Interactions of L-Ascorbyl-2-Phosphate Mg and Oxidized Fish Oil on Red Sea Bream Juveniles

A 2×3 factorial experiment was conducted using two degrees of oxidation of the 10% supplemental fish oils in the diet [fresh oil, peroxide value 17 meq/kg (FO)and oxidized oil, peroxide value 256meq/kg (XO)], three levels of supplementalL-ascorbyl-2-phosphate-Mg (APM) 0, 50 and 500mg/100g diet on red sea bream Pagrus major juveniles (initial body weight_??_3.36g). The fish grew 9-10 fold over a 60 days period of feeding in the groups of APM-supplemented with fresh or oxidized oil (50-FO, 50-XO, 500-FO and 500-XO) and showed better performance (weight gain, feed conversionefficiency, specific growth rate, survival), body condition (condition factor, hepatosomatic index, collagen content of bone), and biochemical parameters (tissue ascorbic acid and thiobarbituric acid value(TBA value) thanthe groups of APM-unsupplemented (0-FO and 0-X0). However, the analysis of variancerevealed that there was significant (p<0.05) interaction of APM-level andoil-type in the tissues ascorbic acid level and condition factor. APM had strong main effect on all variables whereas oil type hadnot. A depletion of APM from the diets (0-FO and 0-XO) resulted in accelerating lipid peroxidation ofmuscle measured as TBA value and low lipid accumulation as triglyceride in muscle and liver.