Sweet orange Citrus sinensis peel is a phutobiotic agricultural waste with bioactive compounds that have potential functional properties as a growth promoter and immune stimulator. This study aims to evaluate the dietary effects of sweet orange peel (SOP) as a feed additive on growth enhancement of juvenile bagrid catfish Mystus nemurus and their disease resistance ability against Aeromonas hydrophila infection Four pxnerimental diets were formulated to contain 0 (SOPO, control), 4 (SOP4), 8 (SOP8) and 12 g/kg (SOPÏ2) ŠOP. After 90 d of the feeding experiment, improvement in weight, gain. specific growth rate, feed conver sion ratio, and protein efficienc y ratio were observed in the fish fed with SOP4. While fish survival was not significantly affected, hepatosomatic and viscerosomatic indices were significantly higher in fish fed with SOP12. Muscle protein was higher in fish fed with SOP’ SOP8, and SOP12 than in control but muscle lipids showed an opposite trend. A 14-d post-challenge test against Å. hydrophila revealed no significant effect on the fish survival. Nevertheless. fish fed SOP4 encountered delaued bacterial infection compared to other treatments and fish fed with SOP0 and SOP4 performed numerically better survival. Infected fish showed skin depigmentation, haemorrhagic sians at the abdomen and anus, internal bleeding, and stomach and intestine enlargement. In conclusion, SOP4 could be recommended as a growth promoter while slightly delaying A. hydrophila infection in M. nemurus.
