Soybean extracts can improve plant development

ABSTRACT: Microbial biodiversity of an environment can contribute to plant growth and increase crop yield. Plant extracts from soybean (Glycine max (L.) Merrill) were investigated on soybean plants grown after inoculation with these extracts. Soil samples were collected from two important Brazilian soybean-growing regions to produce the extracts used in the experiments. The extracts were produced with material collected from aboveground biomass and rhizosphere of soybean plants cultivated in a controlled greenhouse (phase 1). The extracts produced in phase 1 were applied in a sequential experiment (phase 2). Phase 2 was conducted to examine the plant microbiome after the microbial alteration process in the greenhouse through seed inoculation with the extracts produced previously. Samples of aboveground biomass were collected to determine root dry matter and crop yield. Bacterial 16S rRNA sequences were processed to determine the final microbial content of soybean. The inoculated treatments had lower species diversity; however, the phyla Firmicutes and Bacteroidetes were more abundant in the treatments than in the non-inoculated treatment. The soybean plant stem in the inoculated treatment also had a positive response to enrichment of the bacterial classes Betaproteobacteria, Bacilli and Flavobacteria. Inoculation affected the microbial composition of soybean plants. The alteration of microbiome changes revealed differences for crop yield between the inoculated and non-inoculated treatments, with up to 93.5 % higher crop yields per plant according to the extract applied.

Requirement of digestible methionine + cystine for growing Japanese quail and its subsequent effects on laying phase

The objective of this study was to estimate the nutritional requirement of digestible methionine + cystine for Japanese quail during the growth phase and its residual effect on the laying phase. One experiment was conducted, including three phases: starter, from 1 to 14 days of age; grower, from 15 to 42 days of age; and laying, from 43 to 168 days of age. The experimental design was entirely randomized with five treatments (0.52, 0.64, 0.76, 0.88, and 1.00% of digestible methionine + cystine) and five replicates. In starter phase, 48 quail/experimental unit (box) were used; in grower phase, 31 quail/experimental unit (box) were used, which were reared until 14 days old, receiving conventional feed and, in laying phase, 12 quail/experimental unit were selected from grower phase to evaluate the residual effect. To evaluate animal performance, feed intake (g/bird), body weight (g), weight gain (g), feed conversion (g/g), and viability (%) were analyzed. At 14 and 42 days of age, the relative weight (%) of liver, spleen, and cloacal pouch organs, the birds' warping (%) and body chemical composition (%) were evaluated. During laying, performance and egg quality were evaluated. In the starter and grower stages, quadratic effects were observed for all performance variables. Laying performance results confirmed the estimates obtained in the grower phase; however, there was no effect on egg quality. Considering the best feed conversion, the nutritional recommendation of digestible methionine + cystine for Japanese quail in the starter phase is 0.85% and in the grower phase, it is 0.77%, corresponding to daily intake of 50.43 and 158.5 mg of digestible methionine + cystine/day, respectively.

Effect of emulsifier addition on metabolizable energy reduction in broiler diets / Adição de emulsificante nas rações de frangos de corte com redução dos níveis de energia metabolizável

This study aimed to evaluate the effect of including soy lecithin emulsifier (SL) in broiler diets with reduced metabolizable energy levels and to correlate it with nutrient metabolizability coefficients, as well as to determine apparent metabolizable energy (AME). Two metabolic trials were conducted in a completely randomized design with a 3x2 factorial arrangement (diet with three levels of metabolizable energy, with or without the inclusion of emulsifier), totaling six treatments. In the starter phase, chicks received diets with 2,950, 3,050, and 3,150 kcal/kg of metabolizable energy, with six replications of 10 birds each, totaling 360 birds. In the grower phase, the energy levels of 3,100, 3,150, and 3,200 kcal/kg of feed were tested in 210 birds were used in seven replications of five chicks each. An interaction effect was observed in the starter phase, with the nitrogen metabolizability coefficient increasing when the emulsifier was added to diets with reduced energy. Additionally, emulsifier inclusion increased nitrogen-corrected AME (AMEn). An interaction effect was also present in the grower phase, with AME and AMEn increasing when the emulsifier was added to diets with lower energy levels. In summary, emulsifier inclusion in broiler diets can reduce metabolizable energy while improving AMEn in both the starter and grower phases, as well as AME in growing broilers.

Objetivou-se avaliar a adição do emulsificante, lecitina de soja, nas rações de frangos com redução dos níveis de energia metabolizável e correlacioná-las com os coeficientes de metabolizabilidade de nutrientes, além da determinação da energia metabolizável aparente (EMA). Realizou-se dois ensaios metabólicos em delineamento inteiramente casualizados, esquema fatorial 3x2 (ração com três níveis de energia metabolizável, com ou sem a inclusão do emulsificante na dieta), totalizando seis tratamentos. Na fase inicial, os pintos receberam dieta com 2.950, 3.050 e 3.150 kcal/kg de energia metabolizável, com seis repetições com 10 aves, totalizando 360 aves. Na fase de crescimento foram utilizadas 210 aves, sendo sete repetições com cinco frangos e os níveis de energia testados foram: 3.100, 3.150 e 3.200 kcal/kg de ração. Na fase inicial, observou-se efeito de interação, apresentando aumento do coeficiente de metabolizabilidade do nitrogênio (CMN) ao adicionar o emulsificante em dietas com energia reduzida e também, efeito do emulsificante no aumento da energia metabolizável aparente corrigida pelo balanço do nitrogênio (EMAn). Na fase de crescimento, observou-se efeito de interação, apresentando aumento da EMA e EMAn ao adicionar o emulsificante em dietas com menores níveis de energia. Conclui-se que a inclusão do emulsificante é indicada para frangos de corte, pois permite reduzir a energia metabolizável da dieta, melhorando a EMAn nas fases inicial e de crescimento, bem como a da EMA com frangos em crescimento.

Soybean extracts can improve plant development

Microbial biodiversity of an environment can contribute to plant growth and increase crop yield. Plant extracts from soybean (Glycine max (L.) Merrill) were investigated on soybean plants grown after inoculation with these extracts. Soil samples were collected from two important Brazilian soybean-growing regions to produce the extracts used in the experiments. The extracts were produced with material collected from aboveground biomass and rhizosphere of soybean plants cultivated in a controlled greenhouse (phase 1). The extracts produced in phase 1 were applied in a sequential experiment (phase 2). Phase 2 was conducted to examine the plant microbiome after the microbial alteration process in the greenhouse through seed inoculation with the extracts produced previously. Samples of aboveground biomass were collected to determine root dry matter and crop yield. Bacterial 16S rRNA sequences were processed to determine the final microbial content of soybean. The inoculated treatments had lower species diversity; however, the phyla Firmicutes and Bacteroidetes were more abundant in the treatments than in the non-inoculated treatment. The soybean plant stem in the inoculated treatment also had a positive response to enrichment of the bacterial classes Betaproteobacteria, Bacilli and Flavobacteria. Inoculation affected the microbial composition of soybean plants. The alteration of microbiome changes revealed differences for crop yield between the inoculated and non-inoculated treatments, with up to 93.5 % higher crop yields per plant according to the extract applied.

