Effect of winter feeding frequency on caged juvenile rainbow trout growth

New research results of the morphological study on Ladoga Lake juvenile rainbow trout grown in cages under different winter feeding regimes are presented in the article. No differences in the mass and body size of the juveniles grown under different feeding schedules (1 time in 7 days and 1 time in 3 days) were revealed. The state and index of the rainbow trout internal organs (heart, spleen, gills, liver, stomach and intestines) speak of the fish normal development during winter season in conditions of different feeding schedules. It was concluded that the effective growth of the caged rainbow trout is possible at the water temperature less than 2 °С during winter season with once-a-week feeding schedule. Such feeding regime is facilitative in the increase of the cage farm profitability.