Growth performances and hematological characterisation of rainbow trout (Oncorhynchus mykiss Walbaum, 1792)

In present study correlations between hematologic characteristics and growth performances of rainbow trout were investigated. Fish were provided from a raceway trout farm located in the valley of the river Jerka near the city of Novi Pazar (N:43°13’67’’; E:20°43’96’’). The farm consists of 8 concrete lined production ponds (22 x 3 m x 1,2 m each) in which water is exchanged 75 times per day. After stocking fish from production ponds are being monthly classified into two groups depending on their body mass and body length and larger fish are transferred in separate ponds. For this study one year old fish were sampled. 25 from slower and 25 from faster growing group. Analyses were performed in 4 consecutive days in accordance with animal welfare regulations (Official Gazette of the Republic of Serbia 41/2009). Fish growth performances were estimated from body mass, total and standard body length and Fulton condition factor. Hematological characterization of rainbow was established on the basis of Red Blood Cell (RBC) and White Blood Cell (WBC) count, hemoglobin concentration, Packed Cell Volume (PCV), Mean Corpuscular Volume of erythrocytes (MCV), Mean Corpuscular Hemoglobin in individual erythrocyte (MCH) and Mean Corpuscular Hemoglobin Concentration (MCHC) in a liter of erythrocytes. The results obtained were statistically analyzed by SPSS. It was found out that there exist significant correlation between hematological and growth characteristics. High linear regression coefficients can explain mass and length gain by hematological parameters