From June to August, the growth experiment was conducted in a recirculating rearing system on juvenile of the southern catfish, Silurus meridionalis Chen with initial weight 12.93 +/- 0.13g. The white fishmeal, corn oil and gelatinized cornstarch were used as protein, lipid and carbohydrate respectively. Fish were fed with six iso-nitrogenous (40%crude protein) and iso-lipidic (10% crude lipid) experimental diets contain 0(control diet) 6, 12, 18,24 and 30% of carbohydrate level. At each of the diets, 4 groups of southern catfish ( 12 in each group) were fed at ad libitum ration level for 8 weeks at 27.5 degrees C. The digestibility of carbohydrate was not significantly affected when dietary carbohydrate level did not exceed 18% but decreased when dietary carbohydrate level exceeded 18%. The feeding rate and specific growth rate (SGR) increased with dietary carbohydrate level at a level of dietary carbohydrate not more than 18%, and decreased at a higher level. The feeding rate of 6% and 12% carbohydrate level were significantly higher than those of other levels, and the feeding rate of 30% carbohydrate level was significantly lower than those of other levels. The specific growth rate (SGR) of 6% and 12% carbohydrate level were significantly higher than those of 0, 24 and 30% carbohydrate levels, and specific growth rate ( SGR) of 30 % carbohydrate level was significantly lower than those of 6, 12, 18 and 24 % carbohydrate level. The results suggested the optimal dietary carbohydrate level for growth in this fish was 12%-18%.
Fu Shi-Jian (firstname.lastname@example.org) ; Xie Xiao-Jun (email@example.com).Effect of dietary carbohydrate levels on growth performance in Silurus meridionalis Chen,Acta Hydrobiologica Sinica,2005,29(4):393-398