Effects of IgY Antibody on Growth, Survival, Immune Responses and Protection against Vibrio parahaemolyticus in Pacific White Shrimp

Abstract

Post larvae 12 (PL 12) of Litopenaeus vannamei (Pacific white shrimp) were subjected to feeding trials to decipher the effectiveness of IgY antibody as a feed supplement. This study aims to comprehend the growth performance, immune responses and survival rate of shrimps following an infection from Vibrio parahaemolyticus. This micro-organism was extracted from shrimps suffering from white feces syndrome (WFS). Post larvae (PL 12) were stocked in twenty 500-L fiberglass tanks at a density of 80 shrimps per tank (four replicate tanks per treatment) and salinity was maintained at 25 ‰. For analyses, shrimps were segregated into five categories based on the dosage of IgY antibody, given along with the standard pelleted shrimp feed (36 % protein) fed four times a day. This additive was fed at a dose escalation of 0, 0.2%, 0.3%, 0.4% and 0.5%. This 30-day trial demonstrated that the shrimps fed 0.5% of IgY additive had the highest average body weight. Besides this, shrimps nourished with 0.5% of IgY additive were found to have increases in growth and development. At the same time, a viable effect of antibody was also seen in the immunity of the shrimps, as evidenced by an escalation in immune responses such as total hemocyte count, phenoloxidase activity, phagocytosis and bactericidal activity of the shrimps. Along with this, a considerable mitigation of the total Vibrio spp. was found in the hepatopancreas of shrimps fed with IgY supplement. The shrimps infected with V. parahaemolyticus and furnished with IgY-feed were discovered to have a notable reduction in mortality rate (25-40 %) in contrast to the control group (60 %). This study demonstrates the positive effects of IgY on growth, immune responses and tolerance to pathogenic V. parahaemolyticus in the Pacific white shrimp.