Effect of natural food consumption on the first phase of pirarucu grow-out in ponds and cages / Efeito do consumo de alimento natural sobre a recria do pirarucu em viveiros e tanques-rede

Pirarucu, Arapaima gigas is a fish species of great social and economic importance in the Amazon region, where they are often farmed in earthen ponds. Intensive cage aquaculture has been growing in Brazil, which could be an alternative means to farm pirarucu, reducing costs and increasing productivity. We evaluated the contribution of natural food organisms in semi-intensive (ponds) and intensive (cages) production systems, and their effect on pirarucu growth and economic performance during the first phase of grow-out. Four ponds (300 m2) and four cages (4.0 m³) were stocked, respectively, with 120 (0.4 fish m-²) and 160 (40 fish m-³) juvenile pirarucu (28.03 ± 6.34 g, 11.75 ± 0.80 cm). The study was conducted for 105 days and fish were fed with commercial feed. Fish growth and plankton intake were evaluated every two weeks. Survival rate, standard length, weight gain and final weight were higher in fish reared in earthen ponds than in cages. Feed conversion of fish kept in ponds was lower (0.96 ± 0.06) than in cages (1.20 ± 0.11). The consumption of natural food organisms was observed, despite artificial feed being fed in both systems. The relative abundance of zooplankton and insects in stomachs was directly proportional to fish weight gain in ponds, and inversely proportional in cages. Higher economic efficiency rate and lower average production cost were calculated for earthen ponds. Our results indicate that the cost-benefit of the first phase grow-out of A. gigas is better in earthen ponds.(AU)

O pirarucu, Arapaima gigas é um peixe de grande importância econômica e social na Amazônia, onde é comumente produzido em viveiros. A produção de peixes em tanques-rede tem crescido no Brasil, e este sistema poderia ser uma alternativa para a produção do pirarucu, reduzindo custos e melhorando os parâmetros produtivos. Nós avaliamos a contribuição do alimento natural na produção em sistema semi-intensivo (viveiros) e intensivo (tanques-rede) e seus efeitos sobre os aspectos produtivos e econômicos do pirarucu na fase de recria. Quatro viveiros (300 m2) e quatro tanques-rede (4,0 m3) foram estocados, respectivamente, com 120 (0,4 peixes m-2) e 160 (40 peixes m-3) juvenis de pirarucu (28,03 ± 6,34 g e 11,75 ± 0,80 cm). O estudo foi conduzido por 105 dias e os peixes foram alimentados com ração comercial extrusada. Crescimento e ingestão de plâncton pelos peixes foram avaliados quinzenalmente. Sobrevivência, comprimento padrão, ganho de peso e peso final foram maiores nos peixes cultivados em viveiros. A conversão alimentar nos viveiros (0,96 ± 0,06) foi menor que nos tanques-rede (1,20 ± 0,11). Mesmo sendo ofertada ração, os pirarucus consumiram alimento natural nos dois sistemas de produção. A abundância relativa de zooplâncton e insetos nos estômagos foi diretamente proporcional ao ganho de peso nos viveiros, e inversamente proporcional nos tanques-rede. Um índice de eficiência econômica mais alto e custo médio de produção mais baixo foram calculados para os viveiros escavados. Nossos resultados indicam que o custo-benefício do cultivo de A. gigas durante a fase de recria é melhor em viveiros.(AU)

Morphometric measurements and carcass characteristics of Black Australorp, Naked Neck, and Rhode Island Red crossbreds under alternative production systems

Abstract The present trial explained the effect of alternative production systems on growth, morphometric and carcass traits of four different chicken genotypes. The second generation of two genotypes RNN (Rhode Island Red × Naked Neck) and BNN (Black Australorp × Naked Neck) obtained by two self-crosses (RNN × RNN = RR and BNN × BNN = BB) and two reciprocal crosses (RNN × BNN = RB and BNN × RNN = BR) were evaluated in three alternative production systems (conventional cages, enriched cages, and aviary). At the 6th week of age after sexing, a total of 600 birds, comprising 150 from each crossbred with a total of 300 pullets and 300 cockerels were divided into conventional cages, enriched cages, and aviary systems having 200 birds in each.Birds were organized into 3×4 factorial arrangements under Completely Randomized Design (3 production systems × 4 genotypes × 2 sexes × 25 birds = 600 birds). Regarding genotypes, RB and BR males showed higher (p 0.01) carcass yield, drumstick weight, breast weight, and thigh weight than BB and RR genotypes. Females of BR genotype showed higher (p 0.01) breast weight, thigh weight and drumstick weight. As far as production systems are concerned, higher (p 0.01) liver weight, heart weight, breast weight, intestinal weight, drumstick weight, and thigh weight were observed in the males reared in enriched cages compared with conventional cages and aviary system. Females reared in enriched cages showed higher (p 0.01) heart weight, breast weight, intestinal weight, drumstick weight, and thigh weight when compared with those reared in conventional cages and aviary. It is concluded that chickens (both sexes) of BR and RB genotypes had better morphological measurements and carcass traits than those of RR and BB genotype chickens. Among alternative production systems, chickens reared in enriched cages had better traits than those of reared in conventional cages and aviary during the growing phase.

