Slaughter yield, proximate composition, and flesh colour of cultivated and wild perch (Perca fluviatilis L.)

The aim of this research was to determine the slaughter yield, proximate composition, and flesh colour of cultivated (CP) and wild perch (WP). The study material was composed of fish obtained from intense fattening on formulated feed (age 1+, mean body weight, BW 116 g) and wild specimens caught in a lake (age 3+, BW 119 g). The biometric traits of the two groups of fish did not differ with regard to body weight, total length, body length, or condition coefficient. CP had significantly higher both maximum body height and relative body profile. Its slaughter yield was significantly lower than that of WP. This fact was due to heavier viscera, which included more perivisceral fat and larger liver. CP had significantly higher values of the viscerosomatic (12.0 vs. 6.4) and hepatosomatic (1.9 vs. 1.7) indices as well as perivisceral fat (7.0 vs. 1.2) than WP. Chemical analysis of fish fillets indicated that protein, fat and water concentrations differed significantly between the two types of fish. The higher content of dry matter in CP was a result of higher fat and protein contents. The fillets of the two groups of perch differed with regard to the saturation of green and yellow pigments; CP exhibited lower values of the parameter a* and higher values of the parameter b* (P less than 0.01).