Neeraja, T (MAJOR)Haribabu, PRamalingaiah, DLOKESH, B2021-07-142021-07-142018-11https://krishikosh.egranth.ac.in/handle/1/5810170526THESESA study was carried out to evaluate the effect of adding three levels of garlic powder and tamarind pulp powder at 0.1, 0.5 and 1.0% in a basal diet (commercial pellet feed) of Pacific white shrimp, Litopenaeus vannamei juveniles (5.51±0.34 g) on growth performance, survival rate, haematological and immunological parameters. This study also evaluated the utilization of garlic powder and tamarind pulp powder in the diets of L. vannamei as antibacterial agent against vibrio harveyi infection. The experiment was carried out for 49 days as two set ups. In experimental set up-1, L. vannamei were fed on four experimental diets with 0% (G0), 0.1% (G1), 0.5% (G2) and 1.0% (G3) of garlic powder in basal diet. Similarly, experimental set up-2 consisted of four experimental diets with 0% (T0), 0.1% (T1), 0.5% (T2) and 1.0% (T3) of tamarind pulp powder in basal diet. After 49 days of feeding trial, shrimp were challenged with vibrio harveyi by intramuscular injectionand observed for 72 hrs at every 12 hrs interval, to determine survival rate. The dietary garlic and tamarind pulp powder inclusion at three different levels had significantly (p 0.05) different between T2 and T3. Survival rate was not significantly different among T2, T3 and T1. After the feeding trial, shrimp fed with different doses of the garlic and tamarind diets had higher survival rates compared to the controls from 12-72 hrs of challenge by Vibrio harveyi. Among the garlic inclusion diets a significantly (p 0.05) different between T2 and T3 after 60 and 72 hrs of Vibrio harveyi challenge. The results indicate that garlic and tamarind powders at 0.5% inclusion can be recommended as supplements to L. vannamei feed to increase growth, survival, immunity, and disease resistance against the pathogen, V. harveyi.EnglishThesis