Resumo O presente estudo explicou o efeito de sistemas alternativos de produção sobre o crescimento, características morfométricas e carcaças de quatro genótipos de frango diferentes. A segunda geração de dois genótipos RNN (Rhode Island Red × Naked Neck) e BNN (Black Australorp × Naked Neck) obtida por duas autocruzes (RNN × RNN = RR e B ANN × BNN = BB) e duas cruzes recíprocas (RNN × BNN = RB e BNN × RNN = BR) foi avaliada em três sistemas de produção alternativos (gaiolas convencionais, gaiolas enriquecidas e aviário). Na 6ª semana de idade após o sexo, um total de 600 aves, compostas por 150 de cada raça cruzada com um total de 300 pullets e 300 galos, foi dividido em gaiolas convencionais, gaiolas enriquecidas e sistemas aviários com 200 aves em cada. As aves foram organizadas em 3×4 arranjos fatoriais sob projeto completamente randomizado (3 sistemas de produção × 4 genótipos × 2 sexos × 25 aves = 600 aves). Em relação aos genótipos, os machos RB e BR apresentaram maior rendimento de carcaça (p 0,01), peso da baqueta, peso mamário e peso da coxa do que os genótipos BB e RR. As fêmeas do genótipo BR apresentaram maior (p 0,01) peso mamário, peso da coxa e peso da baqueta. No que diz respeito aos sistemas de produção, maior (p 0,01) peso hepático, peso cardíaco, peso mamário, peso intestinal, peso da baqueta e peso da coxa foram observados nos machos criados em gaiolas enriquecidas em comparação com gaiolas convencionais e sistema aviário. As fêmeas criadas em gaiolas enriquecidas apresentaram maior (p 0,01) peso cardíaco, peso mamário, peso intestinal, peso da baqueta e peso da coxa quando comparadas com as criadas em gaiolas convencionais e aviárias. Conclui-se que as galinhas (ambos os sexos) dos genótipos BR e RB apresentaram melhores medidas morfológicas e traços de carcaça do que os de frangos genótipos RR e BB. Entre os sistemas de produção alternativos, as galinhas criadas em gaiolas enriquecidas tinham características melhores do que as criadas em gaiolas convencionais e aviárias durante a fase de cultivo.

Inclusion of Stored Wheat in the Feed of Broilers Influences Intake, Growth Performance, Nutrient Digestibility, and Digesta Viscosity from 1-21 Days of Age

The objective of the current study was to examine the effect of replacing maize with new or stored wheat on the nutrient intake, digestibility, digesta viscosity, and growth performance of growing broilers from 1-21 days of age. For this purpose, 560 one-day-old male broiler chicks were randomly divided into seven experimental treatments, each with 8 replicates of 10 birds. The control diet was a corn soybean-based diet, while six other experimental treatments replaced the corn of the control diet with either 50% or 100% of new, 1.5 year, and 2.5-year-old wheat. The results showed that the replacement of corn with new wheat at 50% and 100% in the diet of broilers significantly reduced feed intake and body weight gain, and increased FCR (p<0.05) at week 3. Similarly, in the overall period of the starter phase (1-21 days), replacement of corn with new wheat at 50% and 100% in the diet of broilers significantly reduced feed intake, nutrient digestibility, and body weight gain, and increased digesta viscosity and FCR (p<0.05). Based on the findings of the current study, it is concluded that stored wheat successfully replaces corn and new wheat in the diet of broilers. Furthermore, stored wheat has a positive impact on feed intake, performance parameter, digesta viscosity, and nutrient digestibility as compared to new wheat.(AU)

Morphometric measurements and carcass characteristics of Black Australorp, Naked Neck, and Rhode Island Red crossbreds under alternative production systems / Medições morfométricas e características de carcaça de Black Australorp, Naked Neck e Rhode Island Red crossbreds sob sistemas de produção alternativos

Abstract The present trial explained the effect of alternative production systems on growth, morphometric and carcass traits of four different chicken genotypes. The second generation of two genotypes RNN (Rhode Island Red × Naked Neck) and BNN (Black Australorp × Naked Neck) obtained by two self-crosses (RNN × RNN = RR and BNN × BNN = BB) and two reciprocal crosses (RNN × BNN = RB and BNN × RNN = BR) were evaluated in three alternative production systems (conventional cages, enriched cages, and aviary). At the 6th week of age after sexing, a total of 600 birds, comprising 150 from each crossbred with a total of 300 pullets and 300 cockerels were divided into conventional cages, enriched cages, and aviary systems having 200 birds in each.Birds were organized into 3×4 factorial arrangements under Completely Randomized Design (3 production systems × 4 genotypes × 2 sexes × 25 birds = 600 birds). Regarding genotypes, RB and BR males showed higher (p < 0.01) carcass yield, drumstick weight, breast weight, and thigh weight than BB and RR genotypes. Females of BR genotype showed higher (p < 0.01) breast weight, thigh weight and drumstick weight. As far as production systems are concerned, higher (p < 0.01) liver weight, heart weight, breast weight, intestinal weight, drumstick weight, and thigh weight were observed in the males reared in enriched cages compared with conventional cages and aviary system. Females reared in enriched cages showed higher (p < 0.01) heart weight, breast weight, intestinal weight, drumstick weight, and thigh weight when compared with those reared in conventional cages and aviary. It is concluded that chickens (both sexes) of BR and RB genotypes had better morphological measurements and carcass traits than those of RR and BB genotype chickens. Among alternative production systems, chickens reared in enriched cages had better traits than those of reared in conventional cages and aviary during the growing phase.

Resumo O presente estudo explicou o efeito de sistemas alternativos de produção sobre o crescimento, características morfométricas e carcaças de quatro genótipos de frango diferentes. A segunda geração de dois genótipos RNN (Rhode Island Red × Naked Neck) e BNN (Black Australorp × Naked Neck) obtida por duas autocruzes (RNN × RNN = RR e B ANN × BNN = BB) e duas cruzes recíprocas (RNN × BNN = RB e BNN × RNN = BR) foi avaliada em três sistemas de produção alternativos (gaiolas convencionais, gaiolas enriquecidas e aviário). Na 6ª semana de idade após o sexo, um total de 600 aves, compostas por 150 de cada raça cruzada com um total de 300 pullets e 300 galos, foi dividido em gaiolas convencionais, gaiolas enriquecidas e sistemas aviários com 200 aves em cada. As aves foram organizadas em 3×4 arranjos fatoriais sob projeto completamente randomizado (3 sistemas de produção × 4 genótipos × 2 sexos × 25 aves = 600 aves). Em relação aos genótipos, os machos RB e BR apresentaram maior rendimento de carcaça (p < 0,01), peso da baqueta, peso mamário e peso da coxa do que os genótipos BB e RR. As fêmeas do genótipo BR apresentaram maior (p < 0,01) peso mamário, peso da coxa e peso da baqueta. No que diz respeito aos sistemas de produção, maior (p < 0,01) peso hepático, peso cardíaco, peso mamário, peso intestinal, peso da baqueta e peso da coxa foram observados nos machos criados em gaiolas enriquecidas em comparação com gaiolas convencionais e sistema aviário. As fêmeas criadas em gaiolas enriquecidas apresentaram maior (p < 0,01) peso cardíaco, peso mamário, peso intestinal, peso da baqueta e peso da coxa quando comparadas com as criadas em gaiolas convencionais e aviárias. Conclui-se que as galinhas (ambos os sexos) dos genótipos BR e RB apresentaram melhores medidas morfológicas e traços de carcaça do que os de frangos genótipos RR e BB. Entre os sistemas de produção alternativos, as galinhas criadas em gaiolas enriquecidas tinham características melhores do que as criadas em gaiolas convencionais e aviárias durante a fase de cultivo.

