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¹ Mediterranean Fisheries Research, Production and Training Institute, Kepez Unit, 07192, Döşemealtı, Antalya, Turkey
² Ege University, Faculty of Fisheries, Department of Aquaculture, 35100, Bornova, Izmir, Turkey
³ Mediterranean Fisheries Research Production and Training Institute, Beymelek Unit, Demre, Antalya, Turkey
⁴ Mediterranean Fisheries Research Production and Training Institute, Eğirdir Unit, Isparta, Turkey DOI : 10.4194/1303-2712-v13_3_09 Viewed : 5534 - Downloaded : 4426 This study was conducted to determine the effects of various lengths of starvation periods on following compensatory growth (CG) in rainbow trout under summer conditions (18.1°C and day length of 12.5-14.5 hours). Five treatments with triplicate tanks were as follows: control (C) fed to satiation over 84 days; one (S1), two (S2), three (S3), and four (S4) weeks of starvation; and then refeeding for the remaining eight weeks of the experiment. Starvation periods induced hyperphagia during refeeding but only S1 and S2 were able to catch up with C. Repeated measures of analysis of variance suggested a convergence in body mass but not in body length (structure). Organo-somatic indices of the starvation groups were significantly reduced at the end of starvation periods and restored to levels of the control fish within the first two weeks of the refeeding period. Broadly speaking, starvation longer than one week significantly reduced apparent digestibility of dry matter, lipid, and energy compared with the control group but did not affect protein and ash, and a complete recovery in the digestibility coefficients occurred within two weeks of satiation feeding. There was a linear increase in body moisture and a decrease in lipid and lipid/lean body mass ratio with the severity of starvation periods, but these divergences largely disappeared at the end of refeeding. During the starvation period, the protein synthesis rate (estimated using RNA/DNA ratio in the muscle and liver) reduced but in subsequent refeeding period, it increased in starved fish. The findings of the present experiment suggest that an application of single starvation episodes to elicit CG as a management tool in summer conditions should not be longer than two weeks. Keywords : Rainbow trout, starvation, compensatory growth, body composition, organ indices, nutrient digestibility