Growth performance and haematological and immunological indices of rainbow trout (Oncorhynchus mykiss) fingerlings supplemented with dietary Ferulago angulata (Schlecht) Boiss

Abstract

In this study, the effects of Ferulago angulata extract on the growth, haematological, and immunological indices of rainbow trout (Oncorhynchus mykiss) fingerlings were evaluated. Basal diet was supplemented with 0 (control), 0.5, 1, and 2 g·kg-1 F. angulata and was randomly allocated to experimental fish of an initial average weight of 7.45 ± 0.02 g. After 8 weeks of experiment, the fish supplemented with F. angulata extract showed increased but non-significant (P > 0.05) growth performance. No significant differences were found between trial control groups in haematological indices such as red blood cell count, haematocrit, and haemoglobin, but there was a significant increase in white blood cells, lymphocytes, neutrophils and monocytes in the F. angulata extract groups (P < 0.05). Also, there were significant differences between the fish supplemented with dietary F. angulata extract and the control group regarding immunological indices, including immunoglobulin M, lysozyme, and classical and alternative complement pathway (P < 0.05). These findings suggest that the administration of F. angulata extract has a positive effect on the immunological indices and the immune system activity in rainbow trout fingerling.