Abstract
Common carp Cyprinus carpio is a major commercial farmed species which has been cultivated widely in Syria. However, no previous studies focused on appropriate dietary protein levels for this fish species. The present study aimed at estimating the effect of different dietary protein levels on the growth performance and biochemical composition of common carp, Cyprinus carpio cultured in cement ponds. Three experimental diets were formulated with different protein content, T1 (22.4%), T2 (29.9%) and T3 (36.3%). Nine cement ponds were prepared with three ponds for each treatment, in each of which fifty fingerlings were placed. Fingerlings of initial weight of (42.3±1.24) g for (T1), (41.5±1.22) g for (T2) and (42.5±0.4) for (T3), were fed twice a day for five months. Weight gain (WG), Food Conversation Ratio (FCR), Daily Weight Gain (DWG), Specific Growth Ratio (SGR) and Survival Rate were assessed. Biochemical composition: protein, fat, ash and moisture contents of the experimental diets and of fish meat were also determined. Results showed that (T3) was the best diet with DWG of (2.64±0.15), WG of (396.35±15.07g) and a protein content in fish meat of (17.1±0.4%). Moreover, FCR value of (2.12±0.008) in (T3) compared to (2.21±0.03) and (2.95±0.1) recorded in (T2) and (T1) respectively.