| Abstrakt: |
The development ofa pathological condition in the distal intestine of Atlantic salmon, Salmo salar L., induced by dietary soybean meal, v/as studied in a 6-week feeding experiment. The fully developed condition, as observed after 3 weeks on the experimental diets, was characterized by: (1) a shortening of heights ofthe mucosal foldings; (2) a loss ofthe normal supranuclcar vacuolization of the absorptive cells in the intestinal epithelium; {3} a widening of the central stroma within the mucosal foldings, with increased amounts of connective tissue; and (4) a profound infiltration of inflammatory cells in the lamina propria. The first signs of morphological changes were observed after 2 days on a diet containing a solvent extracted soybean meal, and within 7 days, all the above mentioned signs were observed. When the fish were subsequently transferred to a control diet, the mucosal folds were rebuilt from the base, resulting in an apparently functional epithelium after 3 weeks. Starved fish also exhibited characteristic changes of the mucosa, including a finely granular cytoplasm replacing the supranuclear vacuoles seen in the epithelial cells of normal fish. In addition, a pattern of irregularly spaced indentations developed in the epithelium of the simple folds. The condition induced by dietary soybean meal was classified as a non-infectious subacute enteritis, and a pathogenesis involving immunological mechanisms is suggested. [ABSTRACT FROM AUTHOR] |
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