Gastrointestinal physiology and nutrition in wild birds

Duke, Gary E.

doi:10.1079/pns19970109

Cited by 67 publications

(72 citation statements)

References 21 publications

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“…It is more difficult to judge the extent of food lipid conservation. Indeed, regular refluxes from the duodenum into the stomach are a peculiarity of avian digestion and it is therefore likely that stomach contents are exposed to pancreatic and duodenal lipases (Duke, 1997). In the hypothesis of passage of some pancreatic enzymes from the duodenum to the stomach via refluxes, the pH of about 6 monitored in incubating penguins would allow these lipases to be active.…”

Section: Gastric Phmentioning

confidence: 99%

Adjustments of gastric pH, motility and temperature during long-term preservation of stomach contents in free-ranging incubating king penguins

Thouzeau

Peters

Bohec

et al. 2004

Journal of Experimental Biology

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Male king penguins are able to store undigested food in their stomach for up to 3 weeks during their incubation fast, which evidently implies some modification of their digestive process. Using small electronic recorders, we studied the change in gastric pH, motility and temperature during the first week of food storage. The pH could be maintained at values as high as 6 throughout the incubation fast, a pH that is unfavourable for avian gastric proteinase activity. Gastric motility was never completely inhibited but could be markedly reduced. Stomach temperature was maintained at around 38°C.The fact that stomach temperature of incubating birds did not show a daily rhythmic fluctuation as seen in nonbreeding birds could be due to temperature constraints on embryo development. Thus the present study demonstrates substantial adjustments of pH and gastric motility in incubating king penguins, which may contribute to the inhibition of digestive gastric processes.

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Section: Gastric Phmentioning

confidence: 99%

Adjustments of gastric pH, motility and temperature during long-term preservation of stomach contents in free-ranging incubating king penguins

Thouzeau

Peters

Bohec

et al. 2004

Journal of Experimental Biology

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“…The glandular stomach (proventriculus) varies in size between species, being relatively small in graminivores but often quite large and distensible in carnivores that ingest large food items (Duke, 1997). In the black-winged kite (Elanus caeruleus), the stomach found large in size and Asian J.…”

Section: Introductionmentioning

confidence: 99%

Histomorphological and Histochemical Studies of the Stomach of the Mallard (Anas platyrhynchos)

Al-Saffar¹,

Al-Samawy²

2015

Asian J. of Animal Sciences

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The study aimed to find out the histomorphological and histochemical structures of the walls of the stomach parts in mallard. To conduct this investigation, twelve healthy birds were collected from local suppliers at Baghdad province. Later on, birds were subdivided into three equal subdivisions, each of four for gross, histological and histochemical approaches. All birds were anesthetized and their abdomens were dissected, then their stomach were identified and photographed in situ. Organs were grossly described and specimens were immersed either in 10% neutral buffered formalin or in Bouin's solution for histological fixation and then processed for histological and histochemical staining techniques, which were comprised Hematoxylin-eosin, Masson Trichrome, Periodic Acid Schiff (PAS) and PAS-Alcian Blue (AB) (pH 2.5). The gross findings showed that the stomach was consisted of two distinguishable chambers, that were proventriculus and ventriculus. The proventriculus was tubular-shaped organ. The ventriculus appeared fusiform in shape and covered by thin fatty tissue. There was well demarcation between proventriculus and ventriculus. Histologically, the proventriculus mucosa lining was simple columnar epithelium. The submucosal consists of numerous and voluminous deep submucosal glands. The covering of the ventriculus was simple cuboidal. Presence of thick cuticle layer with well-developed muscular stomach. Muscularis mucosa appeared characteristically thick layer of smooth muscle bundles arranged as, inner circular and outer longitudinal layers. The tunica muscularis appeared, as a very thick structure of smooth muscles fibers. Three layers of muscles were distinguished that were thin inner, outer longitudinal and very thick intermediate circular layers.

