Effect of different dietary protein and water salinity on the growth performance, feeding indices and carcass composition of Litopenaeus vannamei

The effect of different dietary protein and salinity levels were evaluated on growth performances, feeding indices and carcass biochemical composition of the Litopenaeus vannamei. 350 shrimp with the initial average weight of 5.55±0.18 g and length of 8.81±0.15 cm were distributed randomly into 27 concrete experimental tanks. A 3×3 factorial experiment including three levels of salinity (0-3, 12-15 and 32-35 ppt) and three levels of dietary protein (25, 35 and 45%) was carried out for a period of 56 days. Experimental shrimps were fed at satiation 4 times a day throughout the experimental period. Based on the results, the highest indices of growth were observed in all the salinity levels in the experimental treatments fed diet containing 35% dietary protein. However, the highest body weight gain and specific growth rate were recorded at the highest levels of salinity (35-32 ppt). The best feeding indices were observed at the highest level of dietary protein and water salinity. No significant difference was observed in morphometric indices among different experimental treatments. The results of the body biochemical composition showed no significant difference in protein, ash and moisture content among treatments. However, higher lipid content was significantly observed in treatments with higher salinity and protein levels. Based on the results of this study, the economic point of view part of the protein diet with the 35% is suggested for L. vannamei cultured in 32-35 ppt salinity.