Quantification of vitamin C requirement for juvenile hybrid tilapia, Oreochromis niloticus X Oreochromis aureus, with L-ascorbyl-2-monophosphate-Na and L-ascorbyl-2-monophosphate-Mg.

摘要

A growth experiment was conducted to quantify the level of L-ascorbyl-2-monophosphate-Na (C2MP-Na) to satisfy the dietary ascorbic acid requirement for juvenile O. niloticus X O. aureus hybrids. L-Ascorbyl-2-monophosphate-Mg (C2MP-Mg) was also included in the study for comparison. Purified diets with 6 levels of ascorbic acid (0, 30, 50, 70, 90 and 120 mg/kg diet) from supplemental C2MP-Na or C2MP-Mg were each fed to triplicate groups of fish (initial weight 1.22 g) for 8 weeks. Fish fed on C2MP-Na>=38.97 mg/kg diet and C2MP-Mg >=22.92 mg/kg diet gained (P<0.05) more body weight than fish fed on the unsupplemented diet. Hepatic ascorbate concentrations in fish generally increased as the dietary ascorbate level increased. Results of broken line analysis indicated that the adequate dietary ascorbic acid from each source for growing fish is C2MP-Na 63.4 mg/kg (equivalent to 15.98 mg of ascorbic acid/kg) diet and C2MP-Mg 40.5 mg/kg (equivalent to 18.82 mg ascorbic acid/kg) diet, and it also indicatedthat C2MP-Mg was about 85% as effective as C2MP-Na in meeting the ascorbic acid requirement for O. niloticus X O. aureus.