Mansoura Veterinary Medical Journal

Effects Of Dietary L-Tryptophan On Growth Performance, Feed Utilization, And Protein Metabolism In Nile Tilapia (Oreochromis Niloticus)

Israt Mishu, Department of Biological Sciences, Purdue University Fort Wayne, Fort Wayne, Indiana, USA
Lindee Mason, Department of Biological Sciences, Purdue University Fort Wayne, Fort Wayne, Indiana, USA
Ahmed Mustafa, Department of Biological Sciences, Purdue University Fort Wayne, Fort Wayne, Indiana, USAFollow

Document Type

Original Article

Keywords

L-tryptophan; Nile tilapia; growth performance; stress regulation; feed utilization; aquaculture

Abstract

This research examines the impact of dietary L-tryptophan supplementation on growth performance, feed efficiency, and protein metabolism in Nile tilapia (Oreochromis niloticus) under stress and non-stress settings. This experiment evaluated essential growth metrics, encompassing weight gain, length gain, specific growth rate, feed conversion ratio, and protein energy retention. Nile tilapia were categorized into four experimental groups: a control group on a commercial diet, a control group supplemented with L-tryptophan (0.33%/kg feed), a stress-induced group receiving cortisol (0.02%/kg feed), and a stress-induced group receiving both cortisol (0.02%/kg feed) and L-tryptophan supplementation (0.33%/kg feed). The findings indicated that Ltryptophan supplementation significantly enhanced weight, length, specific growth rate, and feed conversion ratio in unstressed fish, fed with the supplemented diet. Fish exposed to stress without L-tryptophan supplementation exhibited considerable declines in growth, signifying stress-induced metabolic disturbances. The stressinduced group receiving L-tryptophan exhibited moderate enhancements in growth parameters, mentioned above, indicating that L-tryptophan partially mitigates the adverse effects of stress but does not completely restore normal growth. Protein energy retention was consistent across all groups, suggesting that L-tryptophan alone does not substantially influence protein deposition. The findings underscore the potential of dietary L-tryptophan supplementation to improve growth performance and feed efficiency in unstressed Nile tilapia, while providing partial alleviation of stressinduced growth inhibition.

How to Cite This Article

Mishu, Israt; Mason, Lindee; and Mustafa, Ahmed (2025) "Effects Of Dietary L-Tryptophan On Growth Performance, Feed Utilization, And Protein Metabolism In Nile Tilapia (Oreochromis Niloticus)," Mansoura Veterinary Medical Journal: Vol. 26: Iss. 2, Article 1.
DOI: https://doi.org/10.35943/2682-2512.1254