EFFECT OF DIETARY LIPID SOURCE ON DIGESTIBILITY AND HEALTH PARAMETERS IN CICHLIDS

Guillaume P. Salze*, Shimaa M. Salem, D. Allen Davis, Donna Snellgrove
School of Fisheries, Aquaculture and Aquatic Sciences, AL, USA 36849-5419
gsalze@ auburn.edu
 

Cichlids constitute a family of teleost of primary economic importance: hundreds of species are popular ornamental species while tilapia species provide food and/or revenue to people in numerous countries worldwide. Dietary lipids are important nutrients, as a source of dietary energy as well as of precursors of physiologically active molecules (e.g., hormones, eicosanoids). Consequently, the dietary lipid profile influences growth, health, and metabolism of the individuals. However, the demand for fish oil, which has been the traditional source of essential fatty acids, has increased while global production has remained stagnant. Consequently, the search for alternative lipid sources that would support the energy and health needs of fishes has been a major focus in fish nutrition.

In this study, 7.8g Nile tilapia juveniles were fed one of eight diets formulated with fish, squid, algae, fungal, flax, camelina, canola, or soy oils and grown for 10 weeks. Blood samples were collected and analyzed for hematocrit and serum alkaline phosphatase (SAP), alanine transaminase (ALT) and aspartate transaminase (AST) activities as well as bilirubin, cholesterol, triglycerides and bile acids. In addition, digestibility coefficients of the various lipid sources were determined.

There were no significant differences among diets in growth rates (Fig. 1, overall average final body weight 80.6 ± 5.5g; mean ± standard deviation), feed efficiencies or feed intake. Blood chemistry also revealed that none of the measured parameters were significantly impacted by dietary lipid source (Fig.2). The results will be further interpreted considering the digestibility data