Age validation and contrasted growth performances of Pseudoplatystoma punctifer (Siluriformes: Pimelodidae) in two river systems of the Western Amazon

The doncella Pseudoplatystoma punctifer is an economically and ecologically important catfish in the Amazon basin. However, little is known about its age, growth and population dynamics parameters. This study aims to validate the formation of growth marks in vertebrae of individuals collected from two rivers systems of the Peruvian Amazon (Amazon-Marañón-Ucayali and Putumayo) and compare growth parameters using the von Bertalanffy growth function between sexes and systems. A total of 372 individuals from the Amazon-Marañón-Ucayali (AMU) system and 93 from the Putumayo River were analyzed. The formation of one growth ring per year was validated and the individual ages ranged from zero to nine years old. Females grew significantly larger than males in both systems. Both females and males grew significantly better in the AMU system than in the Putumayo River. Maximum observed length and size at maturity in the AMU system were lower than those reported in previous studies in the area, and together with an important proportion of juveniles in the catches, suggest that the species is heavily exploited. Further studies on the reproductive biology and population dynamics of the doncella are needed in order to implement management measures more in line with the current situation.(AU)

La doncella Pseudoplatystoma punctifer es un bagre de importancia económica y ecológica en la cuenca Amazonica. Pese a ello, poco se conoce acerca de parámetros de edad, crecimiento y dinámica poblacional. Este estudio tuvo como objetivo validar la formación de marcas de crecimiento en vértebras de individuos colectados en dos sistemas fluviales de la Amazonia Peruana (Amazonas-Marañón-Ucayali y Putumayo) y comparar los parámetros de crecimiento usando la función de von Bertalanffy entre sexos y sistemas. Fueron analizados 372 individuos del sistema Amazonas-Marañón-Ucayali (AMU) y 93 del Putumayo. Se validó la formación de un anillo de crecimiento por año, la edad osciló entre cero y nueve años. Las hembras fueron significativamente más grandes que los machos en ambos sistemas. Para ambos sexos el crecimiento fue significativamente mayor en el sistema AMU que en el Putumayo. Las máximas tallas y edades de primera madurez observadas en el sistema AMU fueron menores a las reportadas en estudios previos en el área, y junto con un considerable porcentaje de juveniles presentes en las capturas, se sugiere que la especie está siendo fuertemente explotada. Son necesarios estudios de biología reproductiva y dinámica poblacional de doncella para implementar medidas de manejo acordes a la situación actual.(AU)

Multivariate modeling strategies to predict nutritional requirements of essential amino acids in semiheavy second-cycle hens

An experiment with 23 diets was performed to evaluate the effect of digestible lysine (Lys), digestible methionine + cysteine (Met+Cys), and digestible threonine (Thr) on egg production of H&N Brown second-cycle laying hens (SCLH) for 20 weeks (92-111 weeks of age) in cages under environmental conditions. Body weight (BW), feed intake (FI), feed conversion ratio (FCR), egg weight (EW), number of hen-housed eggs, and livability were also evaluated during the experiment. Diets were formulated from a central composite design that combined five levels of Lys, Met+Cys, and Thr ranging from 727 to 1159, 662 to 1055, and 552 to 882 mg/kg, respectively. Egg production (EP) data were evaluated through three different modeling strategies: egg production models, multivariate polynomial models, and artificial neural networks (ANN). A cascade-forward neural network with logsigmoid transfer function was selected as the best model according to goodness-offit statistics in both identification and validation data. One of the best scenarios for EP of H&N Brown SCLH under specific outdoor conditions was established at Lys, Met+Cys, and Thr levels of 1138, 1031, and 717 mg/hen·day, respectively. The ANN model may be an appropriate tool to study and predict EP of H&N Brown SCLH based on the combination of three different levels of essential digestible amino acids. The strategies included in this work may contribute to improving poultry performance based on modeling techniques to study other production parameters in terms of different nutritional requirements and productive conditions.

Marking fin spine of juvenile sturgeon (Acipenseriformes: Acipenseridae) using oxytetracycline and the comparing of growth performance / [Marcação da espinha da nadadeira de esturjão juvenil (Acipenseriformes: Acipenseridae) usando-se oxitetraciclina e comparação do desempenho de crescimento]

This study aimed to describe and validate the formation of the rings in the spine of the pectoral fin and to determine the coherence of the OTC mark with the rings of three species of Caspian Sea sturgeon, the Persian sturgeon (Acipenser persicus), the Starry sturgeon (Acipenser stellatus) and Ship sturgeon (Acipenser nudiventris). Validation was achieved by comparing the total radius of the fin spine of fish of known age after one and two years of growth with the measured radius of the first and second rings in the zone. There was no overlap between the measured radius for the first year and the increase for the second. The Ship sturgeon showed the largest width of the second ring followed by the Persian sturgeon and Stellate sturgeon. The results indicate that the highest growth parameter belongs to the juvenile Ship sturgeon. This research showed that chemically marking the fin spines of juvenile Acipenseridae leads to unbiased estimates and contributes to the knowledge of the population dynamics of these species. The study found that the combination of the dial ring of the pectoral fin spine with growth validated the age estimation in juvenile sturgeon Ship, Persian, and Starry sturgeon.(AU)

