Growth Performance, Survival, and Body Composition of Post Larvae of the Freshwater Prawn (Macrobrachium rosenbergil) Fed Graded L-Carnitine Diets

The aim of this study was to investigate the efficacy of L-carnitine incorporated diets on growth, specific growth rate (SGR), feed conversion efficiency (FCE), protein efficiency ratio (PER), survival, and body composition of post larvae of the freshwater prawn Macrobrachium rosenbergii. Five diets containing 0, 0.25, 0.50, 0.75, or 1 g L-carnitine/kg diet were fed to post larvae (0.105+/-0.028 g, 2.21+/-0.13 cm) for thirteen weeks. The highest SGR (3.42+/-0.44%/day), FCE (40.40+/-1.45%), and PER (1.05+/-0.02) were obtained in the 0.50 treatment. The lipid level in the post larvae was inversely related to the L-carnitine level in the diet (p<0.05). The protein level increased with supplementation until the 0.50 level, then decreased with higher levels. Using second-order polynomial regression analysis, the optimal weight gain, SGR, and FCE were obtained with L-carnitine levels of 0.484 g/kg, 0.466 g/kg, and 0.48 g/kg, respectively. In conclusion, 0.50 g L-carnitine per kg feed is optimum for good growth in M. rosenbergii post larvae.