Comparison of meat quality of tench, Tinca tinca, reared in extensive and semi-intensive culture systems

The aim of the study was to examine the production parameters and chemical composition of fillets in tench, Tinca tinca L., farmed in one of two systems: an extensive system based on only natural food (NF) available in the fish ponds; and a semi-intensive system based on natural food plus the addition of formulated feeds supplemented with various oils: fish (FO), rapeseed (RO), soybean (SO), or linseed oil (LO). Proper pond preparation resulted in a favourable amount and structure of natural food in all ponds. The rearing system had a significant influence on the tench yield, muscle lipid contents and fatty acid composition, and the supplemented feed influenced the fatty acid composition. The percentages of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid and total highly unsaturated n-3 fatty acids (n-3 HUFA) were higher in the fish oil and the natural food groups than in the others. The n-3/n-6 ratio in the five dietary treatments was notably variable, and in any case higher in fillets than in the diets. In conclusion, the present study suggests that RO, SO and LO represent effective lipid sources for tench fed formulated diets. On the other hand, tench that fed on naturally available pond foods had a high content of n-3 HUFA in their muscle lipids, but poor growth parameters and low yields

Occurrence and dietary exposure of organochlorine pesticides in common carp obtained from integrated production systems

The aim of this study was to determine the level of the organochlorine pesticides (OCPs) in meat, liver and skin of common carp. Fish were collected in spring and in autumn from fishpond that receives purified water from slaughterhouse. OCPs, including alpha-HCH, beta-HCH, delta-HCH, lindane, heptachlor, aldrin, heptachlor epoxide, trans-chlordane, cis-chlordane, endosulfan I, DDE, dieldrin, endrin, DDD, endosulfan II, dichlorodiphenyltrichloroethane (DDT), endosulfan sulphate, methoxychlor, and endrin ketone, were determined by using a gas chromatography-mass spectrometry method. OCPs were present at low concentrations and only aldrin was detected in all examined tissues. The estimated daily intake for OCPs via common carp from integrated system of production was at the lower level compared with the acceptable daily intake recommended by different organisations, showing no significant risk on consumers