Department of Biology and Aquaculture, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
CHERPOKOV, Y., 2018. The influence of Salvia hispanica as a substitution of fish meal on the growth performance and economic parameters of common carp (Cyprinus carpio L.), raised in net cages. Bulg. J. Agric. Sci., 24 (Suppl. 1): 125–131
The purpose of the study was to determine the effect of the addition of chia as a substitution of fish meal in extruded feed on the growth intensity and economic efficiency of common carp, grown in net cages. The fish were kept in net cages, each of them with an effective water volume of 1 m3, which are part of a fish farm “Dani”, situated in the Studen Kladenets dam. Five hundred and forty common carps, were divided into three groups – control (A), experimental B and C, each of them with three replicates, with a mean initial live weight, respectively 53.5±1.31 g, 53.4±1.33 g and 53.4±1.24 g (p>0.05). The feed was extruded pellets with a size 3.5 mm. The feed content for fish from experimental groups was as follows: for the control group (A) - 12% fish meal, for the group B - 6% fish meal and 12% chia, and that for the group C without fish meal, with a content of 25% chia. The duration of the trial period was 60 days. To monitor the impact of the addition of chia as a substitution of fish meal to extruded pellets on the growth intensity of common carp (Cyprinus carpio L.), control catches were performed at a 20-day interval. The live body weight (BW, g) in the control catches was established, with the carps of each group being weighed together and so the average weight of one fish calculated. At the end of the experiment, fish growth (g), their survival rate (%) and feed conversion ratio (K) were calculated. In the middle of the experimental period, there is a tendency for a higher live body weight in the fish of control group A, where extruded pellets contained 12% fish meal, compared to the values of this indicator of individuals in the groups B and C, fed with granules with content of 12% and 25% chia. The same trend remained at the end of the experiment, with the live weight, being highest in the common carp from the control group (A) - 152.89 ± 18.57 g, followed by that of fish from the experimental group B - 144.25 ± 14.77 g and the one of individuals from C group - 138.66 ± 14.59 g and the differences are statistically proven (p<0.03, p<0.001). Calculated economic conversion ratio (ECR) was 2.10 for the fish from the control variant A and it was accordingly with 59% and 229% lower, compared with the value of the same parameter, calculated for the individuals from experimental group B and C.