Effect of Tryptophan Supplementation in Commercial Feed on the Growth Performance of Mutiara Catfish Juveniles (Clarias gariepinus)

Abstract

Background: Fish feed requires essential amino acids for optimal protein synthesis, and tryptophan supplementation at appropriate levels can improve growth performance, feed efficiency, and stress tolerance in juvenile fish while excessive or deficient levels can impair growth and health. Aims: To determine the effect of tryptophan supplementation on growth parameters, FCR, PER, and protein retention, as well to identify the optimal dose of tryptophan supplementation in commercial feed for the growth of juvenile Mutiara catfish Study Design: This research used an experimental method with a completely randomized design (CRD) in 4 treatments and 4 replications. The treatments given in this study consisted of treatment A (0%), treatment B with the addition of 0.15%, treatment C with the addition of 0.3% and treatment D with the addition of 0.45%. Place and Duration of Study: This research was conducted form December 2025 to March 2026, at the Hatchery Building 4, Faculty of Fisheries and Marine Sciences, Padjadjaran University. Methodology: The research subjects were juvenile Mutiara catfish (Clarias gariepinus) measuring 10–13 cm. The fish were reared in aquariums (40 × 24 × 25 cm) at a stocking density of 4 fish per aquarium. Acclimatization in the aquariums lasted 14 days. During the rearing period, the fish were fed a diet supplemented with tryptophan using the coating method. Feeding was conducted twice daily at 08:00 and 16:00 WIB. The feed was provided was 5% of the fish biomass, and the feeding rate was adjusted weekly based on the fish biomass weight. Data were analyzed using ANOVA, followed by Duncan’s Multiple Range Test at a 95% confidence level. Results: Tryptophan supplementation in commercial feed significantly enhanced the growth of juvenile Mutiara catfish with treatment C with the addition of 0.3% tryptophan, resulting in absolute weight gain (222.70 g), FCR (1.46), PER (11.75%), and protein retention (51.25%). Conclusion: Tryptophan supplementation has been shown to increase weight gain, decrease the protein conversion ratio (FCR), increase the protein efficiency ratio (PER), and increase protein retention. The optimal tryptophan supplementation dose was found in to be 0.3% of the total diet (Treatment C).