CARNITINE - A VITAMIN FOR RAINBOW-TROUT

The effects of L-carnitine (0 vs. 450 mg added L-carnitine/kg diet) wi th different dietary levels of L-lysine (4.7 vs. 5.3 g Lys/16 g N) and sulphur amino acids (3.2 vs. 3.5 g Met + Cys/16 g N) on growth and fe ed efficiency were studied over 84 days in a total of 480 rainbow trou t fingerlings (Oncorhynchus mykiss) with a mean body weight of 20 g pe r fish. In fish receiving diets marginally deficient in lysine and met hionine, L-carnitine improved specific growth rate (+ 4%) and feed eff iciency (+ 8%) significantly (P < 0.05). The effect of carnitine on bo dy weight, weight gain and feed consumption was not significant. It is suggested that the lysine-sparing effect of carnitine can be traced b ack to metabolic effects of lysine on carnitine transport across membr anes.