AQUEOUS ALMOND (TERMINALIA CATAPPA) LEAF EXTRACT ENHANCED GROWTH PERFORMANCE, IMMUNOCOMPETENCE AND RESISTANCE OF HETEROBRANCHUS LONGIFILIS TO PSEUDOMONAS AERUGINOSA

Abstract

The growth, survival, oxidative stress and resistance of Heterobranchus longifilis fingerlings to Pseudomonas aeruginosa after receiving dietary Terminalia catappa extract for 10 weeks were investigated. Five diets; AL1 (no extract, control), AL2 (0.5% ethanolic extract), AL3 (1.0% ethanolic extract), AL4 (0.5% aqueous extract) and AL5 (1.0% aqueous extract) of T. catappa were allotted triplicate groups of H. longifilis (3.82± 0.05 g) for 70 days. Results shows higher concentrations of
total phenolics, tannins, alkaloids and flavonoids were observed in ethanol extracts than aqueous extracts. Feed intake significantly (P<0.05) reduced in fish fed ethanol extract, with mean weight gain significantly (P<0.05) high in AL1 (22.06 g), AL5 (21.87 g) and AL4 (20.20 g), while the least value was recorded in AL2 (14.13 g). Hematocrit values significantly reduced in AL2 and AL3, while the lowest value of haemoglobin was recorded in AL3. Higher values of glutathione S-transferase (GST) and superoxide dismutase (SOD) were observed in AL4 and AL5. Survival ranged from 83.67% in
AL3 to 95% in AL5. The relative percentage survival (RPS) ranged from 20% in AL1 to 90% in AL5 after the challenge with Pseudomonas aeruginosa. This study shows that extraction using water as solvent of almond leaves (T. catappa) conferred more benefits in terms of growth, improved immune system and resistance to virulent A. aeruginosa.