DINÂMICA NICTIMERAL E VERTICAL DAS CARACTERÍSTICAS LIMNOLÓGICAS EM AMBIENTE DE CRIAÇÃO DE PEIXES EM TANQUES-REDE

O presente trabalho teve como objetivo verificar a dinâmica nictimeral e vertical das características limnológicas em ambiente de criação de peixes nativos em tanques-rede no reservatório da Itaipu Binacional. Os parâmetros avaliados foram temperatura da água, oxigênio dissolvido, condutividade elétrica, pH, fósforo total, nitrito e amônia. Verificou-se que ocorreu variação nictimeral para todos os parâmetros, exceto para amônia e fósforo total. Entretanto, as variáveis estão dentro dos limites recomendados para a aquicultura, com exceção do oxigênio dissolvido, que apresentou valores críticos à noite. Para a distribuição vertical, as concentrações dos parâmetros físicos e químicos da água não ultrapassaram o limite estabelecido pela resolução do CONAMA 357/05 para criação de peixes. No entanto, houve variação vertical para nitrito e fósforo. PALAVRAS-CHAVES: Aquicultura, cultivo intensivo, limnologia, qualidade de água

Eugenol as anesthetic for Piaractus mesopotamicus

The different practices used in fish breeding require intense handling, leading to fish stress. The use of anesthetics is important to overcome this problem. This study aimed at evaluating the impact of eugenol on the induction and anesthetic recovery of Piaractus mesopotamicus from different weight classes. An experiment was carried out in a 5x5 factorial scheme, consisting of five weight classes (50 ± 5.61 g, 100 ± 9.36 g, 150 ± 12.29 g, 200 ± 12.73 g and 250 ± 18.77 g) and five eugenol concentrations (40 mg L-1, 80 mg L-1, 120 mg L-1, 160 mg L-1 and 200 mg L-1). The anesthesia induction was divided into four stages, according to the behavior of the anesthetized fish, being the duration of each stage recorded, and the desensitization moment and recovery time evaluated. A quadratic effect was observed at the anesthetic induction time, i.e., when the dose increased, the induction time decreased, tending to stabilize for increasing doses. The best results for anesthetic induction were observed at the 175 mg L-1, 208 mg L-1, 203 mg L-1, 240 mg L-1 and 225 mg L-1 concentrations, respectively for the 50 g, 100 g, 150 g, 200 g and 250 g weight classes. No interaction between the shortest induction time and the shortest recovery time was observed. Thus, the doses which provided a lower induction time for the weight classes range between 175 mg L-1 and 240 mg L-1

Performance parameters of juvenile pacu fed at different feeding frequencies in net cages

O objetivo deste trabalho foi avaliar o desempenho zootécnico e as características bromatológicas e hematológicas de pacus alimentados a diferentes frequências de arraçoamento. Três mil e duzentos peixes, com peso inicial médio de 65,9±2,36 g, foram distribuídos em 16 tanques‑rede de 5 m3 de volume útil. Durante 65 dias, foram avaliadas quatro frequências de arraçoamento (tratamentos): T1, às 12:00 h; T2, às 8:00 e às 17:00 h; T3, às 8:00, 12:00 e 17:00 h; e T4, às 8:00, 11:00, 14:00 e 17:00 h. Utilizou-se o delineamento experimental inteiramente casualizado, com quatro repetições. Analisaram-se parâmetros de desempenho produtivo, índices de gordura visceral e hepatossomático, composição centesimal da carcaça e parâmetros hematológicos e bioquímicos. Quanto ao ganho de peso, as frequências T3 e T4 proporcionaram melhores resultados do que T1 e T2. Embora a proteína, o colesterol e os eritrócitos tenham apresentado diferenças entre os tratamentos, permaneceram dentro dos valores de referência para pacus cultivados em tanques‑rede. A frequência de três arraçoamentos diários resultou em maior ganho de peso, em comparação aos demais tratamentos, sem interferir na saúde e na composição centesimal das carcaças dos animais.The objective of this work was to evaluate the performance parameters and the chemical composition, and the hematologic characteristics of pacu fed at different feeding frequencies. Three thousand two hundred fish, with 65.9±2.36 g initial weight, were distributed in 16 net cages with 5 m³ total volume. During 65 days, four feeding frequencies (treatments) were evaluated as follows: T1, at 12:00 h; T2, at 8:00 and 17:00 h; T3, at 8:00, 12:00, and 17:00 h; and T4, at 8:00, 11:00, 14:00, and 17:00 h. A completely randomized experimental design was used with four replicates. Performance parameters, visceral‑somatic fat and hepatosomatic indexes, carcass proximate composition, and hematological and biochemical parameters were analyzed. For weight gain, T3 and T4 frequencies provided better results than T1 and T2. Although protein, cholesterol and erythrocytes have shown differences between treatments, they remained within the default reference range for pacus reared in net cages. The frequency of  three daily feeds, resulted in better weight gain, in comparison to the other treatments, without interfering in animal health and in the proximate composition of animal carcass

