|Rawles, Steven - Steve|
Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: 2/21/2013
Publication Date: 2/21/2013
Citation: Bowzer, J., Trushenski, J., Rawles, S.D., Barrows, F., Gaylord, T.G. 2013. Carp-based aquafeeds and market-driven approaches to controlling invasive Asian carp in the Illinois RiveR[abstract]. Book of Abstracts Aquaculture America 2013: Strike a Chord for Sustainable Aquaculture, February 21-25, 2013, Nashville, Tennessee. P. 119. Interpretive Summary:
Technical Abstract: Incentivizing ‘overfishing’ through the creation of high value markets for rendered carp products such as fish meal (FM) is a promising strategy to reduce the density of silver carp and bighead carp (collectively referred to as Asian carp) in the Illinois River. However, the nutrient content and digestibility of Asian carp and rendered carp FM must be determined to assess the suitability of this resource for use as an alternative to marine-origin FM in aquafeeds. To determine seasonal and geographical variation in body composition, Asian carp were collected from six reaches of the Illinois River during the fall, spring, and summer (12 silver and 12 bighead carp targeted for each reach and season). Standard digestibility studies with sunshine bass and rainbow trout were used to determine the quality of commercially rendered carp FM as a potential feedstuff. Results indicate slight geographical and seasonal variation exists in body composition, though both species represent protein-dense raw materials (Figure 1). There is an apparent trend of increasing lipid content from lower to upper reaches, suggesting resource limitation is affecting body composition in some areas. Although Asian carp generally appear to be a good source of long-chain polyunsaturated fatty acids (LC-PUFA), the concentration of LC-PUFA is higher in carcasses collected in Fall (24.7% of FAME) than Summer (13.3% of FAME). Preliminary digestibility data suggests that protein in carp FM is less digestible than menhaden FM, but lipid digestibility is comparable between these feedstuffs (Table 1). Overall, Asian carp FM appears to be a highly-digestible, nutrient-dense feedstuff that is suitable for high-value markets such as aquafeed production. These markets may be developed to support the aquaculture industry, and efforts to control invasive Asian carp.