Bacillus NP5 Improves Growth Performance and Resistance Against Infectious Myonecrosis Virus in White Shrimp (Litopenaeus vannamei)

Infectious Myonecrosis (IMN) is one of the most prevalent white shrimp diseases. Probiotics are widely used in shrimp cultivation because they have been proven to reduce shrimp disease outbreak. This study aimed to observe the effect of oraly administered probiotic Bacillus NP5 on the white shrimp s growth performance, immune response, and resistance to Infectious Myonecrosis Virus (IMNV) infection. White shrimp Litopenaeus vannamei (2.41±0.07 g individual-1) were fed with a feed supplemented with different doses of the probiotic Bacillus NP5, i.e. 10^2 CFU.g^-1 (A), 10^4 CFU.g^-1 (B), 10^6 CFU.g^-1 (C), and control without any probiotic (negative control, KN; positive control, KP) for 30 days and with three replications for each dose, then KP, treatment A, B, and C were challenged intramuscularly with IMNV (100 μl.shrimp^-1). The results of the study showed that white shrimp fed with the supplemented probiotic had higher Daily Growth Rate (DGR), Feed Conversion Ratio (FCR), and immune response. They also had the higher Total Hemocyte Count (THC) and resistance to IMNV than the positive control. Probiotic with concentration of 106 CFU.g^-1 gave the highest value on enhancing growth, immunity, and resistance of white shrimp towards IMNV infection.