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

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A REVIEW OF LIPID NUTRITION RESEARCH FOR THE LARGEMOUTH BASS
(Micropterus salmoides)
James H. Tidwell*, Shawn D. Coyle and Leigh Anne Bright
Aquaculture Research Center
Kentucky State University
103 Athletic Road
Frankfort, KY 40601 USA
james.tidwell@kysu.edu
The largemouth bass (Micropterus salmoides) is the largest member of the North American family of Centrarchidae. Research
on this species has primarily focused on hatchery production to sizes of ≤ 5 cm. In recent years interest has increased in the
development of methods for growing largemouth bass to larger sizes, especially for live sales into ethnic Asian Markets. However,
when compared to its economic importance, and high percentage of production cost accounted for by feed costs, relatively
few studies have addressed largemouth bass nutrition with even fewer being devoted to lipid nutrition.
An early study by Tidwell et al. (1996) suggested that for a warmwater, freshwater species, largemouth bass might require
relatively high levels of polyunsaturated fatty acids (PUFA). Levels of DHA (22:6n-3) in the lipids of the bass egg and muscle
tissues were >290% higher than levels measured in the diets, possibly indicating relative importance. In a subsequent study,
Coyle et al. 2000 replaced menhaden fish oil in the diets with squid oil to increase concentrations of PUFA and HUFA, and
especially DHA (22:6n-3). Although there was no increase in growth or feed conversion efficiency, fish fed the diet high in
DHA had significantly lower (P ≤ 0.05) whole body lipid levels and significantly higher (P ≤ 0.05) protein levels than fish fed
the other three diets.
Two more recent studies evaluated the use of lipids from different sources to replace fish oil in largemouth bass diets. Subhadra
et. al. (2006) evaluated replacement of menhaden oil with either canola oil, chicken oil, or a menhaden + chicken blend. In fish
fed canola or chicken oils body HUFA concentrations were reduced but performance was not different from fish fed the fish
oil diets. However, growth was low relative to fish fed commercial diets. Another study (Tidwell et al. 2007) also compared
alternative lipid sources including corn oil, sunflower oil (higher oleic), linseed oil and specialty oils including algal oil (high
22:6n-3) and fungal oil (high 20:4n-6). At the end of the study period, there were no significant differences (P > 0.05) between
treatment groups in terms of survival (98%), weight gain (595%), specific growth rate (2.2% per day), feed conversion ratio
(1.5), percent protein deposited (28%), or hepatosomatic index (2.3). Whole-body proximate composition was not significantly
affected (P > 0.05) by sources of added lipid, but whole- fatty acid composition showed large differences and primarily
reflected the fatty acid compositions of added oils. Largemouth bass may be able to use diets containing vegetable- and animalsource
lipids, which are less expensive than the previously recommended fish oil.