Comparative effects of phytogenic feed additives on growth and feed efficiency in Nile tilapia

Aquaculture is challenged by the rising cost of feed and sustainability issues. Hence, this study aimed to evaluate the effects of phytogenic feed additives on growth performance and feed efficiency in Nile tilapia (Oreochromis niloticus). Ninety fingerlings (average initial weight 5.2 ± 0.3 g) were distributed into three treatments: control feed, scent leaf diet (10% inclusion), and bitter leaf diet (10% inclusion), and fed for over 60 days. Proximate analysis showed comparable protein levels across diets (31.8 ± 0.6% to 32.5 ± 0.4%), while phytochemical screening revealed higher concentrations of alkaloids (18.7 ± 0.8 mg/100 g), flavonoids (32.1 ± 1.5 mg/100 g), and tannins (20.4 ± 0.9 mg/100 g) in bitter leaves compared to scent leaves. Growth performance indicated that fish fed bitter leaves achieved the highest final mean weight (16.2 ± 0.8 g), followed by scent leaves (13.4 ± 0.7 g), while the control group recorded the lowest (9.2 ± 0.5 g). Feed conversion ratio (FCR) was most efficient in the bitter leaf group (38.1 ± 1.5%), compared to scent leaves (49.7 ± 1.8%) and control feed (67.4 ± 2.3%). Although statistical analysis showed no significant differences (p > 0.05), the consistent numerical advantages of bitter leaf diets highlight their potential as sustainable feed additives. The study shows that bitter leaves promote better growth and feed utilization in Nile tilapia, offering ecological and economic benefits for aquaculture. It is recommended that future research explore long‑term impacts and commercial scalability of phytogenic feed additives.