Biological, nutritional, and hematoimmune response in juvenile Cherax quadricarinatus (Decapoda: Parastacidae) fed with probiotic mixture

Objective. To evaluate the effect on biological, nutritional, and hematoimmune indicators of juvenile Cherax quadricarinatus were cultivated and fed with a probiotic mixture. Materials and methods. A completely randomized design (DCA) with six treatments: 0 (control), 1×102 μL, 2×102 μL, 3×102 μL, 4×102 μL and 5×102 μL of a probiotic mixture (Bacterol Shrimp Forte), with three repetitions each, 18 experimental tanks of diameter 1.7 m and area of 2.26 m2 were used, with a density of 20 juveniles (0.95 ± 0.10g and 7.78 ± 0.77mm) per tank for 60 days. Biological (weight, length, weight gain, weight increase, specific growth rate, length gain, length increase and survival), nutritional (feed conversion, feed efficiency and protein efficiency rate) and hematoimmune (total of hemocytes, differential hemocytes, phagocytic rate, superoxide dismutase and hypoxic stress) parameters were measured. Results. For biological indicators, the best results (p<0.05) were obtained when using 4×102 μL of the probiotic (final weight: 9.11 g; final length: 68.95 mm; specific growth rate: 3.74). Regarding the nutritional parameters, the best results were found with for 3×102 μL (feed conversion: 1.09, feed efficiency: 0.91, and protein efficiency: 2.61); although there were no differences between 3×102 and 4×102 μL. For the hematoimmune response, there were differences (p<0.05) for all the indicators under study, with a better performance for 4×102 μL of the probiotic mixture. Conclusions. The probiotic mixture induces the hematoimmune, biological, and nutritional response with the best response for concentrations of 3×102 μL, 4×102 μL.