ENHANCED GROWTH AND FEED EFFICIENCY AND REDUCED SERUM GLUCOSE AND HDL-CHOLESTEROL IN NILE TILAPIA Oreochromis niloticus FED DIETS SUPPLEMENTED WITH Sargassum fulvellum

A feeding trial using 225 juvenile Nile tilapia Oreochromis niloticus (1.89±0.62 g) fed five iso-lipidic (8.9%) and iso-nitrogenous (38.3%) diets with Sargassum fulvellum meal (SFM) level of 0% for both positive (PC) and negative control (NC), and incremental levels of 3% (C3), 6% (C6) and 9% (C9) was conducted for 8 weeks. The main objective of the study was to evaluate S. fulvellum as a low level feed supplement for O. niloticus juveniles.  Results showed improved growth performance in fish fed diets supplemented with SFM, with significantly highest performance (P < 0.05) at C6. Feed utilization efficiency increased in juveniles fed diets supplemented with SFM. However, there were no significant differences (P > 0.05) found in the serum uric acid, triglyceride, creatinine, cholesterol, glutamic-pyruvic transaminase, and glutamic oxaloacetic transaminase. On the other hand, serum glucose and high density lipoprotein cholesterol values were significantly reduced (P < 0.05) in fish fed diets supplemented with SFM. Carcass crude fat and protein values were also significantly affected (P < 0.05). HSI values of fish significantly increased (P < 0.05) with supplementation, while VSI values of fish fed diet with SFM supplementation were not significantly different (P > 0.05) from fish fed PC and NC. Moreover, condition factor of juveniles increased with supplementation. Vacuolar degeneration due to lipid accumulation was evident in the livers of fish fed all treatments. Overall, SFM (low level supplementation) is shown to be a potential aquafeed ingredient for juvenile tilapia.