Investigation of the effect of nutritional supplement use on growth performance and survival rate of rainbow trout (Oncorhynchus mykiss)

This study was carried out for 60 days to examine the effects of a commercial product (Viusid Aqua) added to fish feeds as a nutritional supplement on the growth performance and survival rate of rainbow trout (Oncorhynchus mykiss) fry. At the beginning of the study, trout fries with the mean of 2.80±0.01 g were used. The nutritional supplement ratio in the feeds used in the experimental groups was formed as 0% (Control), 4% (VA1), 8% (VA2) and 12% (VA3). Nutritional supplementation was made by adding commercial trout feed in the first 20-day period. The mean water temperature, dissolved oxygen and pH values in the water used in the study were 13.72±0.04 ℃, 8.35±0.12 mg/L and pH 7.29±0.04, respectively. At the end of the experiment, the mean live weight gain of the fish belonging to their groups was found to be the best in the VA1 group with 16.82±0.15 g (p<0.05). The mean feed conversion ratio was 0.88±0.18, the specific growth rate was 3.47±0.24 g/day, and the condition factor was 1.28±0.05 in the VA1 group fed with 4% additive feed. It was determined that the VA1 group was better in terms of other growth performances (feed conversion ratio, specific growth rate and condition factor), but there was no statistical difference between the groups (p>0.05). At the same time, there was no statistical difference between the groups in terms of survival rate (p>0.05). However, the best survival rate (99.67±0.58%) observed in the groups was found in the VA1 group.