Protein hydrolysates in diets for juvenile dourado, Saminus brasiliensis

A exigência de alimento proteico palatável e de alto valor nutricional torna a dieta dos peixes carnívoros altamente dependente de farinha de peixe [FP], alimento de alto custo e já escasso no mercado. Hidrolisados de subprodutos da indústria animal são alimentos de alta qualidade que podem ser usados para substituir a FP nas dietas para peixes. Este trabalho foi realizado em dois ensaios: o primeiro avaliou a digestibilidade de hidrolisados de resíduos de tilápia [RTI], cabeças de atum [CAT], fígados de suínos [FSU] e de aves [FAV] e a influência da inclusão dos hidrolisados nas dietas no perfil de enzimas digestivas nos estômagos, cecos pilóricos e intestinos de juvenis (39,73 ± 5,30 g) do Characiforme carnívoro dourado, Salminus brasiliensis; o segundo ensaio avaliou o desempenho de juvenis de dourados (4,57 ± 1,25 g) alimentados com níveis crescentes de inclusão de FSU (0, 70, 140, 210 e 280 g kg-1) na dieta. A inclusão dos hidrolisados na formulação das dietas diminuiu o pH das rações mas não interferiu no consumo pelos peixes. Os maiores coeficientes de digestibilidades dos nutrientes foram registrados em peixes alimentados com as dietas contendo RTI e FSU, enquanto os menores foram encontrados para aqueles alimentados com as dietas contendo CAT. A atividade da protease e da lipase foi maior nos estômagos dos animais, em especial aqueles que foram alimentados com a dieta contendo FSU. A atividade de amilase foi maior nos cecos pilóricos, enquanto nos intestinos foi registrada maior atividade nas dietas controle e RTI. Hidrolisados de subprodutos da indústria animal foram altamente digestíveis para dourados e o perfil enzimático dos peixes foi dependente dos nutrientes da dieta. No segundo ensaio os menores valores de ingestão diária foram registrados nos peixes alimentados com a dieta sem inclusão de hidrolisado, mas os menores valores de ganho de peso, peso final e das taxas de crescimento específico, de eficiência proteica e energética, e de retenção proteica foram registrados nos peixes alimentados com a dieta contendo 280 g kg-1 de hidrolisado suíno. A grande proporção de aminoácidos livres e pequenos peptídeos nas dietas com inclusões acima de 140 g kg-1 do produto aparentemente reduziu a síntese de proteínas dos animais. A saúde dos peixes não foi afetada significativamente pela inclusão de hidrolisados na dieta, porém, aparentemente, os peixes alimentados com dietas contendo até 140 g kg-1 de hidrolisado tiveram melhores índices imuno-hematológicos.Carnivorous fish diets strongly depend on fish meal (FM), a high-cost, scarce feedstuff, given the need for palatable protein and high nutritious value. Animal by-product hydrolysates are high-quality feedstuff that can substitute FM in fish diets. This study evaluated digestibility of hydrolysates from tilapia residue [TR], tuna head [TH], swine liver [SL] and poultry liver [PL], and the profile of digestive enzymes in the stomachs, pyloric cecum and intestines of juvenile (39,73 ± 5,30 g) dourado, Salminus brasiliensis, a carnivorous Characin fed diets containing graded levels of hydrolysates, and the performance of juvenile dourado (4,57 ± 1,25 g) fed diets containing increasing levels of FSU (0, 70, 140, 210 and 280 g kg-1). The addition of hydrolysates to diets lowered the pH of feed, but did not alter feed intake by fish. Higher digestibility coefficients of nutrients were recorded for fish fed diets containing TR and SL, and the lower for those fed diets containing TH. Protease and lipase activity in the fish\'s stomach was higher, especially for those fed diets containing SL. Amylase activity was higher in pyloric caeca, while in the intestines the higher activity was registered for fish fed control and TR diets. Animal by-product hydrolysates were highly digestible for dourado, and enzymatic profile of fish depended on nutrients of diets. In the second trial, the lowest values of daily intake were recorded for fish fed diet without inclusion of hydrolysate. However, the lowest weight gain, final weight and specific growth rate, protein and energy efficiency, and protein retention rates were recorded for fish fed diet with 280 g kg-1 of swine hydrolysate. The large proportion of free amino acids and small peptides in the diets with inclusions above 140 g kg-1 of the product apparently reduced the protein synthesis by fish. Health status of fish was not significantly affected by dietary hydrolysates, but apparently, fish fed diets containing more than 140 g kg-1 had better immuno-hematological indices

