| Abstrakt: |
AbstractChannel catfish Ictalurus punctatus(weight, 320–420 g) were fed diets with 100 or 1,000 mg ascorbic acid/kg of diet for 7 weeks in ponds. Anterior kidney neutrophil function was assessed by incubating the neutrophils with Edwardsiella ictaluri. Percent phagocytosis, phagocytic index (the mean number of bacteria phagocytized per cell by all neutrophils, including nonphagocytic ones), and bactericidal capabilities of the anterior kidney neutrophils were measured at 0, 90, 180, 270, and 360 min. Serum cortisol was also measured. No significant difference was observed between the two diets with respect to anterior kidney neutrophil function or serum cortisol levels. However, serum cortisol levels did affect mean phagocytic index of anterior kidney neutrophils. Catfish that had serum cortisol levels greater than 10 μg/dL displayed a significant decrease in the phagocytic index when compared with catfish that had cortisol levels less than 5 μg/dL. |
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