Fermented medicinal herbs improve hematological and physiological profile of Striped catfish (Pangasianodon hypophthalmus) [version 3; peer review: 1 approved, 2 approved with reservations]

This study sought to determine the effect of fermented medicinal herbs (FMH), i.e. cutchery (Kaempferia galanga), turmeric (Curcuma longa) and curcuma (Curcuma xanthorrhiza) in combination with molasses and probiotic drink (Yakult), administered orally on the hematological and physiological profile of striped catfish (Pangasianodon hypophthalmus). A complete randomized design (CRD) experiment was used with four levels of treatments, namely P0 (control), P1 (FMH 100 mL/kg), P2 (FMH 200 mL/kg) and P3 (FMH 300 mL/kg) of feed. The fish were kept in a farm in cages at 75 fish/m3 and fed with the experimental diets for 60 days. The results revealed that FMH (P2) dietary administration improved hematological and physiological profile of catfish, i.e total erythrocytes of 2.81 x 106 cells/mm3, hematocrit values of 39.00%, hemoglobin levels of 10.73 g/dL, total leukocytes of 11.41 x 104 cells/mm3, blood glucose 97.33 mg/dL, and total serum protein 4.10 mg/dL compared to controls with 1.89 x 106 cells/mm3, 32.33 %, g/dL, 9.67 x 104 cells/mm3, 67.33 mg/dL, and total serum protein of 3.10 mg/dL, respectively. Moreover, the diet improved special growth rate, feed conversion ratio, feed efficiency and the survival rate of catfish. The hematological and physiological profile of catfish improvement are considered to be due to the content of secondary metabolites of FMH, namely curcuminoids, vitamin C, essential oils, tannins, and flavonoids, which trigger immunostimulation. The presence of curcuminoids provide an antioxidant effect on cell membranes reducing erythrocyte cell membrane damage due to oxidation. Similarly, flavonoids are natural antioxidants, which are credited with the ability of reducing free radicals and anti-free radicals.