O objetivo deste estudo foi descrever e validar a formação dos anéis na espinha da nadadeira peitoral de três espécies de esturjão do mar Cáspio: o esturjão-persa (Acipenser persicus), o esturjão-estrelado (Acipenser stellatus) e o esturjão-de-navio (Acipenser nudiventris), bem como determinar a coerência da marca OTC com os anéis dessas três espécies. A validação foi alcançada comparando-se o raio total da espinha da nadadeira de peixes de idade conhecida, após um e dois anos de crescimento, com o raio medido do primeiro e segundo anéis na zona. Não houve sobreposição entre o raio medido no primeiro ano e o aumento no segundo. O esturjão-de-navio mostrou a maior largura do segundo anel, seguido pelo esturjão-persa e pelo esturjão-estrelado. Os resultados indicam que o maior parâmetro de crescimento pertence ao esturjão-de-navio juvenil. Esta pesquisa mostrou que a marcação química dos espinhos das nadadeiras de juvenis de Acipenseridae leva a estimativas imparciais e contribui para o conhecimento da dinâmica populacional dessas espécies. O estudo descobriu que a combinação do anel do mostrador da barbatana peitoral espinhal com o crescimento validou a estimativa de idade em esturjão-de-navio juvenil, esturjão-persa e esturjão-estrelado.(AU)

Alternative light colors in suckling piglet creep area: preference and validation tests in swine maternity / Cores alternativas de luz de abrigos escamoteadores para leitões lactentes: teste de preferência e validação em maternidade suína

We performed a two-stage experiment: a preference and a validation test in swine litters, to determine whether suckling piglets preferred alternative light colors in their creep area over white light; we also determined whether the preferred color affected piglet behavior. In the first stage, five trials of two consecutive days were performed, each at 21-day intervals. In each trial, 40 piglets, from three to five days old, from four F1 sows (Large White x Landrace), were distributed in four treatments, in a paired scheme, receiving the following treatments: Treatment GR: white light vs. green light ; Treatment BL: white light vs. blue light; Treatment YE: yellow light vs. white light; Treatment RD: white light vs. red light. For the validation test, three consecutive lots of eight F1 sows (Large White x Landrace) and their corresponding maternity were used, remaining from birth under the influence of treatments T_Gr and T_Wh, totaling three replicates. T_Gr corresponded to four creep areaswith green LED light and T_Wh to four nurseries with white LED light. The piglets showed a significant preference only for white over blue. Among the alternative colors, piglets significantly preferred green. In the validation stage, there was no significant effect of colors on the mean percentage of permanence of the piglets inside the creep areas over all evaluated periods. Piglets between two and five days of age prefer green lighting;however,in the creep area, the light color used did not influence piglet behavior.(AU)

Foi realizado um experimento de duas etapas: teste de preferência e validação em maternidade suína, para verificar se leitões possuem preferência por cores alternativas de luz do abrigo escamoteador em relação à luz branca, e o efeito da cor de luz preferida em teste realizado em abrigos escamoteadores (cor alternativa e branca) no comportamento de leitões. Na primeira, foram realizados cinco ensaios de dois dias cada, em intervalos de 21 dias. Quarenta leitões, entre três e cinco dias de vida, provenientes de quatro matrizes F1 (Large White x Landrace), foram distribuídos em quatro tratamentos, em esquema pareado: Tratamento Vd: luz branca/luz verde; Tratamento Az: luz branca/luz azul; Tratamento Am: luz amarela/luz branca; Tratamento Vm: luz branca/luz vermelha. Para a validação, três lotes consecutivos de oito matrizes F1 (Large White x Landrace) e suas leitegadas permaneceram desde o nascimento sob os tratamentos T_Vd e T_Br. T_Vd correspondia a quatro escamoteadores com luz de LED verde e T_Br a quatro escamoteadores com luz de LED branca. A comparação entre cada cor alternativa e o branco mostrou diferença quanto à preferência (p 0,05) apenas para o azul. Entre as cores alternativas os leitões preferem a cor verde (p 0,05). Na etapa de validação, não houve efeito (p>0,05) no percentual médio de permanência dos leitões no interior dos escamoteadores, entre as cores de luz, para todos os períodos avaliados. Leitões entre dois a cinco dias de vida preferem a iluminação verde, porém no ambiente de maternidade, a cor de luz utilizada não influenciou no comportamento dos leitões.(AU)

