The experiment involved 275 (±20.0) g mean individual weight young carp, stocked in 2 m³ cages at a density of 6 individuals per cage. Over the 58 days of the experiment, the fish were fed an extruded feed of 45.5% crude protein, 24.2% total lipids, and 23.1 MJ·kg^-1 gross energy contents. The experimental treatments differed in the magnitude of daily feed ration, calculated relative to the fish metabolic weight (W^0.8). The carp receiving feed rations of 0.8, 1.8, 2.6, 3.2, and 3.6%W^0.8 showed specific growth rates (SGR) of 0.98, 1.91, 2.41, 2.49, and 2.51%·d^-1, respectively, the respective food conversion ratio (FCR) values being 0.97, 1.04, 1.14, 1.37, and 1.52. The highest apparent lipid retention (aLR= 76.27 %) and the highest amount of energy retained (ER= 46.96%) were recorded in the carp fed the 2.6W0.8 feed ration, the highest apparent net protein utilisation (aNPU= 40.14%) being observed in the fish fed the lowest feed ration. The results demonstrate energy-rich feeds to have a potential for successful application in intensive culture of the C_2-3 carp kept in cooling water.

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