Influence of different dietary carbohydrates levels on some nutritional physiological parameters and selenium metabolism in nile-catfish [clarious lazara]

ABSTRACT

Effect of dietary carbohydrate [CHO] on hematology, blood chemistry, hormone and immunity was studied in Nile catfish. Nonsignificant decrease in body weight and growth of catfish fed high levels of CHO and no significant decrease in Hb and HCT% were observed. Concerning serum cortisol, glucose and cholesterol had a positive correlation with increase of CHO in diet. On the other hand, serum calcium, phosphorus, total protein and immunoglobulin M [IgM] were negatively correlated with dietary levels of CHO. Catfish reared on high CHO diet with 10 Ug selenium per gram diet had a significantly high liver and kidney selenium content than those reared on selenium free CHO after six weeks, indicating that excess dietary CHO enhances dietary selenium toxicity. In addition, liver copper levels were significantly affected with increased incidence of renal calcinosis, suggesting a variety of toxic effects of selenium on catfish