Effects of dietary supplementation of Bacti-nil®Aqua on growth performance, feed utilization, immune responses, and body composition of the Pacific white shrimp, Litopenaeus vannamei

This study aimed to evaluate the dietary supplementation of various levels of Bacti-nil®Aqua on growth performance, nutrient utilization, immune response, antioxidant activities, mortality rate, and chemical composition of the Pacific white shrimp < em> Litopenaeus vannamei. Four hundred and eighty L. vannamei fries (3.0 ± 0.002 g) were randomly divided into 4 treatments (T1-T4). T1 represented the negative control fed on a basal diet, the fries in treatments T2, T3 and T4 were fed on Bacti-nil®Aqua supplemented diet at three concentrations of 2, 3, and 4g/kg diet, respectively, for 60 days. The results showed that the morphometrics measurements (body and antenna length), the growth parameters (BW, BWG, ADG, and RGR) and the condition factor values were significantly (P < 0.05) higher in the Bacti-nil®Aqua supplemented treatments than those of the control group. Moreover, the different Bacti-nil®Aqua supplemented diets had no significant effect on the survival rate (SR) of L. vannamei. The chemical composition of the L. vannamei and feed utilization parameters exhibited no significant differences in DM and ash. The protein content of L. vannamei increased significantly when fed on Bacti-nil®Aqua, compared to T1.  In contrast, the highest values of lipids were recorded in the control treatment (T1). Different concentrations of Bacti-nil®Aqua (T2-T4) resulted in a significant improvement in PER and PPV%, the best FCR, and the highest nonspecific immune responses (THC, phagocytosis, lysozyme activity, and phenoloxidase activity), in addition, superoxide dismutase activity compared to the control diet (T1). Overall, the current study concluded that the highest levels of Bacti-nil®Aqua (3 and 4g/kg) resulted in improved growth parameters, survival rate, feed utilization, chemical composition, and nonspecific immune responses of L. vannamei.