Pirarucu, Arapaima gigas, is a carnivorous freshwater fish that exists along the Amazon Basin. This study investigated the effect of stocking density on growth performance and economic return of pirarucu in cages. Fish were stocked at densities of 10 or 12.5 fish/m 3 in 4.0-m 3 cages installed in Sítios Novos Reservoir (Ceará State, Brazil), with three replicate cages for each density. Fish were fed a formulated diet containing 40% crude protein and 14.2 MJ/kg of feed and cultured for 140 days. The following physicochemical parameters of the water were always at satisfactory levels for fish culture throughout the experiments: water temperatures ranged from 26.3 to 30.2°C, DO 3.2 to 7.7 mg/L, pH 6.9 to 7.7 and transparency 100 to 130 cm. Survival was high and ranged between 100.0% and 94.7 ± 5.0% in cages at 10 and 12.5 fish/m 3 , respectively. Density significantly affected (P b 0.05) final mean weight (2630.4 ± 213.7 and 2138.0 ± 148.2 g) and weight gain (2516.9±202.0 and 2043.1±142.9 g). In contrast, specific growth rate (2.25±0.09 and 2.22±0.06%/day), feed conversion ratio (1.2±0.1 and 1.2±0.2) and production (26.3±2.1 and 25.4±2.6 kg/m 3 ) were not significantly (P>0.05) affected by stocking density. Economic analysis was emphasized mostly on sales price and pirarucu juveniles and feed costs. The total costs of production were estimated at US$4.52/kg and US$5.31/kg for stocking densities of 10 fish/m 3 and 12.5 fish/m 3 , respectively. At a local market price of US$5.55/kg, the model used suggests that a commercial enterprise can be profitable only for density of 10 fish/m 3 . Furthermore, the economic viability of implementing of pirarucu culture in cages was analyzed using profitability indicators such as internal rate of return (IRR), net present value (NPV) and payback period. The high survival, very fast growth and moderated production rates of pirarucu stocked demonstrate that cages are a viable alternative method to standard ponds for the commercial production of pirarucu. The economic indicators appear to be attractive, thus pirarucu cage culture can become a profitable industry.

The fillet yield and quantity of waste generated after processing are important for planning and evaluating the growth performance of species and systems of aquaculture production in Brazil. The pirarucu (Arapaima gigas) is among the species with desirable characteristics for intensive fish with high market value. The objective was to evaluate the performance of pirarucu fillet in different weight classes: 7.0 to 9.0 kg (group I), 11.0 to 13.0 kg (group II) and 14.0 to 17.0 kg (group III). The fillet yield presented no significant difference between groups. The composition showed significant differences (p < 0.05) for moisture (77.96 to 75.04%) and ash (2.21 to 2.46%), while values of lipid and protein were similar between classes evaluated. In assessing the fat percentage per serving (loin, belly and tail) there was higher fat deposition in the ventral part and in group III. Thus, it can be lessen the pirarucu with weight ranging from 7.0 to 9.0 kg, using shorter production cycles and obtaining better quality fillets by having a lower muscle percentage of lipids.

The effect of salinity on survival, growth, haematological parameters and osmoregulation was evaluated in tambaqui. This study addressed two questions. Firstly, tambaqui (33.9 AE 3.4 g) reared in freshwater were subjected to gradual increases in salinity until 100% mortality. Two daily increments of salinity were tested with three replicates: 1 and 2 g L À1 day À1 , while control group was kept in freshwater. For 1 g L À1 day À1 , the first mortality appeared from a salinity of 11 g L À1 and the last dead fish was observed at a salinity of 20 g L À1 , whereas for 2 g L À1 day À1 , the mortalities occurred only between 20 and 22 g L À1 . The main sub-lethal effects observed were food intake stopped, erratic swimming behaviour, increased mucus production and the dark pattern of pigmentation that appeared at 13 and 16 g L À1 for both treatments. Secondly, juveniles (57.4 AE 6.3 g) were reared at 0, 5, 10 and 15 g L À1 , in triplicate, for 84 days. At the end of the experiment, the results indicated that the survival, growth, haematological parameters and osmoregulatory of fish were significantly affected by salinity. Survival was unaffected by 10 g L À1 , whereas higher salinity (15 g L À1 ) had a detrimental effect. Differences in final weight, specific growth rates (SGR) and mean daily feed intake (MDFI) among treatments were significant. There were no significant trends in feed conversion rate (FCR) at salinities of 0, 5 and 10 ppt. In these salinities, FCR ranged between 1.2 AE 0.1 and 1.3 AE 0.1, whereas FCR at salinity of 15 g L À1 increased to 5.8 AE 4.4. At the end of the experiments, analysis of blood revealed that all haematological parameters were affected by increase in salinity. From the present investigation, it can be concluded that exposure to salinity significantly affects the survival, growth and physiological response of tambaqui.