Morphometric measurements and carcass characteristics of Black Australorp, Naked Neck, and Rhode Island Red crossbreds under alternative production systems / Medições morfométricas e características de carcaça de Black Australorp, Naked Neck e Rhode Island Red crossbreds sob sistemas de produção alternativos

The present trial explained the effect of alternative production systems on growth, morphometric and carcass traits of four different chicken genotypes. The second generation of two genotypes RNN (Rhode Island Red × Naked Neck) and BNN (Black Australorp × Naked Neck) obtained by two self-crosses (RNN × RNN = RR and BNN × BNN = BB) and two reciprocal crosses (RNN × BNN = RB and BNN × RNN = BR) were evaluated in three alternative production systems (conventional cages, enriched cages, and aviary). At the 6th week of age after sexing, a total of 600 birds, comprising 150 from each crossbred with a total of 300 pullets and 300 cockerels were divided into conventional cages, enriched cages, and aviary systems having 200 birds in each.Birds were organized into 3×4 factorial arrangements under Completely Randomized Design (3 production systems × 4 genotypes × 2 sexes × 25 birds = 600 birds). Regarding genotypes, RB and BR males showed higher (p < 0.01) carcass yield, drumstick weight, breast weight, and thigh weight than BB and RR genotypes. Females of BR genotype showed higher (p < 0.01) breast weight, thigh weight and drumstick weight. As far as production systems are concerned, higher (p < 0.01) liver weight, heart weight, breast weight, intestinal weight, drumstick weight, and thigh weight were observed in the males reared in enriched cages compared with conventional cages and aviary system. Females reared in enriched cages showed higher (p < 0.01) heart weight, breast weight, intestinal weight, drumstick weight, and thigh weight when compared with those reared in conventional cages and aviary. It is concluded that chickens (both sexes) of BR and RB genotypes had better morphological measurements and carcass traits than those of RR and BB genotype chickens. Among alternative production systems, chickens reared in enriched cages had better traits than those of reared in conventional cages and aviary during the growing phase.

O presente estudo explicou o efeito de sistemas alternativos de produção sobre o crescimento, características morfométricas e carcaças de quatro genótipos de frango diferentes. A segunda geração de dois genótipos RNN (Rhode Island Red × Naked Neck) e BNN (Black Australorp × Naked Neck) obtida por duas autocruzes (RNN × RNN = RR e B ANN × BNN = BB) e duas cruzes recíprocas (RNN × BNN = RB e BNN × RNN = BR) foi avaliada em três sistemas de produção alternativos (gaiolas convencionais, gaiolas enriquecidas e aviário). Na 6ª semana de idade após o sexo, um total de 600 aves, compostas por 150 de cada raça cruzada com um total de 300 pullets e 300 galos, foi dividido em gaiolas convencionais, gaiolas enriquecidas e sistemas aviários com 200 aves em cada. As aves foram organizadas em 3×4 arranjos fatoriais sob projeto completamente randomizado (3 sistemas de produção × 4 genótipos × 2 sexos × 25 aves = 600 aves). Em relação aos genótipos, os machos RB e BR apresentaram maior rendimento de carcaça (p < 0,01), peso da baqueta, peso mamário e peso da coxa do que os genótipos BB e RR. As fêmeas do genótipo BR apresentaram maior (p < 0,01) peso mamário, peso da coxa e peso da baqueta. No que diz respeito aos sistemas de produção, maior (p < 0,01) peso hepático, peso cardíaco, peso mamário, peso intestinal, peso da baqueta e peso da coxa foram observados nos machos criados em gaiolas enriquecidas em comparação com gaiolas convencionais e sistema aviário. As fêmeas criadas em gaiolas enriquecidas apresentaram maior (p < 0,01) peso cardíaco, peso mamário, peso intestinal, peso da baqueta e peso da coxa quando comparadas com as criadas em gaiolas convencionais e aviárias. Conclui-se que as galinhas (ambos os sexos) dos genótipos BR e RB apresentaram melhores medidas morfológicas e traços de carcaça do que os de frangos genótipos RR e BB. Entre os sistemas de produção alternativos, [...].

Morphometric measurements and carcass characteristics of Black Australorp, Naked Neck, and Rhode Island Red crossbreds under alternative production systems / Medições morfométricas e características de carcaça de Black Australorp, Naked Neck e Rhode Island Red crossbreds sob sistemas de produção alternativos

The present trial explained the effect of alternative production systems on growth, morphometric and carcass traits of four different chicken genotypes. The second generation of two genotypes RNN (Rhode Island Red × Naked Neck) and BNN (Black Australorp × Naked Neck) obtained by two self-crosses (RNN × RNN = RR and BNN × BNN = BB) and two reciprocal crosses (RNN × BNN = RB and BNN × RNN = BR) were evaluated in three alternative production systems (conventional cages, enriched cages, and aviary). At the 6th week of age after sexing, a total of 600 birds, comprising 150 from each crossbred with a total of 300 pullets and 300 cockerels were divided into conventional cages, enriched cages, and aviary systems having 200 birds in each.Birds were organized into 3×4 factorial arrangements under Completely Randomized Design (3 production systems × 4 genotypes × 2 sexes × 25 birds = 600 birds). Regarding genotypes, RB and BR males showed higher (p < 0.01) carcass yield, drumstick weight, breast weight, and thigh weight than BB and RR genotypes. Females of BR genotype showed higher (p < 0.01) breast weight, thigh weight and drumstick weight. As far as production systems are concerned, higher (p < 0.01) liver weight, heart weight, breast weight, intestinal weight, drumstick weight, and thigh weight were observed in the males reared in enriched cages compared with conventional cages and aviary system. Females reared in enriched cages showed higher (p < 0.01) heart weight, breast weight, intestinal weight, drumstick weight, and thigh weight when compared with those reared in conventional cages and aviary. It is concluded that chickens (both sexes) of BR and RB genotypes had better morphological measurements and carcass traits than those of RR and BB genotype chickens. Among alternative production systems, chickens reared in enriched cages had better traits than those of reared in conventional cages and aviary during the growing phase.(AU)

