Effects of Fish Discards as a Substitute for Fish Meal on the Growth Rates and Health Status of Oreochromis niloticus

Discards decrease natural resources and harm the viability of fisheries. The current experiment was conducted to determine the suitability of fish discards for cultivating the Nile tilapia (Oreochromis niloticus) and their effecton growth rates and the health condition of the fish. 300 healthy live Nile tilapia specimens were obtained  and divided into five equal groups, coded as 0, 25, 50, 75, and 100% DF diets. The experiment lasted for 60 days. All growth performance parameters revealed no discernible difference between fish fed 0 (control group) and 100% DF diets. Fish fed 75% DF diet recorded the best significant feed conversion rate of 1.1± 0.4. Fish fed 50 and 75% DF diets recorded the highest significant weight gain (25.4± 3.02, 25.3± 2.7g, respectively). The glucose value showed a significant decrease in the 25% DF treatment and an increase in 100% DF treatment, while it showed a non-significant decrease in 50 and 75% DF treatments. This study determined that the haematological values remained acceptable for tilapia production. The present work concluded that fish discards are suitable as dietary protein sources for the Nile tilapia; it contributed significantly to fisheries' sustainability and the Nile tilapia feeding cost reduction.