Dietary supplementations of Bacillus probiotic improve digestibility, growth performance, innate immunity, and water ammonia level for Pacific white shrimp, Litopenaeus vannamei

This study was conducted to evaluate the dietary supplementation of two Bacillus spp. on digestibility, growth performance, innate immunity, and water ammonia level of Litopenaeus vannamei. A control diet was made without the probiotic supplementation, and four other diets were prepared by including B. subtilis (BS) alone (0.1 × 10¹⁰ and 0.2 × 10¹⁰) or a mixture of BS and B. pumilus (BP) (0.1 × 10¹⁰ and 0.2 × 10¹⁰). Quadruplicate groups of shrimp (0.14 g) were hand-fed one of the diets for 8 weeks. Shrimp fed diets containing Bacillus spp. showed significantly higher apparent digestibility coefficient of protein and dry matter than shrimp fed the control diet. The growth performance was significantly improved in shrimp fed higher dose (0.2 × 10¹⁰) of the Bacillus spp. compared to the control group. Innate immunity of shrimp fed the probiotic diets was significantly enhanced compared to the control group. In a water ammonia test, culture water of the probiotic diets had lower total ammonia concentration than that of the control diet. The results in this study suggest that Bacillus spp. can positively affect digestibility, growth performance, feed efficiency, innate immunity, and water quality for L. vannamei.