O presente estudo explicou o efeito de sistemas alternativos de produção sobre o crescimento, características morfométricas e carcaças de quatro genótipos de frango diferentes. A segunda geração de dois genótipos RNN (Rhode Island Red × Naked Neck) e BNN (Black Australorp × Naked Neck) obtida por duas autocruzes (RNN × RNN = RR e B ANN × BNN = BB) e duas cruzes recíprocas (RNN × BNN = RB e BNN × RNN = BR) foi avaliada em três sistemas de produção alternativos (gaiolas convencionais, gaiolas enriquecidas e aviário). Na 6ª semana de idade após o sexo, um total de 600 aves, compostas por 150 de cada raça cruzada com um total de 300 pullets e 300 galos, foi dividido em gaiolas convencionais, gaiolas enriquecidas e sistemas aviários com 200 aves em cada. As aves foram organizadas em 3×4 arranjos fatoriais sob projeto completamente randomizado (3 sistemas de produção × 4 genótipos × 2 sexos × 25 aves = 600 aves). Em relação aos genótipos, os machos RB e BR apresentaram maior rendimento de carcaça (p < 0,01), peso da baqueta, peso mamário e peso da coxa do que os genótipos BB e RR. As fêmeas do genótipo BR apresentaram maior (p < 0,01) peso mamário, peso da coxa e peso da baqueta. No que diz respeito aos sistemas de produção, maior (p < 0,01) peso hepático, peso cardíaco, peso mamário, peso intestinal, peso da baqueta e peso da coxa foram observados nos machos criados em gaiolas enriquecidas em comparação com gaiolas convencionais e sistema aviário. As fêmeas criadas em gaiolas enriquecidas apresentaram maior (p < 0,01) peso cardíaco, peso mamário, peso intestinal, peso da baqueta e peso da coxa quando comparadas com as criadas em gaiolas convencionais e aviárias. Conclui-se que as galinhas (ambos os sexos) dos genótipos BR e RB apresentaram melhores medidas morfológicas e traços de carcaça do que os de frangos genótipos RR e BB. Entre os sistemas de produção alternativos, [...].(AU)

Dietary net energy levels for growing barrows from 30 to 70 kg / Níveis de energia líquida para suínos machos castrados dos 30 aos 70 kg

This study evaluated the effect of dietary net energy (NE) levels on growth performance and carcass characteristics of barrows from 30 to 70 kg of body weight (BW). Sixty barrows with initial body weight (IBW) of 31.94 ± 3.54 kg and final body weight (FBW) of 71.98 ± 5.99 kg were allotted to one of five dietary NE levels (2.40, 2.45, 2.50, 2.55, and 2.60 Mcal kg-¹), using a completely randomized block design with six replicates and two barrows per replicate. The experimental period was divided into phase I: 30 to 50 kg and phase II: 50 to 70 kg. The variables analyzed were average daily feed intake (ADFI), net energy intake (NEI), digestible lysine intake (LysI), average daily gain (ADG), feed conversion (FC), FBW, digestible lysine conversion:gain (LysI:G), Cost:Gain (C:G), loin eye area (LEA), muscle depth (MD), first backfat layer (BF1), second backfat layer (BF2), total backfat (BFt), lean meat percentage, and carcass bonus index (BI). In phase I, there was a linear increase (P < 0.05) in FBW, ADG, NEI, and LysI with increasing NE levels in the diet. In phase II, increasing dietary NE levels also increased (P < 0.05) FBW, ADG, NEI, LysI, and FC linearly. Overall, there was a linear increase (P < 0.05) in ADG, NEI, LysI, and FC with increasing NE levels in the diet. The other performance variables were not affected (P > 0.05) by the NE levels. There was an increase (P < 0.05) in BF2 with increasing NE levels, but the other carcass characteristics were not altered (P > 0.05). We recommended 2.60 Mcal of NE kg-¹ in the diet for growing barrows from 30 to 70 kg.

Realizou-se este estudo com o objetivo de avaliar níveis de energia líquida (EL), mantendo a relação caloria: nutriente, no desempenho e características de carcaça de suínos dos 30 aos 70 kg. Foram utilizados 60 suínos machos castrados, com pesos iniciais de 31,94 ± 3,54 kg e finais de 71,98 ± 5,99 kg. Os animais foram distribuídos em delineamento experimental de blocos casualizados, em cinco níveis de EL (2,40; 2,45; 2,50; 2,55; 2,60 Mcal de EL kg-¹ de dieta), com seis repetições e dois animais por unidade experimental. O período experimental foi dividido em fase I: 30 aos 50 kg e fase II: 50 aos 70 kg. As variáveis analisadas foram os consumos de ração diária (CRD), energia líquida (CEL) e lisina digestível (CLdig), ganho de peso diário (GPD), conversão alimentar (CA), peso final (PF), conversão de lisina digestível: ganho (CLdig:G), custo: ganho (C:G), área de olho de lombo (AOL), profundidade de músculo (PM), espessura de toucinho da primeira camada (ET1), espessura de toucinho da segunda camada (ET2), espessura de toucinho total (ETt), percentual de carne magra (CM) e o índice de bonificação de carcaça (IB). Dos 30 aos 50 kg, verificou-se aumento linear (P < 0,05) do PF, GPD e dos CEL e CLdig com o aumento dos níveis de EL na dieta. Dos 50 aos 70 kg, o aumento dos níveis de EL na dieta promoveu melhora linear (P < 0,05) do PF, GPD, CEL, CLdig e da CA dos suínos. No período total, verificou-se aumento linear (P < 0,05) do GPD, CEL, CLdig e melhora linear (P < 0,05) da CA de acordo com o aumento do nível de EL na dieta. As demais variáveis de desempenho não foram afetadas (P > 0,05) pelos níveis de EL. Verificou-se aumento (P < 0,05) da ET2 de acordo com o aumento do nível de EL, porém sem alterar (P > 0,05) as demais características de carcaça. Recomenda-se o nível 2,60 Mcal de EL kg-¹ de dieta para suínos machos castrados dos 30 aos 70 kg.

