Dietary calcium requirement and effects on growth and tissue calcium content of juvenile grass carp (Ctenopharyngodon idella) |
| |
Authors: | J.‐J. LIANG Y.‐J. LIU Z.‐N. YANG L.‐X. TIAN H.‐J. YANG G.‐Y. LIANG |
| |
Affiliation: | 1. Nutrition Laboratory, Institute of Aquatic Economic Animals, School of Life Science, Sun Yat‐Sen University, Guangzhou, China;2. Shihai Feed Co., Ltd., Zhuhai, China |
| |
Abstract: | A growth trial was conducted to estimate the optimum concentration of dietary calcium (Ca) for grass carp (Ctenopharyngodon idella). Triplicate groups of grass carp (4.52 ± 0.02 g) were fed diets containing graded levels (2.75, 4.51, 6.24, 7.99, 9.66 and 11.5 g kg?1) of Ca for 8 weeks. Weight gain, feed efficiency and protein efficiency ratio were linearly increased up to the 7.99 g kg?1 dietary Ca and then maintained stable beyond this level (P < 0.05). Dietary Ca levels higher than 7.99 g kg?1 significantly increased the ash contents of whole body, vertebrae and scales. Ca contents in whole body, vertebrae and scales were linearly increased up to the 7.99 g kg?1 dietary Ca and then maintained stable beyond this level (P < 0.05). In contrast, dietary Ca levels higher than 9.66 g kg?1 significantly decreased Mg contents in whole body, vertebrae and scales. Dietary Ca levels higher than 7.99 g kg?1 significantly increased plasma alkaline phosphatase activity. However, plasma Ca, P and Mg contents were not significantly affected by dietary Ca supplements (P > 0.05). Polynomial regression analysis indicated that 10.4 g kg?1 dietary Ca was required for maximal tissue storage and mineralization as well as optimal growth. |
| |
Keywords: | calcium requirement diet grass carp (Ctenopharyngodon idella) growth performance mineralization plasma alkaline phosphatase activity |
|
|