February 15-18, 2009 Washington State Convention Center Seattle ...

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EVALUATION OF GROWTH PERFORMANCE ON POND-RAISED SUNSHINE BASS
WHEN FED PRACTICAL DIETS WITH REDUCED PROTEIN LEVELS AND CONTAINING
A COMBINATION OF POULTRY-BY-PRODUCT MEAL AND SOYBEAN MEAL AS TOTAL
REPLACEMENT OF MENHADEN FISH MEAL
Kenneth R. Thompson*, Linda S. Metts and Carl D. Webster
Aquaculture Research Center
Kentucky State University
Frankfort, KY 40601 USA
ken.thompson@kysu.edu
Since protein is generally the most expensive component in aquaculture diets, and fish meal (FM) is one of the most expensive
macro-ingredients (used in high percentages), a 459-day feeding trial was conducted with juvenile (mean individual weight
35 g) sunshine bass (Morone chrysops X M. saxatilis), to be grown to market-size phase-III fish, to evaluate growth, survival,
and feed efficiency when fed practical diets containing soybean meal (SBM) and poultry by-product meal (PBM) as complete
replacements for menhaden FM and simultaneously reducing dietary protein (32%, 36%, and 40%) compared with fish fed a
commercial high-quality finfish diet containing 30% FM, 40% SBM, and 40% crude protein (CP). The feeding trial was conducted
in 12, 0.04-ha earthen ponds and fish were stocked at a rate of 300 per pond.
When analyzed from the beginning of the study until harvest, there were no significant (P > 0.05) differences in mean final
weight, percentage weight gain, specific growth rate (SGR), percent survival, diet fed, and feed conversion ratio (FCR) among
treatments, and averaged 771 g, 2103%, 0.68%/day, 94.3%, 1589.5 g/fish, and 2.16, respectively (Table 1).
Results from the present study indicate that pond-grown sunshine bass can be fed a diet with 32% CP and formulated without
menhaden fish meal (FM) and no adverse effects on growth, survival percentage, and feed conversion ratio. This is the first
study to report that complete substitution of menhaden FM is possible when sunshine bass are grown in ponds to market-size
for a period 459 days when alternative protein sources, i.e., SBM and PBM are provided in the diet, and simultaneously reduce
dietary crude protein levels. Results from this study may help reduce diet costs for sunshine bass producers and feed mills,
thereby increasing profitability.