, browser, intermediate feeder) would show differences in Δ as a proxy for quantitative calcium and phosphorus metabolism. The second hypothesis was that camelids as functional, but not taxonomic ruminants would show Δ values similar to ruminants. We used herbivorous zoo animals (17 species, hindgut and foregut fermenters), which were kept on their regular diet without variation for 1 week. Then, faecal samples were obtained from the individual animals. Feed items and faecal samples were analysed for calcium and phosphorus, and dietary and faecal Ca/P ratios as well as Δ were calculated. A comparison of the species groups (one‐way ANOVA on ranks, p < 0.05) showed that zoo hindgut fermenters had significantly higher Δ values (0.67 ± 0.34) than camelids and zoo ruminants (–1.07 ± 0.35 and –1.87 ± 1.56). There was no significant difference between camelids, grazers (–1.49 ± 1.31), browsers (–1.63 ± 0.88) and intermediate feeders (–2.11 ± 1.76). The ruminant species from this study had markedly lower Δ than domestic ruminants from literature data. Especially intermediate feeders had low Δ, possibly due to more efficient phosphorus recycling than the domestic ruminants.
Background
The impact of dietary phosphorus (P) excess, especially on renal and cardiovascular health, has been investigated in several species, but little is known in dogs.
Objective
The aim of this study was to examine effects of different P sources on concentration and postprandial kinetics of selected parameters of P homeostasis in dogs.
Methods
Eight beagles received one control diet (P 0.5% dry matter [DM]) and three high P diets (poultry meal, NaH2PO4, and KH2PO4; P 1.7% DM) for 18d. Urine samples were collected pre- and postprandially while faeces were collected quantitatively for 5d and analysed for minerals. On day 18, blood was sampled 1h pre- and 0.5, 1, 1.5, 2, 3, 5 and 7h postprandially.
Results
Pi (KH2PO4, NaH2PO4) but not organic P caused an increased apparent P digestibility and significantly influenced kinetics of serum FGF23, parathyroid hormone, P, CrossLaps and bonespecific alkaline phosphatase, demonstrating a disrupted calcium (Ca) and P homeostasis with potential harm for renal, cardiovascular and skeletal health.
Conclusions
Results of feeding Pi to dogs indicate distinct disturbances of Ca and P metabolism, in contrast to organic sources. The use of Pi in food can therefore not be considered as safe. Further research, especially on dose and long-term effects, is warranted.
To investigate the relationship between faecal calcium (Ca) and phosphorus (P) excretion in different mammalian species, a meta-analysis on digestibility data derived from the literature was conducted. Seventy-three studies on carnivores, omnivores, large and small hindgut fermenters, ruminants and hippos (a total of 21 mammalian species, precondition for inclusion dietary Ca/P ratio 1.5/1 – 3.0/1) were analysed for Ca and P digestibility. Dietary Ca/P ratios were lower than faecal Ca/P ratios in carnivores, omnivores, ruminants and hippos. In hindgut fermenters, dietary Ca/P ratios were higher than faecal Ca/P ratios, indicating higher intestinal Ca absorption in these species. In all species investigated, there was a significant positive relationship between Ca intake and faecal Ca excretion and between P intake and faecal P excretion. In the biologically relevant range, these equations predicted lower faecal Ca losses in hindgut fermenters than ruminants, for faecal P vice versa. In all species, faecal Ca and P excretion correlated significantly. In carnivores, this highly linear correlation was exceptionally strong (R² = .92). Yet, the linearity of the correlation was questionable in omnivores and ruminants. Possibly, the strong linear correlation of faecal Ca and P excretion in carnivores is due to the formation of insoluble Ca/P complexes in their relatively short and simple gastrointestinal tract. Another hypothesis is that in carnivores, Ca homeostasis relies on modifying bone turnover to a higher degree than on changes in intestinal Ca absorption. For the formation of bone matrix, a constant ratio of Ca and P absorption is of advantage.
ResearchGate has not been able to resolve any references for this publication.