Artificial neural networks on eggs production data management

Background: Eggs have acquired a greater importance as an inexpensive and high-quality protein. The Brazilian eggindustry has been characterized by a constant production expansion in the last decade, increasing the number of housedanimals and facilitating the spread of many diseases. In order to reduce the sanitary and financial risks, decisions regarding the production and the health status of the flock must be made based on objective criteria. The use of Artificial NeuralNetworks (ANN) is a valuable tool to reduce the subjectivity of the analysis. In this context, the aim of this study was atvalidating the ANNs as viable tool to be employed in the prediction and management of commercial egg production flocks.Materials, Methods & Results: Data from 42 flocks of commercial layer hens from a poultry company were selected. Thedata refer to the period between 2010 and 2018 and it represents a total of 600,000 layers. Six parameters were selectedas “output” data (number of dead birds per week, feed consumption, number of eggs, weekly weight, weekly egg production and flock uniformity) and a total of 13 parameters were selected as “input” data (flock age, flock identification, totalhens in the flock, weekly weight, flock uniformity, lineage, weekly mortality, absolute number of dead birds, eggs/hen,weekly egg production, feed consumption, flock location, creation phase). ANNs were elaborated by software programsNeuroShell Predictor and NeuroShell Classifier. The programs identified input variables for the assembly of the networksseeking the prediction of the variables called outgoing that are subsequently validated. This validation goes through thecomparison between the predictions and the real data present in the database that was the basis for the work. Validation ofeach ANN is expressed by the specific statistical parameters multiple determination (R2) and Mean Squared Error...

Artificial neural networks on eggs production data management

Background: Eggs have acquired a greater importance as an inexpensive and high-quality protein. The Brazilian eggindustry has been characterized by a constant production expansion in the last decade, increasing the number of housedanimals and facilitating the spread of many diseases. In order to reduce the sanitary and financial risks, decisions regarding the production and the health status of the flock must be made based on objective criteria. The use of Artificial NeuralNetworks (ANN) is a valuable tool to reduce the subjectivity of the analysis. In this context, the aim of this study was atvalidating the ANNs as viable tool to be employed in the prediction and management of commercial egg production flocks.Materials, Methods & Results: Data from 42 flocks of commercial layer hens from a poultry company were selected. Thedata refer to the period between 2010 and 2018 and it represents a total of 600,000 layers. Six parameters were selectedas “output” data (number of dead birds per week, feed consumption, number of eggs, weekly weight, weekly egg production and flock uniformity) and a total of 13 parameters were selected as “input” data (flock age, flock identification, totalhens in the flock, weekly weight, flock uniformity, lineage, weekly mortality, absolute number of dead birds, eggs/hen,weekly egg production, feed consumption, flock location, creation phase). ANNs were elaborated by software programsNeuroShell Predictor and NeuroShell Classifier. The programs identified input variables for the assembly of the networksseeking the prediction of the variables called outgoing that are subsequently validated. This validation goes through thecomparison between the predictions and the real data present in the database that was the basis for the work. Validation ofeach ANN is expressed by the specific statistical parameters multiple determination (R2) and Mean Squared Error...(AU)

Relationship between early finishing and reduced prevalence of cysticercosis in cattle / Relação da precocidade de terminação e a redução da prevalência de cisticercose em bovinos

This study aimed to group cattle carcasses with similar characteristics to assess the group-specific prevalence of cysticercosis using data from the slaughter of 15,002 cattle. The following variables were recorded: carcass weight, cover fat, individual age, and prevalence of cysticercosis. A k-means clustering method was used to examine the relationship between carcass characteristics and the prevalence of cysticercosis. We did not specify the number of clusters before the analyses but used automatic methods based on a cross-validation to select the best-fitting clusters. One of the three produced clusters included carcass weight, cover fat, and age, as desired by the Brazilian meat industry. This cluster showed a reduced prevalence of cysticercosis (P = 0.0147) and earlier finishing compared with the other groups. In conclusion, earlier finishing seems to be associated with a lower prevalence of bovine cysticercosis.

Este estudo objetivou agrupar carcaças de bovinos com características semelhantes para avaliar a prevalência de cisticercose específica do grupo, utilizando dados do abate de 15.002 bovinos. As seguintes variáveis foram registradas: peso de carcaça, gordura de cobertura, idade individual e prevalência de cisticercose. Um método de agrupamento k-means foi usado para examinar a relação das características de carcaça e a prevalência de cisticercose. Não se especificou o número de clusters antes das análises, utilizaram-se métodos automáticos com base em uma validação cruzada para selecionar os clusters mais adequados. Um dos três clusters produzidos possuiu peso de carcaça, gordura de cobertura e idade, conforme desejado pela indústria de carnes brasileira. Este cluster mostrou uma menor prevalência de cisticercose (P = 0,0147) e maior precocidade de terminação em comparação com os outros grupos. Conclui-se que a precocidade de terminação está associada a uma menor prevalência de cisticercose bovina.

