that fish fed the VSG3 supplemented diets had significantly higher
respiratory bursts and phagocytic activity than the control group
throughout the trial period. Similar trends in stimulation of
phagocytic activity and RBA after dietary supplementation of
Lactobacillus have been demonstrated in various fish viz.
R. Canadum [10], E. Coioides [13], E. Bruneus [8], O. mykiss [32,33,40],
etc. In contrast, dietary administration of L. delbrüeckii spp. lactis
produced significantly higher PA activity of head kidney leucocytes
after 2 weeks of feeding; but, incrementwas no longer significant at
the end of 3 or 4 weeks [41]. We observed a slight reduction in
respiratory bursts and phagocytic activity at higher probiotic level
(1010 cfu g1) after 60 days of feeding. Previous studies have
demonstrated that feeding of high levels of probiotics for longer
periods affects the phgocytosis and respiratory burst activity in
O. niloticus [14] and R. Canadum [10]. In the lights of our results and
earlier reports, we suggest that long term feeding of proper probiotics
maintain the activation of phagocytic cells throughout the
trial period.