Résumé:
This study aimed to valorize marine by-products through the extraction of astaxanthin from red shrimp (Aristeus antennatus) waste and the production of fishmeal from mixed fish residues, to evaluate their effects on the growth performance and nutritional quality of Nile tilapia (Oreochromis niloticus). Fish waste collected from local fisheries was processed into fishmeal, while shrimp by-products were subjected to acetone extraction for pigment recovery. The nutritional composition of the fishmeal was evaluated (protein, lipid, and carbohydrate contents), and the astaxanthin content of the shrimp powder was assessed. Three experimental diets were formulated: a commercial control diet, a fishmeal-based diet, and a fishmeal diet enriched with 10% astaxanthin. The feeding trial lasted for 21 days, during which growth parameters (length and weight) and nutritional composition (proteins, lipids, carbohydrates) were evaluated. The fishmeal production yield was 17.05%, containing 29.14% proteins, 9.62% lipids, and 2.86% carbohydrates, demonstrating its nutritional suitability as a feed ingredient. The extraction of astaxanthin from shrimp waste resulted in a 5.15% yield, with a concentration of 11.04 mg β-carotene equivalent/100 g. Tilapia fed the diet composed with fishmeal enriched with 10% astaxanthin showed the best growth performance, with an average length of 8.28 cm and weight of 9.85 g. Nutritionally, the fish receiving waste-based diets including astaxanthin exhibited higher protein (7.82%) and lipid (3.23%) levels, with stable carbohydrate content (4.63%).
