Objetivou-se com este trabalho obter investimento de implantação de uma piscicultura com 27 ha de lâmina d'água ecusto de produção de espécies nativas em sistemas de policultivo e monocultivo, de forma analisar economicamente a viabilidade do sistema de produção. A piscicultura foi implantada no estado de Mato Grosso onde foram construídos três tanques, dois com 6,2 e 11,0 ha de lâmina d'água que foram utilizados em seu primeiro ciclo de produção em sistema de policultivo com Tambatinga, Pintado da Amazônia e Piauçu, e um tanque de 9,8 ha usado com monocultivo de Matrinxã. Foram coletados dados mensalmente in locodos itens de investimentos, despesas e controle Palavras-chave: indicadores zootécnicos. peixe redondo. surubim. viabilidade econômica.

-Performance and economic indicators of a large scale fish farm that produces round fish, located in Mato Grosso State, Brazil, were evaluated. The 130.8 ha-water surface area was distributed in 30 ponds. Average total production costs and the following economic indicators were calculated: gross income (GI), gross margin (GM), gross margin index (GMI), profitability index (PI) and profit (P) for the farm as a whole and for ten ponds individually. Production performance indicators were also obtained, such as: production cycle (PC), apparent feed conversion (FC), average biomass storage (ABS), survival index (SI) and final average weight (FAW). The average costs to produce an average 2.971 kg.ha -1 per year were: R$ 2.43, R$ 0.72 and R$ 3.15 as average variable, fixed and total costs, respectively. Gross margin and profit per year per hectare of water surface were R$ 2,316.91 and R$ 180.98, respectively. The individual evaluation of the ponds showed that the best pond performance was obtained for PI 38%, FC 1.7, ABS 0.980 kg.m -2 , TS 56%, FAW 1.873 kg with PC of 12.3 months. The worst PI was obtained for the pond that displayed losses of 138%, FC 2.6, ABS 0.110 kg.m -2 , SI 16% and FAW 1.811 kg. However, large scale production of round-fish in farms is economically feasible. The studied farm displays favorable conditions to improve performance and economic indicators, but it is necessary to reproduce the breeding techniques and performance indicators achieved in few ponds to the entire farm.

Objetivou-se com este trabalho analisar a viabilidade econômica da implantação de uma piscicultura de grande porte no Estado de Mato Grosso, com 174 ha de lâmina d´água em sistema de tanques escavados, utilizando 30 % dessa área com criação do pintado da Amazônia Pseudoplatystoma spp. e 70 % com criação de peixes redondo (espécies e híbridos do gênero Colossoma e Piaractus). Os dados foram coletados diretamente no setor produtivo, em que estão sendo construídos 73 tanques escavados, com sistemas de abastecimento e drenagem individual. Foram determinados ciclo de criação de 12 meses e os seguintes indicadores zootécnicos, para os peixes redondo e pintado, respectivamente: biomassa de estocagem final média de 0,799 kg/m-2 e de 0,802 kg/m-2, conversão alimentar aparente de 1,80 e 1,90, taxa de sobrevivência de 75 % e de 86 %, peso médio final dos peixes de 1,8 kg e de 2,0 kg. Para obtenção do custo total médio de produção do quilograma dos peixes, foi utilizada a metodologia do custo total de produção (CTP). Para análise de rentabilidade foram utilizados os seguintes indicadores: receita bruta (RB), lucro (L), margem de contribuição (MC), valor presente líquido (VPL), período de retorno do capital (PRC) e taxa interna de retorno (TIR). Para instalação da piscicultura serão investidos R$ 8.688.933,24. O custo total médio do quilograma do peixe, produção total e preço de comercialização dos peixes redondo e do pintado da Amazônia serão, respectivamente: R$ 3,51 e R$ 5,14; 972.797 kg e 418.639 kg, R$ 4,00 e R$ 7,00, o qual totalizará lucro de R$ 1.251.628,29 ao ano (US$ 1= R$ 2,23 cotação média em Julho de 2014). Os resultados do VPL, PRC e TIR para o horizonte de 15 anos são, respectivamente, R$ 7.239.606,49; 4,03 anos e 23,4 %. Foi realizada análise de sensibilidade com diversos cenários desfavoráveis, ainda assim todos apresentaram viabilidade econômica.

This study proposes to investigate whether short restricted-feeding cycles during the pre-fattening phase of tambaqui (Colossoma macropomum) juveniles affect their production performance and yield in a semi-intensive system and if this practice can be introduced as an alternative to reduce production costs in the pre-fattening phase of this species. The fish (8.07 ± 0.07 g) were subjected to short restricted-feeding periods under controlled laboratory conditions (experimental boxes) for 60 days (Phase I). Three feeding strategies were tested, namely: dairy feeding (Control); five days of feeding followed by two days of deprivation (5F/2D); and two days of feeding followed by four days of deprivation (2F/4D). Subsequently, the fish from each treatment (feeding regimes) evaluated in Phase 1 were transferred to an excavated pond with low water exchange and no supplemental aeration (semi-intensive system) where they were fed continuously for 65 days (Phase II). At the end of both phases, performance, metabolic and hematological parameters and the centesimal composition of the filets were analyzed and an economic assessment was undertaken based on the total operating cost (TOC) of production in the different feeding regimes. The restricted-feeding cycles 2F/4D and 5F/2D (Phase I) affected the performance of the fish, which showed lower daily weight gains and specific growth rates (SGR), resulting in lower viscerosomatic index (VSI) and morphometric measurements. However, apparent feed conversion did not differ across the treatments. The feed-deprived fish used triglycerides as an energy source, maintaining their blood glucose levels close to those of the continuously fed group (control). When they started to be feed daily for 65 days (Phase II), the metabolic (triglycerides) and hematological parameters (hematocrit and hemoglobin) equaled those of control group. Nevertheless, their final weight and morphometric measurements were lower than those of non-restricted feed, indicating a partial compensatory growth in tambaqui juveniles. Short restricted-feeding cycles applied in the pre-fattening phase for 60 days negatively affected performance and led to metabolic and hematological alterations in tambaqui (Colossoma macropomum) juveniles. Although these short restricted-feeding cycles resulted in less expenditure on labor and feeding, the fish under those conditions did not develop equally to those fed daily, culminating in less biomass produced during the fattening period in a semi-intensive system for 65 days. Ultimately, this led to a higher total operating cost per gram of produced fish, demonstrating the economic infeasibility of this practice for tambaqui juvenile production.