A kombucha-enriched diet positively impacts the growth, nutrient utilization and intestinal microbes of striped catfish (Pangasius hypophthalmus)

This study aims to compare the effectiveness of kombucha supplementation in the different protein diets on striped catfish (Pangasius hypophthalmus) growth performance increasing. The study was conducted experimentally using a two-factorial Complete Randomized Design. The first factor (P) was different protein diets (28% and 39%), while the second factor (K) was without and with kombucha addition. A total of 400 catfish seeds were divided into four different dietary treatments, including low protein diet (± 28%) without kombucha (PaKa), low protein diet with kombucha (PaKb), high protein diet (± 39%) without kombucha (PbKa), and high protein diet with kombucha (PbKb). The fish was reared for 40 days, and their body weight was measured every 10 days. The present study showed that the addition of kombucha to different protein diets had a significant effect on the growth rate of catfish. Giving kombucha on a high protein diet (PbKb) generated the best results on the specific growth rate of catfish (2.46 ± 0.15%), protein retention (52.43 ± 5.73%), the number of intestinal microbes (2.09 × 10⁶ CFU/mL), and intestinal villi length (55.15 ± 1.09 µm). The highest feed efficiency was also obtained in the PbKb treatment by showing the lowest feed conversion ratio (1.18 ± 0.14) among other treatments. In this study, it was also found that providing kombucha in low protein feed (PaKb) significantly increased the growth rate of striped catfish compared to the PaKa treatment but did not differ significantly from the PbKa treatment. Based on this study, it can be concluded that combining kombucha and high-protein feed can be recommended to increase the productivity of catfish farming. Furthermore, as a solution to the high price of high protein feed, adding kombucha in low protein diet can be applied in catfish farming to optimize its growth performance.