The present experiment was carried out to study the effect of different dosages of b-glucan suspension
derived from barley on the innate immune response and disease resistance of Anabas testudineus spawns
against infection caused by Aeromonas hydrophila. Four different dosages of b-glucan suspension in
phosphate buffered saline at the rate of 0, 5, 10, 15 mg l1 were taken and 8 days old spawn were exposed
for 2 h and 3 h. The cell suspension of spawn was assayed for total protein, acid phosphatase activity,
lysozyme activity, bactericidal and NBT. Further, the spawns were challenged with 3 105 cells ml1 of
A. hydrophila and survivability percentage and immunological parameters were assayed upto day 7. On
day 7, most of the immunological parameters such as lysozyme activity, bactericidal activity and NBT
activity were significantly enhanced after exposing the fish to all the concentrations of b-glucan. Challenge
study indicated least mortality in the group of spawns immersed in 15 mg l1 b-glucan suspension
for 3 h. Thus, 3 h exposure to b-glucan suspension could reduce the mortality and increase the immunity
of A. testudineus spawns.
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