Role of dietary probiotic Ecotec in growth enhancement, thyroid tuning, hematomorphology and resistance to pathogenic challenge in Labeo rohita juveniles

Abstract

In the present study effects of a commercial probiotic, Ecotec on growth, thyroid hormone profile, hematology, immuno-biochemical responses, monocyte morphology and survival against pathogenic challenge in Labeo rohita juveniles have been investigated. Two different concentrations of the probiotic (t1: 8 × 107 CFU/g feed and t2: 16 × 107 CFU/g feed) were administered to the fish. Probiotic treated fish showed a high growth increment as compared to the control. Level of thyroid hormones T3 and T4 was found to be lowered while TSH level was high in probiotic treated groups. Total Leukocyte Count was significantly low in the probiotic supplemented groups. The Differential Leukocyte Count showed abundance of lymphocytes and monocytes in the control group while neutrophils and basophils were abundant in the probiotic treated groups. Biochemical parameters (Albumin and Globulin) were high in probiotic fed groups. Immunological paraameters (Super oxide dismutase, Catalase, Myeloperoxidase and Lysozyme) were significantly high in probiotic fed fish. Monocyte morphology in control group showed a pronounced phagocytic activity in comparison to probiotic treated groups. Infection with Aeromonas hydrophila showed that probiotic treated fish had a better survival rate. In conclusion Ecotec supplementation enhanced growth and improved immunity in Labeo rohita juveniles.

Keywords

• probiotic
• labeo rohita
• growth
• thyroid hormone
• immunity
• survival