The Effect of Different Feeding Protocols on Compensatory Growth of Black Sea Trout Salmo trutta labrax

The objective of this study was to determine the effects of different feeding protocols on compensatory growth, feeding rate, and feed conversion efficiency of Black Sea Trout Salmo trutta labrax. To our knowledge, no previous feeding experiments with Black Sea Trout have incorporated a fasting period to simulate the handling and acclimation conditions experienced by farmed fish. Fifteen fish per tank (10.69 +/- 0.06cm and 13.22 +/- 0.14g, mean +/- SE) were stocked into 40-L fiberglass tanks. Fish were fed with different fasting-feeding regimes for 95 d and were equally allotted to four treatments (T-cont: control; T5-10: 5 d fasting, 10days feeding; T10-10: 10 d fasting, 10 d feeding; and T15-10: 15 d fasting, 10 d feeding) with three replicates per treatment. The results indicated that length (P = 0.0005), weight (P = 0.000), condition factor (P = 0.013), and specific growth rate (P = 0.014) were significantly affected by the interaction between feeding and time. All fasting treatments showed partial compensation during refeeding. There was an increase in daily feeding rate and feed conversion efficiency in fasting treatments compared with the control treatment. In contrast, at the end of the experiment specific growth rate, condition factor, and body weight in fasting treatments were significantly lower compared with the control treatment. We concluded that there was partial compensation of growth with regular refeeding after periods of feed deprivation (e.g., 5, 10, or 15 d) over a long term and a shorter fasting period may be preferred in order to achieve compensatory growth. Received November 9, 2012; accepted April 9, 2013