Sites of Organic Acid Production and Pattern of Digesta Movement in the Gastrointestinal Tract of Geese

Clemens, E. T.; Stevens, Charles E.; Southworth, Mary Ross

doi:10.1093/jn/105.10.1341

Cited by 168 publications

(55 citation statements)

References 26 publications

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“…Fatty acid production in caeca has been also reported in domestic fowl and geese (Annison, Hill & Kenworthy, 1968;Clemens, Stevens & Southworth, 1975). This indicates a measure of bacterial food degradation.…”

Section: Introductionmentioning

confidence: 70%

FACTORS DETERMINING GASTkOINTESTINAL TRANSIT TIME OF SEVERAL MARKERS IN THE DOMESTIC FOWL

et al. 1989

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SUMMARYThe aim of this study was to find out how marker characteristics could affect digestive transit time in Gallus gallus. One soluble marker, Cr-EDTA, and two insoluble markers, Cr203 and chromium-mordanted plant cells of two sizes, were used. Three-to six-week-old chickens were killed in series after the oral administration of the markers at intervals of 0, 0 5, 1, 2, 3, 5, 7, and 9 h. The amount of chromium in each digestive segment was determined by atomic absorption. There were some differences in the initial distribution of markers: whereas almost the total amount of the chromium-mordanted rice husk of the largest size was found in the crop at time 0, less than half of the Cr-EDTA was found. Marker emptying out of the crop was fast and not related to either the type or size. In contrast, the emptying rate of the gizzard depended on marker particle size. As far as the caeca were concerned, the ileocaecal junction allowed the passage of soluble Cr-EDTA whereas solid markers were impeded (Cr2O3) or not allowed to pass through at all (vegetable fibre of any size). It can be concluded that marker selection is of major importance to transit time studies in chickens, since its characteristics can determine transit time in an absolute way.

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Section: Introductionmentioning

confidence: 70%

FACTORS DETERMINING GASTkOINTESTINAL TRANSIT TIME OF SEVERAL MARKERS IN THE DOMESTIC FOWL

et al. 1989

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“…For Mallards (Anas platyrhynchos) eating 25-g meals of grains, mean retention times were ϳ5 h, but the esophagus-proventriculus was emptied in 15-45 min (Clark and Gentle 1990). Retrograde movement of portions of digesta (Clemens et al 1975) may retain some fractions while others pass more rapidly, and some shell material may stay in the gizzard longer. Such effects might inflate retention time for the entire meal beyond the time needed for the esophagus-proventriculus to clear for further feeding.…”

Section: Gut Retention Timesmentioning

confidence: 99%

Relative Foraging Value to Lesser Scaup Ducks of Native and Exotic Clams From San Francisco Bay

Richman

Lovvorn

2004

Ecological Applications

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Abstract. Invasions of exotic invertebrates have greatly altered many aquatic communities, but impacts on the foraging energetics of predators seldom have been assessed. In San Francisco Bay, California (USA), a major community change occurred with introduction of the Asian clam (Potamocorbula amurensis) in 1986. This species now greatly outnumbers the previous clam prey of a variety of sharks, rays, sturgeon, flatfish, and crabs, as well as several diving duck species for which the bay is the most important wintering area on the U.S. Pacific Coast. P. amurensis also accumulates much higher levels of some contaminants than the formerly dominant prey. Because alteration of the food base or contaminated foods on wintering areas may be factors in the population decline of scaup ducks, effects of this exotic invasion are important to assess. For Lesser Scaup (Aythya affinis), we studied effects of differences in nutrient content, digestibility, crushing resistance of shells, areal density, size, and depth in the sediments on the relative foraging value of exotic P. amurensis vs. the formerly dominant native clam Macoma balthica. P. amurensis, including shells, had higher nitrogen and energy content per clam of the same length class, and higher digestibility of energy, than M. balthica. Gut retention time did not differ between clam species, so their relative profitability for scaup was determined mainly by the intake rate of digestible nutrients during short, costly dives. For scaup foraging in an aquarium 1.8 m deep, intake rates (number of prey per second) of food items buried in sand-filled trays increased with increasing prey density up to at least 4000 prey/m 2 . For items buried 3 cm deep, intake rates did not differ for prey Ͻ6 mm long vs. prey 6-12 mm long; however, intake rates were much lower when prey were deeper in the sediments (6 cm vs. 3 cm). In the field, a much higher percentage of P. amurensis were in the length range most commonly eaten by Lesser Scaup (Ͻ12 mm), and unlike M. balthica, almost all P. amurensis were in the top 5 cm of sediments where scaup intake rates are highest. In tensometer measurements, shells of P. amurensis were much harder to crush than shells of M. balthica, which might partly offset the apparent energetic advantages of P. amurensis. In many respects, the exotic P. amurensis appears to be a more valuable food than the native M. balthica for Lesser Scaup. However, because P. amurensis accumulates much higher levels of some contaminants, this exotic invasion increases the risk of toxicity to scaup and a range of other benthic predators.

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“…Phenol red (Gon'alons, Rial & Tur, 1983), chromium oxide (Mateos & Sell, 1981), stained particles of feeding stuffs (Sibbald, 1979), polyethylene glycol and several inert particles (Clemens, Stevens & Southworth, 1975;Ferrando, Gonialons & Vergara, 1985) have been used as markers in chickens. The first appearance of the marker in excreta, as detected visually (chromium oxide, stained particles), or by turbidometry (polyethylene glycol), or simple spectrophotometry (phenol red) are the methods most commonly used to evaluate transit time.…”

Section: Introductionmentioning

confidence: 99%

STUDY OF THE RATE OF PASSAGE OF FOOD WITH CHROMIUM‐MORDANTED PLANT CELLS IN CHICKENS (GALLUS GALLUS)

et al. 1987

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SUMMARYThirty broilers 8-10 weeks old were used to study the rate of food passage in chickens. Wheat bran and rice husks of three different sizes: more than 2 mm, between 1 and 15 mm, and less than 0 5 mm, mordanted with chromium, were used as markers. The suitability ofthese markers to study the rate of food passage in chickens and the possible influence of the size and hardness of the particle on the retention time was the objective of this study. Both T1, the time of first appearance of the marker, and Tm, the mean retention time, have been evaluated. Tm was a better parameter than T1 for studying transit time. Tm was longer with the biggest particles, especially with rice husk. The gizzard, with its grinding activity and pylorus, a selector ofparticle size, seems to be the transit regulator for solid particles in chickens. No chromium was found in the caecal contents of any case.

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Sites of Organic Acid Production and Pattern of Digesta Movement in the Gastrointestinal Tract of Geese

Cited by 168 publications

References 26 publications

FACTORS DETERMINING GASTkOINTESTINAL TRANSIT TIME OF SEVERAL MARKERS IN THE DOMESTIC FOWL

FACTORS DETERMINING GASTkOINTESTINAL TRANSIT TIME OF SEVERAL MARKERS IN THE DOMESTIC FOWL

Relative Foraging Value to Lesser Scaup Ducks of Native and Exotic Clams From San Francisco Bay

STUDY OF THE RATE OF PASSAGE OF FOOD WITH CHROMIUM‐MORDANTED PLANT CELLS IN CHICKENS (GALLUS GALLUS)

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