author(s)
Arun Sharma, Thomgam Ibemcha Chanu and Ashutosh D Deo

abstract
A 42 days experiment was conducted to understand the role of Withania somnifera (ashwagandha) administered through feed in growth, haemato-biochemical response and disease resistance of Labeo rohita (Hamilton, 1822) against Aeromonas hydrophila infection during the period from February to March, 2009 at Department of Aquatic Health and Environment (AHE), College of Fisheries Lembucherra, Tripura, India. W. somnifera fed at 0, 0.1, 0.2 and 0.3 g/100 g of feed for 42 days to L. rohita, led to enhance disease resistance against experimental infection with A. hydrophila. At 0.2 g ashwagandha/100 g of feed, there was an increase in survivability (43.00±0.75%) compared with the control (2.00±0.03%). Moreover, there was a significant increase in growth and feed conversion. There were a significantly higher number of erythrocytes, leucocytes, haemoglobin, haematocrit value, neutrophils, lymphocytes, globulin, A/G ratio and enhanced bactericidal activities compared with the control following feeding with W. somnifera. This suggests that W. somnifera at 0.2 g/100 g of feed can be used as dietary supplement to improve the growth, haemato-biochemical response and disease resistance against A. hydrophila for L. rohita fingerlings.