Research
| Title： | Quantifying the dietary potassium requirement of subadult grass carp (Ctenopharyngodon idellus) |
|---|---|
| First author： | Chen, C.; Zhu, W.; Wu, F.; Liu, M.; Tan, Q.; Han, D.; Xie, S.; Liang, X. |
| Journal： | AQUACULTURE NUTRITION |
| Years： | 2016 |
| DOI： | 10.1111/anu.12279 |
| Abstract： | A growth trial lasting for 12 weeks was conducted in 21 net cages to determine the dietary potassium (K) requirement of subadult grass carp (Ctenopharyngodon idellus) (Average weight: 331.3 g). Seven isonitrogenous and isoenergetic semi-purified diets were compounded with different dietary K level. The specific growth rate (SGR) of fish was significantly (P < 0.05) improved by dietary K supplementation, SGR and the gill Na+-K+ ATPase activity increased first and then decreased (P < 0.05) as dietary K level increased. The highest SGR and gill Na+-K+ ATPase activity values were both observed at 6.38 g kg(-1) group. Dietary K level showed significant (P < 0.05) effect on serum superoxide dismutase (SOD) and glucose (GLU), the maximum values of SOD and GLU were in 8.42 and 6.38 g kg(-1) group, respectively. The body lipid content of the 6.38 g kg(-1) group was significantly (P < 0.05) lower than that of the control. However, the ash content in the 8.42 g kg(-1) group was significantly higher than those in the 1.21, 2.21, 4.41 and 6.38 g kg(-1) group. When dietary protein was 320 g kg(-1) and the waterborne potassium ranged from 6.86 to 9.10 mg L-1, the dietary K requirement for subadult grass carp judged from SGR and gill Na+-K+ ATPase activity is 5.38 and 7.41 g kg(-1) diet, respectively. |
