Influence of enviroment culture and feeds on content of fat and fatty acids spectrum in filets of European catfish (Silurus glanis L.)

The object of this work was to verify influence of feed and surroundings on lipids content and fatty acids spectrum in musculature of European catfish (Silurus glanis) cultivated in intensive conditions. Within years 2000–2002 feeding tests with European catfish of initial weight from 60 to 500 grams were executed. For rearing of fish recirculation system at Department of Fisheries and Hydrobiology of Mendel University of Agriculture and Forestry in Brno and facility of farm in Tisová (Czech Fisheries Company, s.r.o. of Marianské Lázně) using flow through system warmed by water from the Tisová thermal power plant were used.Feeds for salmonid fish with differential protein (35–48,5 %) and lipid (13–26%) content were tested. The temperature of water in all fluctuated was from 17–26 °C. Frequency of feeding was three times a day. Quantity of feeding dose varied depending on weight of fish from 1 to 2 % of weight of stocking rate.Spectrum of fatty acids in used feeds corresponds to composition of fatty acids in musculature of European catfish (Silurus glanis). This spectrum is influenced by quality of used components during feed production; breeding surroundings did not show any influence on spectrum of fatty acids in musculature of fish. SFA content was in range 27–32,60 %. Rate n–3/n–6 PUFA was highest in trial TISOVÁ 2001 (3,78). When compared Aqualife 17 feed, the narrowest rate n–3/n–6 PUFA (1,19) was found out in recirculation system in during the year 2000.Dry matter in musculature of European catfish (Silurus glanis) fluctuated in range 16,03–26,34 %. Fat content varied from 0,83–6,68 % depending on used feeding diet. Ammount of fat in musculature of European catfish is comparable or lower than data quoted in literature.Comparing influence of breeding surroundings on fat content in musculature of European catfish, we found out, that European catfish bred in recirculation system reached in average higher percentage content of fat in musculature than fish bred in flow through system.