An investigation on determination of different levels of dietary supplemental L-carnitine and lipid on growth performance and body chemical composition of gilthead sea bream (Sparus aurata)

Two different experiments were carried out in this study. 1st experiment dealt withthe effect of different L-carnitine levels (0, 1, 2, 3 ve 4g/kg diet; G0, G1, G2, G3 ve G4respectively) on growth performance and proximate composition of sea bream. The fish(5.29±0.97 g) were grown on experimental diets for 45 days in three replicates. The resultsshowed that higher growth, weigth gain and feed efficiency were displayed by G3 and G4than the other groups (P<0.05). The utilization of fatty acids in fish liver and muscles weremore effective in the same experimental groups than the other groups, and also,triacylglyserol (TAG), which is used for energy production, rose with L-carnitine levels. Inthe 2nd experiment, sea bream (4.04±0.01 g) were fed for 43 days with prepared dietscontaining two different lipid (12.5 and 20%) and three different L-carnitine level (0, 2 and3 g/kg diet) combinations. This experiment was undertaken to investigate the effects ofgrowth performance and proximate composition of graded dietary lipid and L-carnitinelevels in sea bream. According to the results, there were no effects of lipid and L-cartnitinesupplementation as well as interaction of both factors on growth or lipid composition of thefish (p>0.05). On the other hand, whole body composition results showed slight differenciesbetween the initial and final protein composition of the fish. There was no clear effects oflipid or L-carnitine on fatty acid composition of the fish. In contrast, TAG and free fattyacids (FFA) results indicated that L-carnitine and lipid levels were affected in the fish liverand muscles. These neutral lipid classes were used more effectively when the lipid levels ofthe diets was increased.Key Words: Sparus aurata,L-carnitine, lipid, fatty acids, neutral lipid classes.