Performance, carcass characteristics, and health parameters of growing and finishing pigs fed with diets supplemented with isoquinoline alkaloids and essential oils / Desempenho zootécnico, características de carcaça e parâmetros de saúde de suínos em crescimento e terminação submetidos a dietas suplementadas com alcaloides isoquinolínicos e óleos essenciais

The goal of this study was to evaluate, in a commercial herd, the use of isoquinoline alkaloids and carvacrol versus a preventive antibiotic program, such as feed additives, on the performance, carcass traits, and health status of pigs in the growing and finishing phase. There were 576 PIC immunocastrated males and females, at 70 days of age and 28.429 ± 2.302 kg of initial weight used. The experimental design was a 4 × 2 factorial randomized block, with four preventive programs, two sexes, and six repetitions per treatment (the pen with 12 animals of the same sex was the replicate). The treatments were T1 (positive control program with antibiotic shocks at preventive level), T2 (negative control with the absence of antibiotics as a growth promoter or as preventive), T3 (isoquinoline alkaloids at 100 to 150 g ton-1), T4 (isoquinoline alkaloids at 90 g ton-1 + carvacrol essential oil at 1 kg ton-1). T1 and T3 presented higher daily feed intakes, followed by T2, and T4 showed the worst feed consumption (P < 0.05). T1 showed higher daily weight gain compared to T4 (P < 0.05), without differences between T2 and T3. T2 showed better feed conversion than T1 and T3, but it was similar to T4. There were no effects of the treatments on the carcass traits. Intestinal crypt hyperplasia and crypt abscesses (lesions caused by Lawsonia intracellularis) were significantly higher for T2 and T3 compared to T1, which was similar to T4. T2 presented the highest carcass condemnation at slaughter (7%), differing (P < 0.05) from T1, T3, and T4 (1, 2, and 3%, respectively). Isoquinoline alkaloids are an alternative for antibiotic-free diets for pigs in the growing and finishing phase, preserving the performance and carcass indices and minimizing sanitary carcass condemnations at the slaughterhouse.(AU)

O objetivo deste trabalho foi avaliar, em um rebanho comercial, o uso de alcalóides isoquinolínicos e do carvacrol frente a um programa preventivo com antibióticos, como aditivos alimentares, sobre o desempenho zootécnico, características de carcaça e o status de saúde de suínos em fase de recria e terminação. Foram utilizados 576 suínos PIC, machos imunocastrados e fêmeas, com 70 dias de idade e 28.429 ± 2.302 kg de peso médio inicial. O delineamento experimental foi em blocos casualizados, modelo fatorial 4 x 2, com quatro programas preventivos e dois sexos e 6 repetições por tratamento (baia com 12 animais do mesmo sexo representou a unidade experimental). Os tratamentos foram: T1 - Controle Positivo (programa com choque antibiótico em nível preventivo), T2 - Controle Negativo (ausência de aditivos promotores de crescimento ou preventivos), T3 - Alcalóides isoquinolínicos (100 a 150 g ton-1), T4 - Alcalóides isoquinolínicos (90 g ton-1) + Óleo essencial - carvacrol (1 kg ton-1). T1 e T3 apresentaram maior consumo diário de ração, seguidos de T2, sendo que T4 apresentou o pior consumo (P < 0,05). O ganho de peso diário foi maior para T1 em relação a T4 (P < 0,05), não sendo verificada diferença entre T1 versus T2 e T3. T2 apresentou melhor conversão alimentar que T1 e T3, não diferindo de T4. Não houve efeito dos tratamentos para as características da carcaça. A hiperplasia e o abscesso das criptas intestinais (lesões causadas pela Lawsonia Intracellularis) foram significativamente superiores para T2 e T3 comparado com T1, que foi semelhante a T4. T2 apresentou maiores condenações de carcaça ao abate (7%), diferindo (P < 0,05) de T1, T3 e T4, respectivamente, 1, 2 e 3%. Os alcaloides isoquinolínicos são uma alternativa para dietas isentas de antibióticos para suínos em fase de crescimento e terminação, preservando o desempenho e os índices de carcaça e minimizando as condenações sanitárias de carcaças no frigorífico.(AU)

Stress and fear responses of slow-growing broiler chickens to light stimulation initiated at different phases of embryonic development

Photo-incubation can influence the fear and stress responses of poultry. However, it is unclear how photostimulation initiated at different phases of development influences the welfare status of slow-growing broiler birds. 500 Sasso eggs were assigned to 4 treatments; some were incubated in the dark throughout incubation (TA), while TB, TC and TD were photo-stimulated (12L:12D) from days 1, 7, and 14 of incubation, respectively, until hatch using a 6,500k LED at 788 clux intensity. Birds were raised in 5 replicates per treatment with 16 birds per replicate using a 6,500k LED (at 28 clux) and a photoperiod of 16L:8D. Fear (emergence, tonic immobility, isolation and inversion tests) and stress response (physical asymmetry) of 10 birds per treatment were examined. At the end of the three-week brooding, all parameters measured were not significantly influenced (P > 0.05) by the onset of photo-incubation. At slaughter age (12 weeks), physical asymmetry was significantly higher (P < 0.05) in TA compared to the other treatments. The frequency of isolation vocalisation was significantly lower (P < 0.05) in TB compared to TA, and latency to rightness during tonic immobility was significantly higher (P < 0.05) in TA compared to the other treatments. Latency to emerge was significantly longer (P < 0.05) in TA compared to TC and TD. The frequency of wing flaps during inversion was significantly higher (P < 0.05) in TA and TD. Conclusively, photo-incubating eggs reduce stress and fear, and initiating photo-incubation during the first phase of incubation is more beneficial.

Agrometeorological models for predicting seedlings development of two native forest species

Models of development are tools that connect the effects of development on the environment, allowing their applications in several studies. Nevertheless, studies are scarce on models of development for native forest species in Brazil. This study aimed to predict the development of two native forest species - Citharexylum myrianthum Cham. and Bixa orellana L. - with two agrometeorological models, being one linear (Phyllochron) and another nonlinear (Wang and Engel, 1998). Both models predict the cumulative leaf number (CLN) on a daily basis, which generates the seedling phase duration (SPD) when integrated to time. Data were used from two years of experiments conducted during 2015 and 2016 growing seasons and 12 sowing dates in Itajubá, Minas Gerais State, Brazil. These species × sowing dates × years experiments provided a rich dataset for calibrating and evaluating both models. Although both models used in the study allowed predicting the dynamics of leaf development, CLN, and SPD in two native forest species, the Wang and Engel model provided a more accurate prediction of CLN and SPD for C. myrianthum species, with an overall root mean square error (RMSE) of 1.82 leaves (CLN) and 5.9 days (SPD). For B. orellana, the Phyllochron model was slightly better, with an overall RMSE of 1.48 leaves (CLN) and seven days (SDP).

