Effect of direct injection of shark DNA into skeletal muscles on the productive performance characteristics of red tilapia (Oreochromis sp.) fed at different dietary regimes

The present work aims to study the effect of direct injection of shark ( Squalus acanthias L.) DNA into skeletal muscles of red tilapia ( Oreochromis sp.) fingerlings fed at different dietary regimes (three protein levels; 18, 22 and 26% each with two metabolizable energy levels; 244 and 260 kcal/100 g diet) on the productive performance. The results showed that growth performance, body composition and feed utilization of red tilapia injected with shark DNA had significant superiority (P ≤0.05) compared with non-injected fish. Red tilapia fed 22% protein diet had significant improving (P ≤0.05) most of the productive performance traits. Moreover, final body weight, weight gain, percent body weight increases, feed intake and protein retention percentage of red tilapia fed on diet containing 244 kcal/100 g, were significantly higher (P ≤0.05) than those of fish fed on diet containing 260 kcal/100 g. These data suggests that dietary protein can be spared down to 22% protein by direct injection of shark DNA into skeletal muscles of fish. Thus, feed costs can be reduced by a further reduction in dietary protein. Therefore, the result of the present work indicates a possible easy and rapid way for improving fish characteristics.