Relationship between early finishing and reduced prevalence of cysticercosis in cattle / Relação da precocidade de terminação e a redução da prevalência de cisticercose em bovinos

This study aimed to group cattle carcasses with similar characteristics to assess the group-specific prevalence of cysticercosis using data from the slaughter of 15,002 cattle. The following variables were recorded: carcass weight, cover fat, individual age, and prevalence of cysticercosis. A k-means clustering method was used to examine the relationship between carcass characteristics and the prevalence of cysticercosis. We did not specify the number of clusters before the analyses but used automatic methods based on a cross-validation to select the best-fitting clusters. One of the three produced clusters included carcass weight, cover fat, and age, as desired by the Brazilian meat industry. This cluster showed a reduced prevalence of cysticercosis (P = 0.0147) and earlier finishing compared with the other groups. In conclusion, earlier finishing seems to be associated with a lower prevalence of bovine cysticercosis.(AU)

Este estudo objetivou agrupar carcaças de bovinos com características semelhantes para avaliar a prevalência de cisticercose específica do grupo, utilizando dados do abate de 15.002 bovinos. As seguintes variáveis foram registradas: peso de carcaça, gordura de cobertura, idade individual e prevalência de cisticercose. Um método de agrupamento k-means foi usado para examinar a relação das características de carcaça e a prevalência de cisticercose. Não se especificou o número de clusters antes das análises, utilizaram-se métodos automáticos com base em uma validação cruzada para selecionar os clusters mais adequados. Um dos três clusters produzidos possuiu peso de carcaça, gordura de cobertura e idade, conforme desejado pela indústria de carnes brasileira. Este cluster mostrou uma menor prevalência de cisticercose (P = 0,0147) e maior precocidade de terminação em comparação com os outros grupos. Conclui-se que a precocidade de terminação está associada a uma menor prevalência de cisticercose bovina.(AU)

Development and evaluation of prediction equations for methane emission from Nellore cattle

Dry matter intake (DMI), nutrient intake and enteric CH4 emission were evaluated in 48 Nellore cattle (392 ± 27 days of age). Equations were generated from intake data and evaluated using root mean square prediction error (RMSPE), and validated by cross-validation. Equations that included DMI and hemicellulose intake (HEMI) [ CH4(MJd−1)=4.08(±1.65)+11.6(±2.34)DMI(kgd−1)−33.4(±7.21)HEMI(kgd−1)] ; DMI and total carbohydrate intake (TCHI) [CH4(MJd−1)=5.26(±1.69)−6.3(±1.47)DMI(kgd−1)+8.8(±1.81)TCI(kgd−1)]; metabolizable energy intake (MEI) and cellulose intake (CELI) [CH4(MJd−1)=5.16(±1.72)−0.13(±0.048)MEI(MJd−1)+7.37(±1.53)CELI(kgd−1)] , and non-fiber carbohydrate intake (NFCI) [CH4(MJd−1)=3.14(±1.48)+3.65(±1.05)NFCI(kgd−1)] resulted in the lowest RMSPE (14.3, 14.1, 14.3 and 14.7%, respectively). When literature equations were evaluated using our database, the most accurate predictions were obtained with equations that included DMI and lignin intake (RMSPE = 15.27%) and MEI, acid detergent fiber intake and lignin intake (RMSPE = 15.7%). The mean error of predicting enteric CH4 emission with the equations developed in this study based on DMI and nutrient intake is 17% and the most accurate predictions are obtained with equations including DMI, carbohydrate intake and MEI.(AU)  

Development and evaluation of prediction equations for methane emission from Nellore cattle

Dry matter intake (DMI), nutrient intake and enteric CH4 emission were evaluated in 48 Nellore cattle (392 ± 27 days of age). Equations were generated from intake data and evaluated using root mean square prediction error (RMSPE), and validated by cross-validation. Equations that included DMI and hemicellulose intake (HEMI) [ CH4(MJd−1)=4.08(±1.65)+11.6(±2.34)DMI(kgd−1)−33.4(±7.21)HEMI(kgd−1)] ; DMI and total carbohydrate intake (TCHI) [CH4(MJd−1)=5.26(±1.69)−6.3(±1.47)DMI(kgd−1)+8.8(±1.81)TCI(kgd−1)]; metabolizable energy intake (MEI) and cellulose intake (CELI) [CH4(MJd−1)=5.16(±1.72)−0.13(±0.048)MEI(MJd−1)+7.37(±1.53)CELI(kgd−1)] , and non-fiber carbohydrate intake (NFCI) [CH4(MJd−1)=3.14(±1.48)+3.65(±1.05)NFCI(kgd−1)] resulted in the lowest RMSPE (14.3, 14.1, 14.3 and 14.7%, respectively). When literature equations were evaluated using our database, the most accurate predictions were obtained with equations that included DMI and lignin intake (RMSPE = 15.27%) and MEI, acid detergent fiber intake and lignin intake (RMSPE = 15.7%). The mean error of predicting enteric CH4 emission with the equations developed in this study based on DMI and nutrient intake is 17% and the most accurate predictions are obtained with equations including DMI, carbohydrate intake and MEI.