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“…Total organic carbon and saccharides decrease along the alimentary canal, indicating that organic compounds are utilized by microorganisms during gut passage. However, organic compounds likely are subject to assimilation by the earthworm, since (i) long-chain fatty acids derived from ingested bacteria can be assimilated into earthworm tissue (46), and (ii) the capacity to assimilate organic molecules in the gastrointestinal tract is a general trait of animals (3,13,16,23,43,60). Thus, it is very likely that fermenters, denitrifiers, and the earthworm compete for available carbon.…”

mentioning

confidence: 99%

In Situ Hydrogen and Nitrous Oxide as Indicators of Concomitant Fermentation and Denitrification in the Alimentary Canal of the EarthwormLumbricus terrestris

Wüst

Horn

Drake

2009

Appl Environ Microbiol

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The earthworm gut is a unique microzone in aerated soils that has been proposed to selectively stimulate ingested soil microorganisms by its in situ conditions, which include anoxia, high water content, a near-neutral pH, and high concentrations of organic compounds. The central objective of this study was to resolve potential links between in situ conditions and anaerobic microbial activities during the gut passage of Lumbricus terrestris. Both H 2 and N 2 O were emitted by living earthworms, and in situ microsensor analyses revealed both H 2 and N 2 O in the O 2 -free gut center. The highest H 2 concentrations occurred in foregut and midgut regions, whereas the highest N 2 O concentrations occurred in crop/gizzard and hindgut regions. Thus, H 2 -producing fermentations were more localized in the foregut and midgut, whereas denitrification was more localized in the crop/gizzard and hindgut. Moisture content, total carbon, and total nitrogen were highest in the foregut and decreased from the anterior to posterior end of the gut. Nitrite, ammonium, and iron(II) concentrations were highest in the crop/gizzard and decreased from the anterior to posterior end of the alimentary canal. Concentrations of soluble organic compounds were indicative of distinct fermentation processes along the alimentary canal, with maximal concentrations of organic acids (e.g., acetate and butyrate) occurring in the midgut. These findings suggest that earthworms (i) contribute to the terrestrial cycling of carbon and nitrogen via anaerobic microbial activities in the alimentary canal and (ii) constitute a mobile source of reductant (i.e., emitted H 2 ) for microbiota in aerated soils.Earthworms constitute the dominant soil macrofauna in many soils (15,34,36) and emit the greenhouse gas nitrous oxide (N 2 O) concomitantly with molecular nitrogen (N 2 ) via denitrifying bacteria in the gut (10,11,24,26,30,39). The in situ conditions of the earthworm gut, which include anoxia, high water content, a near-neutral pH, and high concentrations of organic compounds, may activate certain ingested soil bacteria, in particular bacteria capable of anaerobiosis (10, 11, 27, 28-30, 33, 62). In this regard, the numbers of cultured anaerobes and denitrifiers are two to three orders of magnitude greater in the earthworm gut than in soil (28-30), and the amount of bacterial long-chain fatty acids is higher in the gut than in soil (46).Gut contents of earthworms contain up to 80% intestinal mucus (i.e., up to 0.8 g mucus per g [dry weight] gut content) that consists of monosaccharides, low-molecular-weight amino acids, and glycoproteins (5,37,42,62). This large amount of degradable organic carbon in the anoxic gut suggests that fermentation is very active during gut passage (27). Indeed, fermentative bacteria are abundant in the gut of earthworms (25,28,30). Nitrate reducers also are abundant in the earthworm gut (28) and can produce fermentation products when nitrate is not available (58). Many fermentative or facultative microorganisms also can reduce nit...

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Gastrointestinal physiology and nutrition in wild birds

Cited by 67 publications

References 21 publications

Adjustments of gastric pH, motility and temperature during long-term preservation of stomach contents in free-ranging incubating king penguins

Adjustments of gastric pH, motility and temperature during long-term preservation of stomach contents in free-ranging incubating king penguins

Histomorphological and Histochemical Studies of the Stomach of the Mallard (Anas platyrhynchos)

In Situ Hydrogen and Nitrous Oxide as Indicators of Concomitant Fermentation and Denitrification in the Alimentary Canal of the EarthwormLumbricus terrestris

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