The Effects of two different lipid sources (fish oil and soybean oil) on growth performance and body fatty acid composition of sea bass (Dicentrarchus labrax L. )

ABSTRACT PhD THESIS THE EFFECTS OF TWO DIFFERENT LIPID SOURCES (FISH OIL AND SOYBEAN OIL) ON THE GROWTH PERFORMANCE AND BODY FATTY ACID COMPOSİTİON OF SEA BASS (Dicentrarchus labrax L.) ARZU ÖZLÜER HUNT DEPARTMENT OF FISHERIES INSTITUTE OF NATURAL AND APPLIED SCIENCES UNIVERSITY OF ÇUKUROVA Supervisor: Asst. Prof. Dr. Nazmi TEKELÎO?LU Year: 2003, Page 97 Jury : Asst. Prof. Dr. Nazmi TEKELİO?LU Prof. Dr. Gürkan EKİNGEN Prof. Dr. Abdurrahman POLAT Prof. Dr. Ercan SARJHAN Asst. Prof. Dr. M. Ayçe GENÇ In this study, the effect of two different lipid sources (fish oil and soybean oil) on growth performance and body fatty acid composition of sea bass {Dicentrarchus labrax L.) juveniles were investigated. Sea bass juveniles (4.80± 0.2 g) were used as fish material. Feeding study was conducted over a 15 weeks time frame. Firstly, diets containing 12% lipid were prepared in 5 different groups with soybean oil and fish oil. Other dietary contents such as protein, vitamin and minerals were maintained the same levels in all groups. The only changed was the lipid content in diets. In the second part of the study, dietary components and fatty acid composition of whole body and filets were investigated after the feeding trial. The first diet group containing 12% fish oil had the highest growth performance at the end of the experiment. Following this the second highest growth performance was obtained from the fifth group containing 12% soybean oil. Weight gain and spesific growth rate between first group and the others were significant (PO.05). Lipid content of whole body and filet on the first group were less than those of other groups. The lipid content of whole body and filet obtained from the first group was significant from the other groups (P<0.05). In this study, saturated, monounsaturated and polyunsaturated fatty acids were investigated. The observed amount of ra-3 fatty acid decreased but co-6 fatty acid increased with the supplementation of soybean oil. Saturated, monounsaturated and polyunsaturated fatty acid changes in all groups were significant (P<0.05) Keywords: Seabass, fish oil, soybean oil, growth, essential fatty acids. II