Soybean meal particle size for pigs during the nursery phase / Tamanho da partícula do farelo de soja em suínos no período de creche

This study evaluated the effect of soybean meal (SBM) particle size on nutrient digestibility and the growth performance of nursery piglets. Sixty-three piglets (BW = 6.86 kg ± 0.56; 23 d of age) were distributed in a randomized block design (by initial weight and sex) with 3 dietary treatments: diets with 1,017 µm (unground); 585 µm; and 411µm SBM, with 7 replicates of 3 piglets each. All diets were offered ad libitum in mash form, formulated differently according to three growing phases: (1) with 20% of SBM, from 23 to 32 d of age; (2) with 25% of SBM, from 32 to 44 d of age, and (3) with 30% of SBM, from 44 to 63 d of age. For the first 21 d, pigs fed diets with a medium particle size of SBM (585mm) had better average weight gain and feed/gain ratio (P<0.05). The average feed intake, average body weight gain, and feed/gain ratio from 44 to 63 d improved (P<0.05) with increasing SBM particle sizes, and the average live weight for the overall period increased with coarser SBM (P<0.05). There was a marginally improvement (P < 0.1) on digestible energy as particle size of SBM decreased; although, no differences (P > 0.05) in the coefficients of apparent digestibility of dry matter and crude protein for the assessed SBM particle sizes were observed. It was concluded that the grinding of dietary SBM is not required for piglets during the nursery phase.

O objetivo deste estudo foi avaliar o efeito do tamanho da partícula do farelo de soja (FS) sobre o desempenho e digestibilidade de leitões no período de creche. 63 leitões (6,86 kg ± 0,56; 23 dias de idade) foram distribuídos aleatoriamente em um delineamento de blocos casualizados (peso inicial e sexo) entre os tratamentos. As dietas experimentais foram produzidas a partir de diferentes tamanhos médios de partículas do FS moídos ou não: 1,017 µm (sem moer), 585 µm (moído em peneira de 10 mm), e 411µm (moído em peneira de 3 mm), totalizando três tratamentos com sete repetições de três animais cada. Todas as dietas foram fornecidas na forma farelada e ad libitum, sendo divididas em três fases: 1) com 20% de FS, dos 23 a 32 dias de idade; 2) com 25% de FS, dos 32 a 44 dias de idade; e 3) com 30% de FS, dos 44 a 62 dias de idade. Nos primeiros 21 dias de experimento, os animais consumindo a dieta com o tamanho médio (585 µm) das partículas do FS apresentaram melhores resultados para o ganho de peso médio e conversão alimentar. No período seguinte (44 a 63 d), houve (P<0.05) aumento do consumo de ração médio, do ganho do peso médio e melhor conversão alimentar dos leitões conforme o aumento do tamanho da partícula de FS incluída na ração. Consequentemente, ao final do experimento houve melhora linear do peso vivo médio dos animais com o aumento do tamanho do FS consumido. Foi observado melhora marginalmente significativa (P < 0.1) da energia digestível conforme a redução no tamanho do FS, entretanto, não houve diferença (P > 0.05) no coeficiente de digestibilidade aparente da matéria seca e da proteína bruta dos animais entre os diferentes tamanhos do FS. Em conclusão, de acordo com as condições deste estudo, não se faz necessária a moagem do farelo de soja para leitões no período de creche.

Estudo de métodos naturais para redução de doenças fúngicas em sementes nativas da região Amazônica / Study of natural methods for reducing fungal diseases in native seeds in the Amazon region

Existe uma preocupação na produção de alimentos com a segurança sanitária desde o processo de cultivo até a sua expedição aos centros comerciais. Uma das maiores contaminações em sementes por suas características físicas e químicas, é a contaminação fúngica devida à acidez e umidade dos frutos. As doenças fúngicas entre elas, antracnose, vassoura de bruxa e podridão parda são consideradas importante doenças em pós colheita, ocorrendo, principalmente, sob condições de alta umidade relativa do ar e temperaturas elevadas (26ºC a 28ºC). Dentre as sementes da região Amazônica, destacam-se sementes de (cacau- Theobroma cacao L., pupunha- Bactris gasipaes, tucumã da Amazonas-Astrocaryum aculeatum), que apresentam problemas de contaminação fúngica durante o sistema de cultivo. Métodos de biocontroles com ação antimicrobiana: bactérias endofíticas, rizobactérias e fungo Trichoderma ssp, entre outros estão sendo estudados para a redução destas contaminações fúngicas em estudos in vitro e no campo. O objetivo deste trabalho é apresentar uma revisão bibliográfica sobre a utilização de métodos de biocontrole como uma alternativa promissora no manejo de doenças de plantas na fase de pós-colheita, com excelentes resultados em culturas de grande importância econômica. Assim novas alternativas ecologicamente sustentáveis demonstram a possibilidade de os produtos estudados serem utilizados no manejo da antracnose na pós-colheita.(AU)

There is a concern in food production with health security from cultivation process to its dispatch to redistribution centers. One of the biggest contaminations in seeds due to their physical and chemical characteristics, is the fungal contamination due to the acidity and humidity of the fruits. Fungal diseases including anthracnose, bruca's broom and brownrot are considered important diseases in post-harvest, occurring mainly under conditions of high relative humidity and high temperatures (26ºC to 28ºC). Among the seeds of the Amazon region, seeds of de (cacau- Theobroma cacao L., pupunha- Bactris gasipaes, tucumã da Amazonas- Astrocaryum aculeatum ), that present problems fungals contamination during in their growing cultures sistems. Biocontrol methods with antimicrobial action: endophytic bacteria, rhizobacteria and the fungus Trichoderma ssp, among others, are being studied to reduce these fungal contaminations in in vitro and field studies. The objective of this work is to present a bibliographic review on the use of biocontrol methods as an alternative that is promising in the management of plant diseases in the post-harvest phase, with excellent results in crops of great economic importance. Thus, new ecologically sustainable alternatives demonstrate the possibility of the studied products to be used in the management of anthracnose in the post-harvest period.(AU)

Optimization of banana plantlets acclimatization by hydroponic cultivation

ABSTRACT: Acclimatization is the final phase of banana plantlet production by micropropagation. In this phase, the plantlets are grown in a protected environment with high demand for water, fertilizer and labor, until reaching the standard size and quality required for marketing. The aim of this study was to evaluate the possibility of reducing these costs and the duration of the acclimatization phase, using the hydroponic cultivation technique as compared to the conventional system. PrataAnã banana plantlet performance was measured for both systems under both tropical summer and winter conditions, based upon water and nutrient use efficiency and growing time of the plantlets. In both seasons, the plantlets produced hydroponically presented faster growth of both the shoot and root systems. There was a reduction of 12 days to reach the transplantation point, a significant reduction in plantlet production cost (fertilizers + water) and improved efficiency in space use with an expressive increase in the number of plantlets produced per square meter.

