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

¹ Unit of Physiology, Department of Cellular Biology and Physiology, Veterinary Faculty, Universidad Autonoma de Barcelona, Bellaterra, 08193 Barcelona, Spain

The 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, Cr₂O₃ 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.

This article has been cited by other articles:

				C. Thouzeau, G. Peters, C. Le Bohec, and Y. Le Maho Adjustments of gastric pH, motility and temperature during long-term preservation of stomach contents in free-ranging incubating king penguins J. Exp. Biol., July 1, 2004; 207(15): 2715 - 2724. [Abstract] [Full Text] [PDF]