Endereço para correspondência: Alex Maiorka -amaiorka@ufpr.br R RE ES SU UM MO OExistem vários fatores que podem afetar o desempenho e rendimento dos frangos de corte, independentemente dos níveis nutricionais utilizados nas dietas, como a idade da matriz e o peso do ovo. Neste trabalho, foram avaliados os possíveis efeitos que a idade da matriz e o peso do ovo à incubação exercem sobre o desempenho zootécnico e rendimento de carcaça de frangos de corte. As aves foram distribuídas em um delineamento experimental inteiramente casualizado em esquema fatorial 3 x 3 (ovos provenientes de matrizes de 3 diferentes idades: 30, 48 e 60 semanas, e de 3 categorias de pesos: leves, médios e pesados). As variáveis analisadas foram consumo de ração, ganho de peso e conversão alimentar aos 7, 21, 35 e 42 dias e rendimento de carcaça (rendimento de peito, pernas e gordura abdominal) aos 42 dias de idade. Não houve interação significativa entre os fatores idade da matriz e peso do ovo. Frangos provenientes de matrizes jovens (30 semanas de idade) apresentaram piores resultados de consumo de ração, ganho de peso e conversão alimentar à primeira semana de idade, sendo que este efeito não se mantém até a idade de abate. Houve maior consumo de ração de frangos provenientes de ovos pesados aos 7 dias de idade. Conclui-se que não existe interação entre idade da matriz e peso dos ovos sobre desempenho zootécnico e rendimento de carcaça em frangos de corte. Palavras-chave: fatorial, incubação, matrizes pesadas, rendimento de carcaça. A AB BS ST TR RA AC CT TThere are several factors that can affect the performance and efficiency of broiler, regardless of the levels used in nutritional diets, such as breeder age and egg weight. In this study, were evaluated the effects of breeder age and egg weight carry on the performance and carcass yield of broilers. The birds were allocated in a completely randomized design in a factorial 3 x 3 (eggs from different breeder ages: 30 weeks, 48 weeks and 60 weeks and 3 categories of weights: light, medium and heavy). The variables analyzed were feed intake, weight gain and feed conversion to 7, 21, 35 and 42 days and carcass yield (carcass, chest, legs and abdominal fat) to 42 days old. There was not breeder age interaction for egg weight in broilers. Broilers from young breeders (30 weeks), presented worst results to feed intake, weight gain and feed conversion in first week, but this effect was not maintained until the slaughter age. The feed intake was increased on broilers from light eggs to 7 days old. It was concluded that no exist interaction between breeder age and egg weight on performance and carcass yield on broilers.

RESUMO -Foram utilizadas 960 codornas para corte, distribuídas num delineamento inteiramente casualizado com esquema fatorial de 2 sexos x 4 níveis de proteína bruta (PB), com 4 repetições de 30 aves cada, para avaliar o desempenho produtivo de 1 a 49 dias de idade, com rações contendo 20%, 22%, 24% e 26% de PB. No período de 1 a 21 dias não houve efeito de nível protéico (p>0,05) sobre nenhuma das características estudadas; as fêmeas foram mais pesadas ao nascer e aos 21 dias e tiveram maior ganho de peso. Nos períodos de 21 a 49 dias e 1 a 49 dias as fêmeas apresentaram consumo médio superior e conversão alimentar inferior aos machos. A mortalidade de machos foi superior (p<0,05) à de fêmeas no período de 21 a 49 dias. Houve interação (p<0,01) para peso médio aos 49 dias, sendo as fêmeas alimentadas com a ração de 24% PB mais pesadas do que as alimentadas com 26% PB, embora não tenha havido efeito de nível protéico sobre o peso dos machos. Houve interação (p<0,01) para ganho de peso médio de 1 a 49 dias, obtendose maior ganho para fêmeas alimentadas com 24% PB do que para as alimentadas com 26% PB; porém o ganho de peso dos machos não foi afetado pelo nível protéico.Palavras chave: Codornas de corte, desempenho, proteína bruta, efeito de sexo.ABSTRACT -In order to evaluate the productive performance of meat quails under diets containing 4 levels of crude proteín (20%, 22%, 24% and 26%) a total of 960 birds were distributed in a completely randomized delineation on a factorial scheme of 2 sexes with 4 replicates of 30 birds each. From 1 to 21 days of age, there was no evidence (p > 0,05) of effect of the protein levels on neither one of the analyzed characteristics. Females displayed higher body weights than males at 1 and 21 days. In the periods from 21 to 49 days and 1 to 49 days, female quails displayed higher mean feed intake and lower feed conversion than males. Mortality of male quails was higher than that of female ones from 21 up to 49 days. An interaction (p < 0.010) has been observed in regard to the mean body weight at 49 day as female that birds fed diets with 24% crude protein showed to be heavier than those fed diets with 26% crude protein. However, there was effect (p < 0.05) of protein level on the weight of male birds. Key-words:Meat quail, growth performance, protein level, sex effect. IntroduçãoA codorna é excelente alternativa para a alimentação humana, pois pode ser utilizada tanto para a produção de ovos como para a de carne. É importante a determinação das suas corretas exigências nutricionais, pois são aves que apresentam um crescimento muito rápido. Mesmo as codornas japonesas tradicionais, utilizadas para postura, que apresentam, ao nascer, peso entre 7,5 a 9,0 g, dobram o seu peso em apenas quatro dias, triplicam-no aos oito e decuplicam-no aos 28, enquanto que os frangos de corte, por exemplo, só dobram o peso ao nascer em torno dos oito ou nove dias (MURAKAMI e ARIKI, 1998). Para as codornas de corte esta velocidade de crescimento é ainda maior, pois,