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

Abstract

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), sur- vival, 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 con- clusion, 0.50 g L-carnitine per kg feed is optimum for good growth in M. rosenbergii post larvae.