Dietary supplementation with <scp>ALLPRO</scp> , a <scp>DHA</scp> source, for Nile tilapia reared under field conditions throughout cold season: Effects on growth performance, carcass and fillet quality, and economic feasibility

Abstract This study evaluated the effects of dietary supplementation with ALLPRO, a source of docosahexaenoic acid (DHA—C22:6n‐3, 126 g kg −1 dry weight) and nucleotides (5 g kg −1 dry weight), on Nile tilapia farmed in southern Brazil during autumn, winter, and spring. Two isoenergetic diets were tested: one supplemented with 1.7 g ALLPRO 100 g −1 of diet (dry weight), based on prior studies performed under lab conditions, and a control diet without n‐3 polyunsaturated fatty acids (PUFAs). Juvenile tilapia (16.09 ± 0.13 g) were stocked at 45 fish m −3 in 12 net cages (1.6 m 3 ) placed in a pond. A completely randomized design with six replicates per treatment was used. Feeding rate and frequency were adjusted based on fish biomass and water temperature using Epagri/SC feeding tables. The trial lasted 245 days, and the parameters evaluated included growth performance, yield (fillet and carcass), proximate composition, fillet fatty acid profile, and economic feasibility. Fish fed the ALLPRO diet showed improved feed conversion, highest daily weight gain, increased protein utilization, greater yield, and elevated crude protein and n‐3 PUFA levels, especially DHA, in fillets. Supplementation with 0.22 g of DHA 100 g −1 of diet dry weight resulted in a 10% higher final weight compared to fish fed the control diet without DHA supplementation. Although the inclusion of the additive increased the diet cost, the average production cost per whole fish and fillet was more economically efficient. In conclusion, ALLPRO supplementation enhanced growth, nutritional quality, and economic feasibility in Nile tilapia farming under suboptimal temperatures in field conditions.