Digestibility and pricing of Chlorella sorokiniana meal for use in tilapia feeds

Several microalgae contain in excess of 50 % crude protein with amino acid profile comparable to that of fish meal. In addition, high polyunsaturated fatty acid contents encourage their use in animal feeding and nutrition, particularly in the formulation and processing of aquafeeds. This study aims at estimating the feasibility of Chlorella meal as feed ingredient for the feeding and nutrition of farmed tilapia based upon digestibility data. Juvenile tilapia were stocked in conical-bottomed tanks (200 L) with superficial, continuous water flow, and fed to apparent satiation in three daily meals with a reference diet and a test diet containing 30 % lyophilized Chlorella sorokiniana added of an inert marker. Feces were collected overnight by sedimentation in refrigerated, plastic containers coupled to the tanks and analyzed for determination of chemical composition and inert marker contents to estimate apparent digestibility coefficients (ADCs) of protein and energy of Chlorella meal; registered ADCs of Chlorella meal were 90.5 and 84.22, respectively. A pricing model considering the quantity of digestible nutrient was proposed based on ADCs of Chlorella and compared with the price of fishmeal (FM) and soybean meal (SBM). The indicative prices to elicit the use of Chlorella as a protein source rather than FM or SBM for the feed and nutrition of tilapia were 2.65 USD kg−1 and 0.66 USD kg−1, respectively

Fish and fishery products trade in Brazil, 2005 to 2015: A review of available data and trends

Along the last ten years fish and fishery product trade in Brazil has been on a downward trajectory turning a profit of US$98.6 million in 2005 into a loss of US$ 1.25 billion by 2014. On the other hand, the country is a leading producer of grains and has the third largest animal feed industry in the world, which has added 5.5 million hectares of freshwater reservoirs and 3.5 million km2 of an exclusive marine economic zone in the same period, a sizable potential for development of the aquaculture industry. This study aims at unveiling strategies for the reduction of the deficit in the Brazilian seafood trade balance, based on critical analysis of the quantitative and qualitative characteristics of imported fishery products. The fish and fishery product trade in Brazil, from 2005 to 2015, was studied considering import and export data mined from the Brazilian Ministry of Development, Industry and Commerce databases through the Aliceweb system, and clustered as follows: processing; product species; origin; conservation; and group. The main imported products were gutted fresh fish, highest price (salmon); salted dried fish, higher price (cod); frozen fish fillets, lowest price (fish and hake). The replacement of fish imports by domestic production is not enough to enable consumers to identify the equivalence between products (technical, qualitative or organoleptic). Developing strategies for the production of fish and fishery products at competitive prices and quantities that meet consumer demand is an immediate need, and the development of the aquaculture industry a rational strategy