Life-history characteristics of Pseudoplatystoma metaense (Teleostei: Siluriformes: Pimelodidae) from the northwestern Orinoco River Basin

The tiger shovelnose catfish (Pseudoplatystoma metaense) identified in literature prior to 2007 as P. tigrinum is the most important catfish species in the Orinoco River fishery, because of its abundance and high market price. The aim of this study was to obtain age, growth and population parameters of the of tiger shovelnose catfish. A total of 2,183 catfish, were sampled during 1996-2003 from the commercial fishery of the northwestern Orinoco River Basin in Venezuela, and were aged by examination of otoliths. Validation of otolith annuli was achieved with marginal increment analysis. Results suggest that, the opaque and translucent zones of otoliths were formed once per year. Length-weight relation and the von Bertalanffy growth model parameters were used to evaluate growth and other population parameters. A strong link between the annual flood pulse and opaque zone formation was confirmed in tiger shovelnose catfish. The total mortality (Z) and natural mortality (M) were estimated. Based in the reference points for optimal and limit fishing mortality rates (F opt and F limit ) this species is exploited above optimum levels. We thus recommend a closed fishing season during their seasonal reproduction, and establishment of a system of fish refuges to help sustain the population.(AU)

O bagre capararí (Pseudoplatystoma metaense) identificado na literatura antes de 2007 como P. tigrinum é uma das espécies de bagres mais importantes da pesca no noroeste do rio Orinoco, por sua abundância e alto preço de comercialização no mercado. O objetivo deste estudo foi obter parâmetros populacionais sobre a idade e crescimento do bagre capararí. Um total de 2.183 exemplares de P. metaense foram examinados desde 1996 até 2003, coletados da frota comercial artesanal do rio Apure na Venezuela. A idade foi determinada pela examinação dos otólitos. A validação da idade foi estimada com a análise de incremento marginal. As zonas opacas e translúcidas dos otólitos foram formada anualmente. A relação comprimento-peso e a equação de von Bertalanffy foram usadas para avaliar o crescimento e outros parâmetros populacionais. Uma forte relação entre o pulso anual de inundação e a formação de zonas opacas foi confirmada em P. metaense. A mortalidade total (Z) e a mortalidade natural (M) foram estimadas. Portanto, baseado nos pontos de referência biológicos (F opt e F lim ) esta espécie encontra-se sobreexplotada acima do nível ótimo. Recomenda-se que o período de defeso deva ser sincronizado com o período de reprodução da espécie e um sistema de reservas de pesca deveria ser utilizado para ajudar a sustentabilidade da população.(AU)

Age and growth of the Amazonian migratory catfish Brachyplatystoma rousseauxii in the Madeira River basin before the construction of dams

The goliath catfish Brachyplatystoma rousseauxii has crucial economical and ecological functions in the Amazon basin. Although its life history characteristics have been studied in the Amazon, there is little information in the Madeira River basin, which holds genetically distinct populations and where dams were recently built. Using fish collected in Bolivia, Brazil and Peru, this study provides a validation of growth rings deposition and details the growth patterns of B. rousseauxii in the Madeira before the dams' construction. Age structure and growth parameters were determined from 497 otolith readings. The species exhibits two growth rings per year and sampled fish were between 0 and 16 years old. In the Brazilian portion of the basin, mainly young individuals below 5 years old were found, whereas older fish (> 5 years) were caught only in the Bolivian and Peruvian stretches, indicating that after migrating upstream to reproduce, adults remain in the headwaters of the Madeira River. Comparing with previous publications, B. rousseauxii had a slower growth and 20 cm lower maximum standard length in the Madeira River than in the Amazon River. This study provides a baseline for future evaluation of changes in population dynamics of the species following dams closure.(AU)

Brachyplatystoma rousseauxii é um bagre de importante papel econômico e ecológico na bacia amazônica. Embora existam estudos acerca de sua história de vida na Amazônia, há pouca informação para a bacia do rio Madeira, onde existem populações geneticamente distintas e recentemente foram construídas duas usinas hidrelétricas. Este estudo validou a deposição das marcas de crescimento e detalhou os padrões de desenvolvimento dessa espécie no rio Madeira, antes da construção das barragens. As coletas abrangeram os territórios brasileiro, boliviano e peruano, com estrutura etária e parâmetros de crescimento determinados a partir de 497 otólitos. Foram observadas duas marcas de crescimento por ano e indivíduos entre 0 e 16 anos. Na porção brasileira foram encontrados principalmente jovens menores de 5 anos, enquanto que os peixes mais velhos (> 5 anos) foram capturados apenas na Bolívia e Peru, indicando que após a migração reprodutiva, os adultos permanecem nas cabeceiras do rio Madeira. Comparando com estudos prévios realizados na calha principal do rio Amazonas, B. rousseauxii apresentou crescimento mais lento e comprimento padrão máximo inferior de 20 cm no rio Madeira. Este estudo fornece uma base para a avaliação futura das mudanças na dinâmica populacional desse espécie após o implementação das barragens.(AU)

Life-history characteristics of Pseudoplatystoma metaense (Teleostei: Siluriformes: Pimelodidae) from the northwestern Orinoco River Basin

