Aims: Efforts to reduce the feed conversion ratio, increase the rate of growth, and increase resistance to diseases are among the most important purposes of research on carp common carp. The aim of this study was to examine the effect of different levels of L-carnitine on growth factors, body compositions, and some blood biochemical parameters of fingerling carp (Cyprinus carpio).
Materials and Methods: The present experimental research was conducted on 90 fish for 8 weeks. The fish were randomly divided into 9 fiberglass tanks containing 300liters in 3 treatments and 3 replicates. Treatments consisted of 3 levels (0, 500, and 1000mg L-carnitine) and the fish were fed 3 times a day. Growth, morphometric, and nutritional parameters, as well as blood factors of the treatments were compared. The value of moisture, ash, protein, and fat in diet and body composition were determined by AOAC method; the data were analyzed by SPSS 16 software, using one-way ANOVA and Duncan test.
Findings: Different amounts of L-carnitine showed no significant difference in growth, but with increasing the levels of L-carnitine, an increasing trend was observed in improving feed conversion ratio. Value of protein and fat of body composition were increased and decreased, respectively, by 1000mg that was statistically different from the control group (p<0.05). Value of glucose and HDL increased and cholesterol and LDL decreased by 1000mg L-carnitine compared with the control group (p<0.05). L-carnitine had no significant effect on the level of triglyceride and hematocrit.
Conclusion: The addition of 1000mg L- carnitine/kg to common carp fingerlings diet improves the body composition and the function of blood parameters in the treated fish.