2006 Volume 54 Issue 3 Pages 391-398
The present study investigated the efficacy of phytase with graded level of dietary phosphorus (P) on improvement of nutrient availability in soybean meal containing diet for Japanese flounder. Experimental diets where P sources were omitted from the mineral mixture, and graded level of inorganic P (0, 200, 400, 600 and 800 mg / 100 g diet) with phytase (300 FTU / 100 g diet) were assigned in duplicate tanks and fed to juvenile Japanese flounder (average weight 9 g) for 40 days. Supplementation of phytase into the diet significantly improved protein and P absorbability compared to control diet. Growth parameters and P retentions improved in fish fed diet Phytase and P supplementations. Among the dietary treatments, P supplement level of 400 mg was the best P retention. The results indicated that phytase with 400 mg P supplemented diet significantly improved the weight gain and minerals availability comparing to control. These findings lead to reduce the excess supplementation inorganic P addition in diet and finally the P discharge into the environment.