Adaptations in the large intestine allowing small animals to eat fibrous foods

Björnhag, Göran

doi:10.1017/cbo9780511661716.018

Cited by 38 publications

(38 citation statements)

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“…Due to the relative voluminous caeca in all the species in the present study, they may be classified as caecum fermenters where poor quality forages can be utilized which would otherwise not be possible due to their small body size (Cork et al, 1999). Small animals usually have a greater energy demand per unit body mass compared to larger animals (Björnhag, 1994). Therefore, smaller animals have to consume more food per unit body mass than larger animals consuming the same type of food.…”

Section: And Inmentioning

confidence: 99%

The comparative gastrointestinal morphology of five species of muroid rodents found in Saudi Arabia

Walters

Marais²,

Johnson³

et al. 2014

Journal of Morphology

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Meriones rex (King jird), Meriones libycus (Libyan jird), Acomys dimidiatus (Eastern spiny mouse), Acomys cahirinus (Egyptian spiny mouse) and Dipodillus dasyurus (Wagner's dipodil) are five species of small rodents of the superfamily Muroidea with distributions in Eastern Africa, Egypt and the desert regions of the Arabian Peninsula.Water is scarce in these regions and may result in relatively low-digestible food. The aim of the present study is to describe and compare the gastrointestinal tract (GIT) morphology and morphometry of these five species in order to elucidate whether morphology is influenced by phylogeny or dietary preference. All the species can be grouped in the family Muridae in two subfamilies and similarities were observed including the hemiglandular stomach and relatively large caecum. It could be concluded that phylogeny plays an important role in determining GIT morphology while diet plays a subordinate role in the desert rodents in the present study.

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Section: And Inmentioning

confidence: 99%

The comparative gastrointestinal morphology of five species of muroid rodents found in Saudi Arabia

Walters

Marais²,

Johnson³

et al. 2014

Journal of Morphology

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“…This mechanism is particularly used in small herbivorous mammals and has been studied extensively in the rabbit (Björnhag, 1981), marsupials (Björnhag, 1994;Hume and Moyle, 1995), and certain myomorph rodents such as the Scandinavian lemming and rat (Sperber et al, 1983), the guinea-pig and chinchilla (Holtenius and Björn-hag, 1985), as well as nutrias (Snipes et al, 1988).…”

Section: Introductionmentioning

confidence: 99%

The colonic groove or furrow: A comparative morphological study of six species of African mole‐rats (Rodentia, Bathyergidae)

Kotzé

Merwe

Ndou

et al. 2009

Journal of Morphology

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Herbivorous mammals such as nutrias, guinea pigs, chinchillas, and mole-rats have a longitudinal mucosal colonic groove (furrow) in their ascending colon, which is thought to play a role in the colonic separation mechanism (CSM). It is not known whether this groove is structurally modified to adapt to this function in mole-rat species. The morphology of this groove was studied in 32 mol-rats, four species, one of which consisted of three subspecies, endemic to southern Africa and two species found in eastern Africa. The macroscopic morphology of the groove was documented, and samples for histological examination were taken. The groove was wide at its origin at the cecocolic junction and was lined on either side by a row of papillae with the opposing papillae slightly offset in arrangement. The papillated groove gradually decreased in size toward the distal part of the ascending colon where it disappeared. This pattern was similar in all species except in Heterocephalus glaber, where the papillae were absent and the groove was lined by two longitudinal ridges. A histological examination of cross sections revealed that the mucosa covering the inner and outer walls of the groove was rich in mucous-secreting goblet cells. The walls of the groove contained smooth muscle extending from the inner circular smooth muscle layer at the base to the tips of the papillae in all species examined as well as arteries, lymphatic vessels, and prominent sinusoid-like veins. The groove could be demonstrated both macroscopically and histologically in three Bathyergus suillus fetuses of varying sizes. The sinusoid-like veins present in all grooves, regardless of macroscopic shape, suggest that they have a role in the functioning of the groove.

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“…Fermentation rates are presumed equal across ruminants of different sizes and 10-20% of potential food energy is lost through fermentation (Björnhag 1994). Gut capacity in mammals scales with body mass 1 , yet basal metabolic rate scales with body mass 0.75 .…”

Section: Introductionmentioning

confidence: 99%

Harvesting, rumination, digestion, and passage of fruit and leaf diets by a small ruminant, the blue duiker

Wenninger

Shipley

2000

Oecologia

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Because small ruminants (<15 kg) have a high ratio of metabolic rate to fermentation capacity, they are expected to select and require low-fiber, nutrient-dense concentrate diets. However, recent studies suggest that small ruminants may not be as limited in their digestive capacity as previously thought. In this study, we examined harvesting, rumination, digestion, and passage of three diets (domestic figs Ficus carica, fresh alfalfa Medicago sativa, and Pacific willow leaves Salix lasiandra) ranging from 10 to 50% neutral detergent fiber content (NDF) in captive blue duikers (Cephalophus monticola, 4 kg). Harvesting and rumination rates were obtained by observing and videotaping animals on each diet, and digestibility and intake were determined by conducting total collection digestion trials. We estimated mean retention time of liquid and particulate digesta by administering Co-EDTA and forages labelled with YbNO in a pulse dose and monitoring fecal output over 4 days. Duikers harvested and ruminated the fig diet faster than the alfalfa and willow diets. Likewise, they achieved higher dry matter, energy, NDF, and protein digestibility when eating figs, yet achieved a higher daily digestible energy intake on the fresh willow and alfalfa than on the figs by eating proportionately more of these forages. Duikers maintained a positive nitrogen balance on all diets, including figs, which contained only 6.3% crude protein. Mean retention time of cell wall in the duikers' digestive tract declined with increasing NDF and cellulose content of the diet. Digestibility coefficients and mean retention times of these small ruminants were virtually equivalent to those measured for ruminants two orders of magnitude larger, suggesting that they are well adapted for a mixed diet.

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Adaptations in the large intestine allowing small animals to eat fibrous foods

Cited by 38 publications

References 0 publications

The comparative gastrointestinal morphology of five species of muroid rodents found in Saudi Arabia

The comparative gastrointestinal morphology of five species of muroid rodents found in Saudi Arabia

The colonic groove or furrow: A comparative morphological study of six species of African mole‐rats (Rodentia, Bathyergidae)

Harvesting, rumination, digestion, and passage of fruit and leaf diets by a small ruminant, the blue duiker

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