Effects of Dietary Calcium Levels on Growth Performance, Blood Biochemistry and Whole Body Composition in Juvenile Bighead Carp (Aristichthys nobilis)

Özet

An eight weeks feeding experiment was conducted to investigate the effects of dietary calcium (Ca) levels on growth performance, blood biochemistry and whole body composition in bighead carp (105.52 ±0.33g; 16.91±0.09cm). Six practical diets (31.0% crude protein, 6.0% crude lipid) were formulated to contain graded Ca levels ranging from 0.41% to 1.59% of dry diet. At the end of the feeding trial, results showed that survival rate (SR) was not significantly affected by dietary Ca level. Final weight (FW), weight gain (WG), specific growth rate (SGR) increased with the increasing dietary Ca level up to 1.26%, and thereafter showed a decreasing trend, while feed conversion ratio (FCR) showed a converse trend. Furthermore, high Ca level (1.59%) significantly increased the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and significantly decreased serum phosphorus (P) content (P 0.05). Based on FCR and SGR, the optimal dietary Ca level was determined to be 1.26%, and the corresponding Ca/ P ratio was calculated to be 1.13:1.