Dias, Danielle de CarlaFurlaneto, Fernanda de Paiva BadizSussel, Fábio RosaTachibana, LeonardoGonçalves, Giovani SampaioIshikawa, Carlos MassatoshiNatori, Mariene MiyokoRanzani-Paiva, Maria José T.2024-05-172024-05-1720201807-8672S1807-86722020000100102-scl10.4025/actascianimsci.v42i1.47960https://repositorio-aptaregional.agricultura.sp.gov.br/handle/123456789/1938ABSTRACT. This work examines the economic advantages of probiotic use in the diet of Nile tilapia broodstock during the reproductive period. For this purpose, Bacillus subtilis was applied as a feed additive. The experimental design was completely randomized with three treatment groups: the T0 control (without probiotic), the T1 continuous probiotic intake, and the T2 alternate probiotic intake at a dose of 0.50 g kg-1 of feed (1010 CFU g-1) with four replicates. For the reproduction assay, 118 females and 48 males of Nile tilapia (proportion 4 males:9 females. hapa-1) (weight 527.65 g ± 185.98 g and length 30.16 cm ± 3.57 cm) were distributed into 12 hapas (3.5 × 2.0 × 1.5 m). Reproductive variables (spawning female percentage, egg production, and fry production) were used to calculate the economic feasibility indexes (total cost of nutrition [TcN], gross revenue [GR], and total operational profit [ToP]). The results show increasing values for spawning female number, collected eggs, and surviving fry in the probiotic groups. We recommend continuous intake of probiotic (feed with addition of probiotic) at a dose of 0.5 g kg-1 of feed (1010 CFU g-1) during the breeding season of Nile tilapia, due to the suitable reproductive indexes and profitability.Bacillus subtilisfish farmingfeed additiveprofitabilityspawningArtigos