Received: Dec 25, 2025 / Accepted: Feb 25, 2026 / Published: Jun 30, 2026
This study evaluated the effects of dietary supplementation with a fermented betel leaf preparation on the growth performance, feed utilization, and resistance to Aeromonas veronii infection in common carp (Cyprinus carpio). A six-week feeding trial was conducted using four diets: PF0 (control), PF2 (2 g kg-1), PF5 (5 g kg-1), and PF10 (10 g kg-1). After the feeding period, fish were challenged with A. veronii, and the cumulative mortality rates were recorded over 14 days to assess disease resistance. The results showed that supplementation at 10 g kg-1 significantly enhanced growth performance, while the feed utilization indices did not differ among treatments. Survival during the feeding period remained 100%, indicating that the fermented preparation was safe for fish. The PF10 group exhibited the lowest cumulative mortality (22.73%), followed by PF5 (35.38%), with both values significantly lower than the control (46.67%), demonstrating the immunoprotective potential of the fermented product. Overall, the findings indicate that the dietary inclusion of fermented betel leaves, especially at 10 g kg-1, can improve growth, maintain the feed conversion ratio, and enhance resistance to A. veronii infection in common carp, contributing to safer and more sustainable aquaculture practices.
