Abstract: Background and Objective: At present, Fish Meal (FM) and meat meal are the dominant animal protein sources for livestock feeds. However, these protein sources are not affordable for most livestock farmers, especially those in developing countries. Thus, it would be helpful to test other protein-based animal byproducts as alternative cheaper protein sources and as a solution to the overdependence of animal feeds on FM. The present study was undertaken to investigate the feasibility of replacing fish meal (FM) with chicken feather protein hydrolysate (CFPH) in rat diet. Materials and Methods: The changes in growth performance (after 4 weeks) and some tissue biochemical indices (after 7 weeks) were determined following feeding with iso-proteic and iso-energetic diets, in which 0 (control), 20, 40, 60, 80 and 100% of FM were replaced by CFPH (CFPH 0-100), respectively. Results: Food intake and weight gain showed progressive reduction with increasing proportion of CFPH in the diet increased. The growth parameters monitored were observed to decrease progressively with the increasing CFPH level in the diet. Plasma lipid concentrations were not significantly altered in the rats fed with 20 and 40% CFPH but were significantly lower in the rats fed with 60-100% CFPH compared to the rats fed with 100% FM. Fecal nitrogen excretion and plasma total protein concentration were significantly increased in the rats fed with 40-100% CFPH compared to rats fed 20 and 40% CFPH as well as 100% FM. Liver and kidney function indices monitored were not significantly altered in the rats fed CFPH up to 40% compared to the rats fed 100% FM. Conclusion: Based on the data generated from this study, it could be concluded that the inclusion of CFPH in rat diet up to 20% of the total dietary protein content is safe and has no drastic effect on the growth performance. Thus, feeding CFPH to animals could be a cost-effective solution to the challenge of waste feather disposal and could reduce the overdependence of livestock feed on FM, thereby ensuring sustainable livestock farming.