The tiger shovelnose catfish (Pseudoplatystoma metaense) identified in literature prior to 2007 as P. tigrinum is the most important catfish species in the Orinoco River fishery, because of its abundance and high market price. The aim of this study was to obtain age, growth and population parameters of the of tiger shovelnose catfish. A total of 2,183 catfish, were sampled during 1996-2003 from the commercial fishery of the northwestern Orinoco River Basin in Venezuela, and were aged by examination of otoliths. Validation of otolith annuli was achieved with marginal increment analysis. Results suggest that, the opaque and translucent zones of otoliths were formed once per year. Length-weight relation and the von Bertalanffy growth model parameters were used to evaluate growth and other population parameters. A strong link between the annual flood pulse and opaque zone formation was confirmed in tiger shovelnose catfish. The total mortality (Z) and natural mortality (M) were estimated. Based in the reference points for optimal and limit fishing mortality rates (F opt and F limit ) this species is exploited above optimum levels. We thus recommend a closed fishing season during their seasonal reproduction, and establishment of a system of fish refuges to help sustain the population.(AU)

O bagre capararí (Pseudoplatystoma metaense) identificado na literatura antes de 2007 como P. tigrinum é uma das espécies de bagres mais importantes da pesca no noroeste do rio Orinoco, por sua abundância e alto preço de comercialização no mercado. O objetivo deste estudo foi obter parâmetros populacionais sobre a idade e crescimento do bagre capararí. Um total de 2.183 exemplares de P. metaense foram examinados desde 1996 até 2003, coletados da frota comercial artesanal do rio Apure na Venezuela. A idade foi determinada pela examinação dos otólitos. A validação da idade foi estimada com a análise de incremento marginal. As zonas opacas e translúcidas dos otólitos foram formada anualmente. A relação comprimento-peso e a equação de von Bertalanffy foram usadas para avaliar o crescimento e outros parâmetros populacionais. Uma forte relação entre o pulso anual de inundação e a formação de zonas opacas foi confirmada em P. metaense. A mortalidade total (Z) e a mortalidade natural (M) foram estimadas. Portanto, baseado nos pontos de referência biológicos (F opt e F lim ) esta espécie encontra-se sobreexplotada acima do nível ótimo. Recomenda-se que o período de defeso deva ser sincronizado com o período de reprodução da espécie e um sistema de reservas de pesca deveria ser utilizado para ajudar a sustentabilidade da população.(AU)

Age and growth of the Amazonian migratory catfish Brachyplatystoma rousseauxii in the Madeira River basin before the construction of dams

The goliath catfish Brachyplatystoma rousseauxii has crucial economical and ecological functions in the Amazon basin. Although its life history characteristics have been studied in the Amazon, there is little information in the Madeira River basin, which holds genetically distinct populations and where dams were recently built. Using fish collected in Bolivia, Brazil and Peru, this study provides a validation of growth rings deposition and details the growth patterns of B. rousseauxii in the Madeira before the dams' construction. Age structure and growth parameters were determined from 497 otolith readings. The species exhibits two growth rings per year and sampled fish were between 0 and 16 years old. In the Brazilian portion of the basin, mainly young individuals below 5 years old were found, whereas older fish (> 5 years) were caught only in the Bolivian and Peruvian stretches, indicating that after migrating upstream to reproduce, adults remain in the headwaters of the Madeira River. Comparing with previous publications, B. rousseauxii had a slower growth and 20 cm lower maximum standard length in the Madeira River than in the Amazon River. This study provides a baseline for future evaluation of changes in population dynamics of the species following dams closure.(AU)

Brachyplatystoma rousseauxii é um bagre de importante papel econômico e ecológico na bacia amazônica. Embora existam estudos acerca de sua história de vida na Amazônia, há pouca informação para a bacia do rio Madeira, onde existem populações geneticamente distintas e recentemente foram construídas duas usinas hidrelétricas. Este estudo validou a deposição das marcas de crescimento e detalhou os padrões de desenvolvimento dessa espécie no rio Madeira, antes da construção das barragens. As coletas abrangeram os territórios brasileiro, boliviano e peruano, com estrutura etária e parâmetros de crescimento determinados a partir de 497 otólitos. Foram observadas duas marcas de crescimento por ano e indivíduos entre 0 e 16 anos. Na porção brasileira foram encontrados principalmente jovens menores de 5 anos, enquanto que os peixes mais velhos (> 5 anos) foram capturados apenas na Bolívia e Peru, indicando que após a migração reprodutiva, os adultos permanecem nas cabeceiras do rio Madeira. Comparando com estudos prévios realizados na calha principal do rio Amazonas, B. rousseauxii apresentou crescimento mais lento e comprimento padrão máximo inferior de 20 cm no rio Madeira. Este estudo fornece uma base para a avaliação futura das mudanças na dinâmica populacional desse espécie após o implementação das barragens.(AU)

