Evaluation of Sargassum spp. Meal Inclusion in Diets for Prejuvenile Nile Tilapia

This preliminary study evaluated dietary inclusion of Sargassum spp. meal in feeds for prejuvenile Nile tilapia (Oreochromis niloticus) through method-specific feed characterization and a 67-day feeding trial. Two experimental diets containing 10% and 15% Sargassum spp. meal were compared with a commercial reference feed using 54 fish distributed among nine aquaria, with three independent aquaria per treatment and six fish per aquarium. The Sargassum spp. meal contained 4.24 ± 0.19 g/100 g moisture and 37.41 ± 0.91 g/100 g ash on the as-analyzed gravimetric basis. NIRS-based feed protein estimates were 52.62 ± 0.15, 53.35 ± 0.31, and 54.44 ± 0.46 g/100 g of scanned material for the 10%, 15%, and commercial diets, respectively. Gravimetric and NIRS outputs were generated from separate aliquots and method-specific reporting bases and were therefore not interpreted as a common wet-weight mass balance. At day 67, aquarium-level final body weight was 59.90 ± 12.31 g, 68.56 ± 3.83 g, and 57.15 ± 4.33 g in the 10%, 15%, and commercial treatments, respectively. One-way ANOVA based on aquarium means detected no treatment effect on final body weight [F(2,6) = 1.724, p = 0.256] or final total length [F(2,6) = 1.597, p = 0.278]. The 15% diet showed numerically higher weight gain and SGR and a lower FCR, but confidence intervals were wide, and the differences were not statistically significant. These results support only the preliminary short-term feasibility of the tested formulations; they do not establish equivalence, superiority, complete nutritional adequacy, or consumer safety. Confirmation requires greater experimental replication and characterization of digestibility, amino acids, minerals, iodine, arsenic, antinutritional factors, and tissue bioaccumulation.