Efficacy of two commercial and indigenous probiotics, Bacillus subtilis and Bacillus licheniformis on growth performance, immuno-physiology and resistance response of juvenile white shrimp (Litopenaeus vannamei)

This study aimed to assess efficacy of commercial and indigenous sources of Bacillus subtilis and Bacillus lichenformis as probiotic dietary supplementation on the growth performance, immuno-physiological variables and resistance response to some stressors in white leg shrimp (Litopenaeus vannamei) weighing 50 +/- 6.54 mg at 28 degrees C for 60 days. Shrimps were fed with four different diets: control (without probiotic); diets supplemented with commercial probiotics(CP) each at 1.5 x 10(6) CFU/g; commercial + indigenous probiotics(CIP) each at 1.5 x 10(6) CFU/g (four strains each at 7.5 x 10(5) CFU/g) and indigenous probiotics (IP) each at 1.5 x 10(6) CFU/g. Growth and feeding parameters including final weight (FW), specific growth rate (SGR) and feed conversion ratio (FCR) were significantly influenced by all probiotics compared to control one (P < .05), with a better growth performance and survival observed in CP group than other treatments. Glucose and cortisol values in all treated shrimps were lower than control one but was only significantly different for CP group (P < .05). Values of albumin, total protein, and lysozyme in CP group was mostly insignificantly higher than other two treated groups, except for lysozyme value that was significantly different (P < .05). In addition, total haemocyte count (THC), large granular cells (LGC), semi-granular cells (SGC) and hyaline cells (HC) significantly increased in CP group compared to other treatments and control but were only significantly different with control one. However, the values of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were significantly lower in all treatment groups compared with control shrimps, except for ALP. Shrimps fed with all types of probiotics showed a higher resistance to environmental stressors including low and high salinities, formalin, chlorine, high and low water temperatures and ammonia but such resistance was more prominent in CP group. The load of Bacillus bacteria in gut of CP treatment was significantly higher than other two groups and control, and that of CIP group was also significantly higher than IP group (P < .05). These data show that there are some differences in efficacy and potency between the commercial and indigenous probiotic sources in growth and health condition of L. vannamei, and thus requires further attention and research works.