DIEL AND VERTICAL DYNAMIC OF LIMNOLOGICAL CHARACTERISTICS IN FISH REARING NET-CAGES ENVIROMENT DINÂMICA NICTIMERAL E VERTICAL DAS CARACTERÍSTICAS LIMNOLÓGICAS EM AMBIENTE DE CRIAÇÃO DE PEIXES EM TANQUES-REDE

<p>This study aimed to verify the diel and vertical dynamic characteristics in limnological environment for rearing native fish in net-cage at the reservoir of Itaipu Binacional. The parameters evaluated were water temperature, dissolved oxygen, electrical conductivity, pH, phosphorus, nitrite and ammonia. It was found that there was diel variation for all parameters, except for ammonia and phosphorus. But the variables are in the recommended limits for aquaculture, with the exception of dissolved oxygen that showed critical rates at night. For the vertical distribution concentrations of physical and chemical parameters of water did not exceed the limit established by CONAMA Resolution 357/05 for fish rearing, however, there was vertical variation for nitrite and phosphorus.</p><p>KEY WORDS: Aquaculture, intensive culture, limnology, water quality.</p> <p>O presente trabalho teve como objetivo verificar a dinâmica nictimeral e vertical das características limnológicas em ambiente de criação de peixes nativos em tanques-rede no reservatório da Itaipu Binacional. Os parâmetros avaliados foram temperatura da água, oxigênio dissolvido, condutividade elétrica, pH, fósforo total, nitrito e amônia. Verificou-se que ocorreu variação nictimeral para todos os parâmetros, exceto para amônia e fósforo total. Entretanto, as variáveis estão dentro dos limites recomendados para a aquicultura, com exceção do oxigênio dissolvido, que apresentou valores críticos à noite. Para a distribuição vertical, as concentrações dos parâmetros físicos e químicos da água não ultrapassaram o limite estabelecido pela resolução do CONAMA 357/05 para criação de peixes. No entanto, houve variação vertical para nitrito e fósforo.</p><p>PALAVRAS-CHAVES: Aquicultura, cultivo intensivo, limnologia, qualidade de água.</p&gt

Feeding rate for pacu reared in net cages

The objective of this study was to evaluate the feeding management of pacu juveniles (P. mesopotamicus) under different feeding rates and its relation with productive performance, body composition and hematological characteristics. A total of 300 fish with initial weight of 84.75±4.52 g were distributed in a completely randomized design composed of four treatments (100, 90, 80 and 70% of feed supply) and five repetitions. The amount of feed was stipulated according to the quantity supplied in the treatment until apparent satiation (100%) of the day before. The decrease in the feeding rate to 70% over satiation apparently improves the apparent feed conversion without harming performance, body composition or biochemical and hematological characteristics of pacu juveniles reared in net cages. © 2012 Sociedade Brasileira de Zootecnia

Digestibility and pricing of Chlorella sorokiniana meal for use in tilapia feeds

ABSTRACT: Several microalgae contain in excess of 50 % crude protein with amino acid profile comparable to that of fish meal. In addition, high polyunsaturated fatty acid contents encourage their use in animal feeding and nutrition, particularly in the formulation and processing of aquafeeds. This study aims at estimating the feasibility of Chlorella meal as feed ingredient for the feeding and nutrition of farmed tilapia based upon digestibility data. Juvenile tilapia were stocked in conical-bottomed tanks (200 L) with superficial, continuous water flow, and fed to apparent satiation in three daily meals with a reference diet and a test diet containing 30 % lyophilized Chlorella sorokiniana added of an inert marker. Feces were collected overnight by sedimentation in refrigerated, plastic containers coupled to the tanks and analyzed for determination of chemical composition and inert marker contents to estimate apparent digestibility coefficients (ADCs) of protein and energy of Chlorella meal; registered ADCs of Chlorella meal were 90.5 and 84.22, respectively. A pricing model considering the quantity of digestible nutrient was proposed based on ADCs of Chlorella and compared with the price of fishmeal (FM) and soybean meal (SBM). The indicative prices to elicit the use of Chlorella as a protein source rather than FM or SBM for the feed and nutrition of tilapia were 2.65 USD kg−1 and 0.66 USD kg−1, respectively