THE INFLUENCE OF FEEDING INTENSITY ON GROWTH PERFORMANCE OF RAINBOW TROUT JUVENILS

Mirela Creţu, V. Cristea, Lorena Dediu, Raluca Cristina Andrei (Guriencu)

Abstract
   The purpose of this experiment was to evaluate how feeding intensity influence the growth performance of juvenile rainbow trout (Oncorhynchus mykiss) reared in a recirculating system. A number of 152 rainbow trout with an average weight of 174.41±0.73 g were divided into four rearing units in order to create the same stocking density (20 kg/m3). The fish were fed a 41% protein feed. Two variants were compared V1 (B1, B2) and V2 (B3, B4), with repetition. In V1- 1.0% feed from total biomass and a double amount of feed in V2-2.0% from total biomass. At the end of the experiment were obtained average body mass of 224.09±0.20 g in variant V1 and 245.59±0.73 g in variant V2. Specific growth rate (SGR) varied as follows: V1-0.95 g% / day, V2-1.33 g% / day. Regarding the feed conversion factor (FCR), the better values were obtained in V1 variant -0,93 g feed/g gain biomass, while in V2 we obtain a value of FCR-1.22g feed/g gain biomass. The parameters of fish growing showed that changing the quantity of fodder, the fish growing was positively influenced.

Key words: rainbow trout, feeding intensity, recirculating system