Haematological and Biochemical Profile of Balb-c Mice

Background: Animal models are widely used in scientific research because of the ability to generate information from an organism like everything under a given experimental condition. Hematological and biochemical tests in laboratory animals are essential for the validation of several scientific studies. In addition, it standardizes physiological values   for these animals according to their sex, age, lineage, environment, and nutritional status. The present work aims to establish reference values   for biochemical and hematological standards in Balb/c mice, for males and females.Materials, Methods & Results: A total of 50 male and female mice were used at reproductive age. The procedures for collecting, processing, and analyzing the samples were standardized.  The collected blood samples were immediately transferred to eppendorf tubes containing heparin, and intended for hematological and biochemical evaluation. The hematological evaluation consisted of Red blood cell count (RBC), Leukocyte counts (WBC), Platelet counts (PLT), Hematocrit (HCT), Hemoglobin concentration (HGB), Mean corpuscular volume (MCV), and Mean corpuscular hemoglobin concentration (MCHC). Already the quantified biochemical parameters were: urea, creatinine, alanina aminotransaminase (ALT), aspartato aminotransaminase (AST) and fosfatase alcalina (FAL). The differential leukocyte count was also performed

Imputation of genetic composition for missing pedigree data in Serrasalmidae using morphometric data

This study aimed to impute the genetic makeup of individual fishes of Serrasalmidae family on the basis of body weight and morphometric measurements. Eighty-three juveniles, belonging to the genetic groups Pacu, Pirapitinga, Tambaqui, Tambacu, Tambatinga, Patinga, Paqui and Piraqui, were separated into 16 water tanks in a recirculation system, with two tanks per genetic group, where they remained until they reached 495 days of age. They were then weighed and analyzed according to the following morphometric parameters: Standard Length (SL), Head Length (HL), Body Height (BH), and Body Width (BW). The identity of each fish was confirmed with two SNPs and two mitochondrial markers. Two analyses were performed: one for the validating the imputation and another for imputing a genetic composition of animals considered to be advanced hybrids (post F1). In both analyses, we used linear mixed models with a mixture of normal distributions to impute the genetic makeup of the fish based on phenotype. We applied the mixed models method, whereby the environmental effects were estimated by the Empirical Best Linear Unbiased Estimator (EBLUE) and genetic effects are considered random, obtaining the Empirical Best Linear Unbiased Predictor (EBLUP) from the general (GCA) and the specific (SCA) combining ability effects. The results showed that validation of the genetic makeup imputation based on body weight can be used because of the strong correlation between the observed and imputed genotype. The fish classified as advanced hybrids had a genetic composition with a high probability of belonging to known genotypes and there was consistency in genotype imputation according to the different characteristics used.

Imputation of genetic composition for missing pedigree data in Serrasalmidae using morphometric data

This study aimed to impute the genetic makeup of individual fishes of Serrasalmidae family on the basis of body weight and morphometric measurements. Eighty-three juveniles, belonging to the genetic groups Pacu, Pirapitinga, Tambaqui, Tambacu, Tambatinga, Patinga, Paqui and Piraqui, were separated into 16 water tanks in a recirculation system, with two tanks per genetic group, where they remained until they reached 495 days of age. They were then weighed and analyzed according to the following morphometric parameters: Standard Length (SL), Head Length (HL), Body Height (BH), and Body Width (BW). The identity of each fish was confirmed with two SNPs and two mitochondrial markers. Two analyses were performed: one for the validating the imputation and another for imputing a genetic composition of animals considered to be advanced hybrids (post F1). In both analyses, we used linear mixed models with a mixture of normal distributions to impute the genetic makeup of the fish based on phenotype. We applied the mixed models method, whereby the environmental effects were estimated by the Empirical Best Linear Unbiased Estimator (EBLUE) and genetic effects are considered random, obtaining the Empirical Best Linear Unbiased Predictor (EBLUP) from the general (GCA) and the specific (SCA) combining ability effects. The results showed that validation of the genetic makeup imputation based on body weight can be used because of the strong correlation between the observed and imputed genotype. The fish classified as advanced hybrids had a genetic composition with a high probability of belonging to known genotypes and there was consistency in genotype imputation according to the different characteristics used.(AU)

Perfil hematológico e bioquímico de camundongos da linhagem Balb-c / Haematological and biochemical profile of Balb-c Mice

Background: Animal models are widely used in scientific research because of the ability to generate information from an organism like everything under a given experimental condition. Hematological and biochemical tests in laboratory animals are essential for the validation of several scientific studies. In addition, it standardizes physiological values for these animals according to their sex, age, lineage, environment, and nutritional status. The present work aims to establish reference values for biochemical and hematological standards in Balb/c mice, for males and females.Materials, Methods & Results: A total of 50 male and female mice were used at reproductive age. The procedures for collecting, processing, and analyzing the samples were standardized. The collected blood samples were immediately transferred to eppendorf tubes containing heparin, and intended for hematological and biochemical evaluation. The hematological evaluation consisted of Red blood cell count (RBC), Leukocyte counts (WBC), Platelet counts (PLT), Hematocrit (HCT), Hemoglobin concentration (HGB), Mean corpuscular volume (MCV), and Mean corpuscular hemoglobin concentration (MCHC). Already the quantified biochemical parameters were: urea, creatinine, alanina aminotransaminase (ALT), aspartato aminotransaminase (AST) and fosfatase alcalina (FAL). The differential leukocyte count was also performed. Hematological results obtained for males and females were: 9.19 ± 3.35 (106/mm³) and 7.3 ± 2.01(106/mm³) of RBC; 35.8 ± 6.7% and 38.44 ± 3.93% of HCT; 11.51 ± 2.17 g/dL and 11.85 ± 1.56 g/dL of HGB; 45.83 ± 15.03 fL and 60.26 ± 18.25 fL of VCM; 31.80 ± 1.15% and 31.88 ± 0.99% of MCHC; and, 5380 ± 1994.21(10³/mm³) and 3564 ± 1071(10³/mm³) of WBC. The platelet counts were 878.92 ± 84.19 and 678.28 ± 227.21, for males and females respectively.[...]

