Condition factor and identification of amino acid composition of three trout species in the western region of Ukraine

Indicators of the condition factor, growth rate, and quality of the final products of cultivated objects are important parameters for the effective management of cold-water fish farming. These indicators are also used as a way to control the impact of environmental factors on fish, which requires constant research in the context of intensification of the aquaculture sector. The research is aimed at determining the condition factor and the amino acid composition of muscle tissues of  Salmo trutta fario (Linnaeus, 1758),  Oncorhynchus mykiss (Walbaum, 1792), and  Salvelinus fontinalis (Mitchill, 1814) under the conditions of the western region of Ukraine. The results of the condition factor showed that S. fontinalis had the highest value with 1.52±0.0340, and O. mykiss and S. trutta showed the lowest value with 1.33±0.0361 and 1.26±0.0181, respectively. Food conversion ratios were similar for S. fontinalis and O. mykiss (1.0), whereas S. trutta showed higher values (1.4). The specific growth rate was highest in rainbow trout. The specific growth rate was higher for rainbow trout (1.4) compared to the brook trout (1.32) and brown trout (1.28). The maximum content of protein, total amino acids (TAA), total essential amino acids (TEAA) and nonessential amino acids (TNEAA) we registered in brook trout. The muscle tissue of the investigated fish species is a well-balanced source of the nutrition energy in terms of the ratio of total essential to total nonessential amino acids (TEAA:TNEAA ratio).