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Artificial feed including low cost, alternative, and nonconventional animal protein in replacement to
costly shrimp meal were formulated and their impact on survival and growth of rainbow trout,
Oncorhynchus mykiss (Walbaum), during exogenous feeding in raceways were compared. Three
feed formulations of silkworm pupae (SWP), silkworm moth (SWM), and synthetic amino acids
(SAA) were evaluated against shrimp meal (SML) acting as control through feed efficiency
indicators. Four diets (three formulated and one control) were fed to the free swimming fries, fries,
and fingerlings for 150 days (5 months). There was significant difference in survival (P<0.01) and
growth (P<0.05) of above mentioned stages. Survivability with SML diet fed stages showed
superiority (P<0.01) among other feed formulations, SWP came next, SWM less, and SAA least.
Growth with SWP diet fed stages exhibited superiority (P<0.05) amongst all the diets and SAA
lowest whereas SML and SWM lied in between. Therefore, absolute growth rate, specific growth
rate, relative growth rate, and feed efficiency were highest due to SWP, higher due to SML, low due
to SWM, and lowest due to SAA. However, condition factor was highest due to SWP, higher due to
both SAA and SML, and lowest due to SWM. Unlike other feed indicators, feed conversion ratio
exhibited highest due to SAA, higher due to SWM, low due to SML, and lowest due to SWP. The
highest growth period was observed during April to May and lowest during December to January in
all the diets. Cost analyses revealed SWM containing diet cheapest with low production cost, SWP
cheaper with lowest, SAA cheap with highest, and SML costly with high production cost. The study
confirmed natural protein SWP, SML, and SWM were superior to SAA. Results indicated cost
effective SWP containing diet could be used as better alternative to completely replaced SML
without compromising survival and growth.
Keywords: Formulated artificial feed, survival and growth, rainbow trout, exogenous feeding, raceways