The Effect of Peptidoglycan on Immune Response in Black Tiger Shrimp (Penaeus monodon Fabricius)

Abstract

The effect of peptidoglycan on immune response in Black Tiger Shrimp (Penaeus monodon Fabricius) was conducted under laboratory conditions. P. monodon (13±2 g) were fed for 7 days with diets containing graded levels of PG (0, 0.06, 0.12 and 0.18 g/kg feed). The immune responses were
measured by phenoloxidase, superoxide anion, bactericidal activity, clearance ability and resistance against Vibrio harveyi. The results showed that shrimp which fed on diets containing PG 0.18 g/kg had these immune parameters at significantly higher (P<0.05) than PG 0.06, 0.12 g/kg and control. The study for optimum time of using PG 0.18 g/kg was determined with P. monodon (13±2 g) for 10 weeks. In weeks 1-4, shrimps were fed with the diet containing PG at 0.18 g/kg at 0, 3, 5 and 7 days/week. In weeks 5-8, shrimps were fed with normal feed and in weeks 9-10, shrimps were fed with same concentration and frequency as weeks 1-4. The results showed that optimum time for use of PG 0.18 g/kg was 5 days/week. This application could increase total hemocytes, phenoloxidase, superoxide anion and bactericidal activity which were significantly different (P<0.05) from 3 days/week and control but not significantly different (P>0.05) from 7 days/week. In conclusion, oral administration of PG at 0.18 g/kg diet for 1 month (5 days/week), normal feed for 1 month and PG 0.18 g/kg diet for another month (5 days/week) could effectively enhance the immune system of P. monodon.