Effect of papaya leaf extract inclusion on growth performance and haematological parameters of red hybrid tilapia, Oreochromis mossambicus × Oreochromis niloticus fed diets formulated with Hermetia meal and Azolla

Abstract

This research aimed to explore the impact of incorporating papaya leaf extract into diets for red hybrid tilapia prepared with alternative ingredients: black soldier fly larvae (BSFL) and Azolla. Using a 4 x 2 factorial design, eight diets were formulated and fed to the fish in triplicate for eight weeks. All diets were designed to have similar protein, lipid and energy levels, 40%, 8.5%, and 355 (kJ/100 g), respectively. The study used fish with an average initial weight of 2.29 ± 0.06 g. The results showed that the fish fed with the combination of BSFL and papaya leaf extract had the highest final weight of 31.84 ± 1.32 g, compared to other treatments (p<0.05), except for the basal diet containing papaya leaf extract. The addition of BSFL meal improved growth parameters, but Azolla appeared to have adverse effects. Incorporating 1.95% papaya leaf extract into the formulation also helped enhance growth performance. However, neither alternative ingredients nor papaya leaf extract affected the FCR and PER of the treatment groups. The VSI and HSI of the fish studied were unaltered across the experimental diets. The addition of alternative ingredients and papaya leaf extract to the fish feed did not affect its moisture and protein content. However, papaya leaf extract treatments had a significant impact on the fish's lipid and ash content. The haematological parameters of the experimented fish were generally unaffected by the dietary treatments. However, the levels of leucocytes, HGT, HCT, and erythrocytes were notably lower in all groups treated with papaya leaf extract. except for leucocytes, HGT, HCT and erythrocytes, the levels were significantly lower in all groups treated with papaya leaf extract. The BSFL meal can serve as a viable substitute ingredient in fish feed. However, caution should be exercised when incorporating Azolla. Also, adding 1.95% papaya leaf extract to the practical diet for tilapia, which was prepared using alternative protein sources, can enhances growth performance without any negative impact on the fish's overall well-being.