Different manufacturers fish feed aplication in growing rainbow trout in the industrial aquaculture conditions

This paper presents the results of investigation of feeding rainbow trout Oncorhynchus mykiss (Walbaum, 1792) young-of-the-year (YOY) with granular feeds Aller Silver (Aller Aqua) and Efico Alpha 717 (BioMar). It is shown that both studied feeds provide a similar mass accumulation dynamics of rainbow trout YOY and similar feed conversion ratio. Plant proteins present in both studied feed. The intestinal mucosa total proteolytic activity of rainbow trout in both experimental groups did not differ significantly. In muscles of rainbow trout that were fed with feed Alier Aqua, protein content is 14% higher than in the muscles of fish fed with feed BioMar. In the liver, such differences were not noted. Both feeds are characterized by a predominance of glutamine and glutamic acid in total amino acids content. The contents of lysine, leucine, asparagine and aspartic acid are enough high at both feeds. However the share of sulfur-containing amino acids (methionine and cysteine) are the smallest. Ratio of amino acids in both investigated feed in the overall corresponds to the amino acids ratio in muscle tissue and liver of rainbow trout YOY. Significant predominance of glutamine and glutamic acid observed in the liver and in the muscles of fish both experimental groups. Among the essential amino acids the largest proportion accounted for leucine, arginine and lysine in muscle and liver of the studied fish.