Estimation of productive losses caused by withdrawal of antibiotic growth promoter from pig diets Meta-analysis

ABSTRACT: This study was designed to simulate productive and economic losses due to the withdrawal of antibiotic growth promoters (AGP) from pig diets. Articles that compared diets with AGP (AGP+) or without AGP (AGP) for pigs were collected from electronic databases and the performance results were entered in a database. A meta-analysis was performed following the sequence: graphical analysis, correlation, and variance-covariance. The performance results observed in the meta-analysis, feed cost, and AGP costs were used to build equations to estimate the economic effect of withdrawing AGP. The database comprised 81 scientific articles containing 103 experiments totalizing 42,923 pigs. Avilamycin (24.7 %) was the most frequent AGP in the database, followed by Colistin (15.4 %), Tiamulin (11.7 %), Tylosin (8.0 %), Lincomycin (9.4 %), and Bacitracin (5.4 %). Weight gain (p 0.05) increased in AGP+ diets during post-weaning (6.5 %). However, there was no effect of AGP on weight gain of growing-finishing pigs. There was better (p 0.05) feed conversion in pigs fed AGP+ diets in all rearing phases. Weight gain and feed conversion improved (p 0.05) with the addition of Avilamycin, Bacitracin, and Tylosin. AGP withdrawal in the post-weaning phase increased feed costs by US$ 0.86 per animal and in growing-finishing phase the increase was US$ 3.11. Thus, pigs fed AGP+ diets have a better performance than pigs fed AGP- diets and the withdrawal of AGP increases feed costs.

Different densities of common snook reared in marine cages in southern Brazil / Diferentes densidades de robalo flecha criados em tanques rede marinhos no sul do Brasil

Two growth stages of juvenile snook (Centropomus undecimalis) under three different densities were evaluated: 10, 20, and 40 fish m-3, in 2.5-m3 cages with 12-mm mesh. In phase I, snooks of 72.0 g and 21.2 cm were raised for 270 days. In phase II, snooks of 204.6 g and 29.2 cm were raised for 202 days. The average water temperature and salinity were 24.3°C and 34.5, respectively, at Santa Catarina Island, Brazil. The data were evaluated using regression models. Density increase did not influence survival rate, with 51.0% (phase I) and 88.7% (phase II). The density of 20 fish m-3 provided the best results, such as body weight, in the two phases, with 215.7 and 364.7 g, respectively. Water temperature was the main limiting factor for the growth of snook. Therefore, in a subtropical climate, it is recommended to start growing in the spring (> 24°C) and avoid handling fish when the temperature is below 20°C. Regression analysis on the final weight showed that densities of 24 fish m-3 could be indicated for common snook under the conditions of this study.

Foram avaliadas duas fases de crescimento de juvenis de robalo flecha (Centropomus undecimalis) sob três diferentes densidades: 10, 20 e 40 peixes m-3, em tanques rede de 2,5 m3 com malha de 12 mm. Na fase I, robalos de 72,0 g e 21,2 cm foram criados por 270 dias. Na fase II, robalos de 204,6 g e 29,2 cm foram criados por 202 dias. A temperatura e salinidade médias da água foram 24,3°C e 34,5, respectivamente, na Ilha de Santa Catarina, Brasil. Os dados foram avaliados por modelos de regressão. O aumento da densidade não influenciou a taxa de sobrevivência, 51,0% (fase I) e 88,7% (fase II). A densidade de 20 peixes m-3 proporcionou os melhores resultados, como peso corporal, nas duas fases, 215,7 g e 364,7 g, respectivamente. A temperatura da água foi o principal fator limitante para o crescimento do robalo. Portanto, em um clima subtropical, recomenda-se começar a crescer na primavera (> 24°C) e evitar o manuseio de peixes quando a temperatura estiver abaixo de 20°C. A análise de regressão do peso final mostrou que densidades de 24 peixes m-3 podem ser indicadas para robalo nas condições deste estudo.

Different densities of common snook reared in marine cages in southern Brazil / Diferentes densidades de robalo flecha criados em tanques rede marinhos no sul do Brasil

Two growth stages of juvenile snook (Centropomus undecimalis) under three different densities were evaluated: 10, 20, and 40 fish m-3, in 2.5-m3 cages with 12-mm mesh. In phase I, snooks of 72.0 g and 21.2 cm were raised for 270 days. In phase II, snooks of 204.6 g and 29.2 cm were raised for 202 days. The average water temperature and salinity were 24.3°C and 34.5, respectively, at Santa Catarina Island, Brazil. The data were evaluated using regression models. Density increase did not influence survival rate, with 51.0% (phase I) and 88.7% (phase II). The density of 20 fish m-3 provided the best results, such as body weight, in the two phases, with 215.7 and 364.7 g, respectively. Water temperature was the main limiting factor for the growth of snook. Therefore, in a subtropical climate, it is recommended to start growing in the spring (> 24°C) and avoid handling fish when the temperature is below 20°C. Regression analysis on the final weight showed that densities of 24 fish m-3 could be indicated for common snook under the conditions of this study.(AU)

Foram avaliadas duas fases de crescimento de juvenis de robalo flecha (Centropomus undecimalis) sob três diferentes densidades: 10, 20 e 40 peixes m-3, em tanques rede de 2,5 m3 com malha de 12 mm. Na fase I, robalos de 72,0 g e 21,2 cm foram criados por 270 dias. Na fase II, robalos de 204,6 g e 29,2 cm foram criados por 202 dias. A temperatura e salinidade médias da água foram 24,3°C e 34,5, respectivamente, na Ilha de Santa Catarina, Brasil. Os dados foram avaliados por modelos de regressão. O aumento da densidade não influenciou a taxa de sobrevivência, 51,0% (fase I) e 88,7% (fase II). A densidade de 20 peixes m-3 proporcionou os melhores resultados, como peso corporal, nas duas fases, 215,7 g e 364,7 g, respectivamente. A temperatura da água foi o principal fator limitante para o crescimento do robalo. Portanto, em um clima subtropical, recomenda-se começar a crescer na primavera (> 24°C) e evitar o manuseio de peixes quando a temperatura estiver abaixo de 20°C. A análise de regressão do peso final mostrou que densidades de 24 peixes m-3 podem ser indicadas para robalo nas condições deste estudo.(AU)