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 and wild perch (Perca fluviatilis). 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 (U), body length (Lc), or condition coefficient (P > 0.01). The cultivated perch had both higher maximum body height (H) and relative body profile (Rp) (P <= 0.01). The cultivated perch has a significantly lower slaughter yield (P! 0.01). This dependence stems from the heavier viscera, which included more perivisceral fat and larger liver. Cultivated perch had significantly higher values of the viscerosomatic (VSI; 12.0 vs. 6.4), hepatosomatic (HSI; 1.9 vs. 1.7), and perivisceral fat (IPF; 7.0 vs. 1.2) indices. The analysis of the proximate composition of fillets from wild and cultivated perch indicated that the ratios of protein, fat, water were significantly different (P! 0.01). The higher content of dry matter in the cultivated perch 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 pigment; the cultivated perch exhibited lower values of parameter a* and higher values of parameter b* (P <= 0.01).