Effects of Ethanol Tumeric (Curcuma longa Linn.) Extract Against Shrimp Pathogenic Vibrio spp. and on Growth Performance and Immune Status of White Shrimp (Litopenaeus vannamei)

Abstract

The effects of ethanol turmeric extract against shrimp pathogenic Vibrio spp. were investigated. It was found that ethanol turmeric extract inhibited the tested Vibrio spp. and the minimum inhibitory concentrations of ethanol turmeric extract on Vibrio harveyi, V. cholera, V. parahaemolyticus, V. alginolyticus, V. vulnificus and V. fluvialis were 0.47, 0.47, 0.94, 0.47, 3.75 and 0.47 mg/disc, respectively. The effects of ethanol turmeric extract on survival rate, feed conversion ratio and growth rate of white shrimp were examined using different levels of ethanol turmeric extract in feed. The results showed that there were no significant (P > 0.05) differences in survival rate and water quality. However, the percentage of average day growth and weight gained were significantly (P < 0.05) higher with feed that contained ethanol turmeric extract at 7.5 and 15 g/kg of feed when compared with the control. The efficacy of ethanol turmeric extract as an immunostimulant for white shrimp showed that the total hemocyte count, phenoloxidase activity and bactericidal activity increased as the levels of ethanol turmeric extract in feed increased. The ratio of ethanol turmeric extract that gave the best immunostimulatory effect was 15 g/kg of feed. It was found that the effect of ethanol turmeric extract at a ratio 15 g/kg of feed on the survival rate of white shrimp immerged with Vibrio harveyii was significantly (P < 0.05) higher than the control group.