Perfil hematológico e bioquímico de camundongos da linhagem Balb-c / Haematological and biochemical profile of Balb-c Mice

Background: Animal models are widely used in scientific research because of the ability to generate information from an organism like everything under a given experimental condition. Hematological and biochemical tests in laboratory animals are essential for the validation of several scientific studies. In addition, it standardizes physiological values for these animals according to their sex, age, lineage, environment, and nutritional status. The present work aims to establish reference values for biochemical and hematological standards in Balb/c mice, for males and females.Materials, Methods & Results: A total of 50 male and female mice were used at reproductive age. The procedures for collecting, processing, and analyzing the samples were standardized. The collected blood samples were immediately transferred to eppendorf tubes containing heparin, and intended for hematological and biochemical evaluation. The hematological evaluation consisted of Red blood cell count (RBC), Leukocyte counts (WBC), Platelet counts (PLT), Hematocrit (HCT), Hemoglobin concentration (HGB), Mean corpuscular volume (MCV), and Mean corpuscular hemoglobin concentration (MCHC). Already the quantified biochemical parameters were: urea, creatinine, alanina aminotransaminase (ALT), aspartato aminotransaminase (AST) and fosfatase alcalina (FAL). The differential leukocyte count was also performed. Hematological results obtained for males and females were: 9.19 ± 3.35 (106/mm³) and 7.3 ± 2.01(106/mm³) of RBC; 35.8 ± 6.7% and 38.44 ± 3.93% of HCT; 11.51 ± 2.17 g/dL and 11.85 ± 1.56 g/dL of HGB; 45.83 ± 15.03 fL and 60.26 ± 18.25 fL of VCM; 31.80 ± 1.15% and 31.88 ± 0.99% of MCHC; and, 5380 ± 1994.21(10³/mm³) and 3564 ± 1071(10³/mm³) of WBC. The platelet counts were 878.92 ± 84.19 and 678.28 ± 227.21, for males and females respectively.[...](AU)

Validation of body condition score system in Holstein x Zebu cows via ultrasound method during the transition period and early lactation / Validação por ultrassonografia da condição corporal em vacas mestiças Holandês x Zebu durante o período de transição e fase inicial de lactação

This study aims to validate, by means of subcutaneous rump fat thickness (RFT), the suitability of the visual evaluation of body condition score (BCS) to indicate the body condition of crossbred dairy cows (Holstein x Zebu) during the transition period and early lactation. Animals were selected according to lactation period and distributed into three groups: PP (0 to 4 weeks antepartum; n = 30), L4 (0 to 4 weeks postpartum; n = 15), and L + 5 (5 to 14 weeks postpartum; n = 63). The relationship among RFT, BCS, and body weight (BW) was investigated using correlation and regression analyses. The variables BCS, RFT, and BW were different among the three groups (P 0.05). The correlations between BCS and RFT were higher in groups PP and L + 5 (r = 0.78 and r = 0.71 respectively). However, the L4 group showed a weak correlation (r = -0.04). The regression models were able to explain how much RFT varies because of changes in BCS, with coefficients of determination equal to 0.61 for PP and 0.51 for L + 5 group. In conclusion, BCS can be considered a good predictor of RFT for crossbred Holstein x Zebu cows in antepartum and postpartum for over 5 weeks of lactation.

Objetivou-se verificar por meio da espessura de gordura subcutânea na garupa (EGG) se o método de avaliação visual de escore de condição corporal (ECC) é apropriado para indicar a condição corporal de vacas leiteiras mestiças Holandês x Zebu no período de transição e fase inicial de lactação. Os animais foram selecionados de acordo com estágio de lactação e foram divididos em três grupos: grupo PP (4 a 0 semanapré-parto; n=30); grupo L4 (0 a 4 semanas pós-parto; n = 15); grupo L+5 (5 a 14 semanas pós-parto; n = 63). As variáveis ECC, EGG e BW variaram entre os três grupos (P 0,05). As correlações entre ECC e EGG foram maiores nos grupos PP e L+5, com r² = 0,78 e r² = 0,71, respectivamente. O grupo L4 apresentou fraca correlação com r = -0,04. Os modelos de regressão foram capazes de explicar o quanto da variação de EGG é devido à variação de ECC, com resultados de coeficientes de determinação igual a 0,61 para o grupo PP e 0,51 para o grupo L+5. Em conclusão, para os animais do pré-parto e do pós-parto com mais de cinco semanas de lactação o ECC pode ser considerado um bom preditor da EGG.