Dietary calcium/phosphorus ratio influences the efficacy of microbial phytase on growth,mineral digestibility and vertebral mineralization in juvenile tiger puffer,Takifugu rubripes |
| |
| Authors: | A LAINING M ISHIKAWA K KYAW J GAO NT BINH S KOSHIO S YAMAGUCHI S YOKOYAMA J KOYAMA |
| |
| Institution: | 1. Science of Marine Resources, The United Graduate School of Agricultural Science, Kagoshima University, Kagoshima, Japan;2. Laboratory of Aquatic Animal Nutrition, Faculty of Fisheries, Kagoshima University, Kagoshima, Japan;3. Education and Research Center for Marine Resources and Environment, Kagoshima University, Kagoshima, Japan |
| |
| Abstract: | A 2 × 3 factorial feeding trial was conducted to determine effects of dietary Ca/P ratio and dietary microbial phytase on growth, mineral digestibility and vertebral mineralization in tiger puffer. The treatments consisted of three levels of Ca/P ratios (0.5, 1.0 and 1.5) combined either with phytase (2000 FTU kg?1 diet) or without supplementation, respectively. The Ca/P ratios were achieved by supplementing calcium at 0, 6 and 12 g kg?1 combined with the same level of inorganic P at 5 g kg?1. After a 50‐day feeding trial, puffer fish fed the diet at low Ca/P ratio (0.5) together with phytase had significantly higher growth rate and feed intake (FI) than other groups. Both dietary Ca/P ratio and phytase supplement were independent effects on plasma minerals and alkaline phosphatase. Interactive effect between both dietary treatments was observed on P and Zn contents in vertebrae and whole body. P and Zn digestibilities tended to increase with increased Ca/P ratio from 0.5 to 1.0, especially when phytase was supplemented. In conclusion, fish fed a diet with highest Ca/P ratio (1.5) showed the poorest growth performance and nutrients utilization. Dietary Ca/P ratio of 0.5 (without Ca supplement) with 2000 FTU phytase per kg would be the optimum combination in the diet of tiger puffer. |
| |
| Keywords: | Ca/P ratio digestibility phytase tiger puffer |
|
|
