The effects of different cycles of starvation and refeeding on growth of brook trout (Salvelinus fontinalis)

This research was set up to investigate the effects of different fasting cycles of brook trout (Salvelinus fontinalis) on the growth performance. In total, 360 fry with an average initial weight of 5.07±0.15 g were stocked in 4 groups (Control group K, Group A, Group B and Group C) consisting of 30 fish per group in triplicated format. Groups were fed by %5 of their body weight in accordance with the feeding program. The feeding regime was established as every day in the control group while group A 1 day non-feeding 1 day feeding, group B 1 day non-feeding 2 days feeding, group C 1 day non-feeding 3 days feeding and the trial was carried out for 84 days. The average water temperature was detected as 10.99±1.69 °C throughout the experiment period with 15 °C and 6 °C for maximum and minimum temperatures, respectively. The highest Final Weight (WF) and the Thermal Growth Coefficient (TGC) was measured as 40.53±1.36 (P<0.05) and 1.27±0.04 (P>0.05) in group C and the lowest as 33.31±1.19 and 1.02±0.04 in group A, respectively at the end of the trial. There were no statistical differences among groups K, A and B (P>0.05) in terms of Specific Growth Rate, while the lowest value was in group A as 2.22±0.05. The best Feed Conversion Rate (FCR) was measured in group A as 1.12. The Hepatosomatic Index was found to be 2.10±0.34, as highest value in group C (P>0.05). Visceral Somatic index was measured at the highest level in group A with 13.46±1.48 (p<0.05). Body protein composition was detected as 21.19±0.40 and 21.74±0.55 in groups K and B, respectively, higher values observed compared to groups A and C. According to the results of present study, one-day non-feeding followed by 3 days feeding regime is suggested for brook trout in lower temperatures which will be more beneficial thus economical taking into account the growth parameters, feeding parameters and nutritional contents.