Na contramão das teses da sociedade pós-industrial, o artigo desenvolve o argumento de que as plataformas digitais sintetizam contemporaneamente a radicalização e o espraiamento da lógica produtiva industrial. Ao analisar o capitalismo de plataforma e os mecanismos de externalização da produção, considera que as plataformas são apenas a ponta do iceberg e a comprovação empírica do desenvolvimento da lógica industrial, da produção de mercadorias (produto ou serviço, material e/ou imaterial, tangível ou intangível). Trata-se, assim, de um capitalismo industrial de plataforma. Com esse processo em curso, observa-se a tendência de espraiamento da plataformização do trabalho e suas formas de exploração de trabalho, de relações de trabalho destituídas de direitos que, por sua vez, encontram resistência nas lutas dos trabalhadores e trabalhadoras que desnudam a faceta perversa do trabalho plataformizado.

Contrary to the theses of post-industrial society, this article argues that digital platforms simultaneously synthesize the radicalization and spread of industrial productive logic. When analyzing platform capitalism and its mechanisms of product externalization, the text considers platforms as just the tip of the iceberg and empirical evidence of the development of industrial logic, of the production of goods (product or service, material and/or immaterial, tangible or intangible). It is, therefore, an industrial platform capitalism . As an ongoing process, it tends to spread labor platformization and its conditions of labor exploitation, disenfranchised labor relations that, in turn, face resistance by the workers, laying bare the perversion of platformized work.

Contrairement aux thèses de la société post-industrielle, cet article soutien que les plateformes numériques synthétisent à la fois la radicalisation et la diffusion de la logique productive industrielle. En analysant le capitalisme de plateforme et ses mécanismes d’externalisation des produits, le text considère que les plateformes ne sont que la partie émergée de l’iceberg et la preuve empirique du développement de la logique industrielle, de la production de biens (produit ou service, matériel et/ou immatériel, tangible ou intangible). Il s’agit donc d’un capitalisme industriel de plateforme. en tant que processus continu, il tend à étendre le travail de plateforme et ses formes d’exploitation du travail, des relations de travail dépourvues de droits qui, à leur tour, sont combattues par les ouvrières qui exposent la facette perverse du travail de plateforme.

RESUMO: O objetivo deste estudo foi avaliar dois aditivos alimentares, um a base de butirato de sódio encapsulado (Adimix® Precision) (AD) e outro a base de um fitogênico (Apex® 5) (AX), associados ou não a um antibiótico promotor de crescimento (tilosina), durante as fases de crescimento e terminação, sobre o desempenho, características da carcaça e status de saúde. Foram utilizados 300 suínos machos castrados e fêmeas distribuídos em seis tratamentos em um delineamento em blocos casualizados com dez repetições. Os tratamentos consistiram em um controle negativo (CN), controle positivo (CP) (tilosina), AD (butirato de sódio encapsulado), AX (fitogênico), CP+AD (tilosina+butirato de sódio encapsulado) e CP+AX (tilosina+fitogênico). Os dados de desempenho (peso vivo, consumo diário de ração, ganho de peso médio diário e conversão alimentar) e de carcaça (peso de carcaça, espessura de toucinho, profundidade do lombo e carne magra na carcaça) foram submetidos à ANOVA seguido por teste de Tukey, e os dados de condição de saúde (ocorrência de doenças, animais eutanasiados e mortos espontaneamente) foram analisados pelo teste de χ2. Os animais do grupo AD apresentaram maior ganho de peso diário (GPD) durante o período de avaliação e maior peso vivo aos 120, 140 e 164 dias de idade, além de maior peso de carcaça em comparação aos grupos CN e CP. O tratamento AX aumentou o GPD na fase crescimento II e o peso vivo aos 120 e 140 dias de idade em relação ao CN. O grupo CP+AX apresentou maior peso final em relação aos grupos CN e CP e maior peso de carcaça em relação ao CN. Não houve diferença entre os tratamentos para espessura de toucinho, porcentagem de carne magra na carcaça e ocorrência de doenças e óbitos. A inclusão de butirato de sódio encapsulado (tratamento AD) foi efetiva no aumento de GPD, peso final e peso de carcaça em comparação à suplementação com tilosina (tratamento CP), assim como a inclusão fitogênico (tratamento AX) melhorou a conversão alimentar em comparação ao grupo CP.

ABSTRACT: The aim of this study was to evaluate two feed additives, one based on encapsulated sodium butyrate (Adimix® Precision) (AD) and the other, a phytogenic (Apex® 5) (AX), associated or not with an antimicrobial growth promoter (tylosin) during the growth and finishing phases on performance, carcass characteristics and health conditions. A total of 300 barrows and females were distributed in six treatments in a randomized block design with ten replicates. The treatments consisted of a negative control (NC), positive control (PC) (tylosin), AD (encapsulated sodium butyrate), AX (phytogenic), PC+AD (tylosin+encapsulated sodium butyrate), and PC+AX (tylosin+phytogenic). The performance (live weight, daily feed intake, average daily gain and feed conversion) and carcass data (carcass weight, backfat thickness, loin depth, lean meat on the carcass) were submitted to ANOVA plus Tukey’s test, and the health conditions (occurrence of diseases, culling, and spontaneous deaths) were analyzed by χ2. Animals of the AD group had the highest average daily gain (ADG) over the evaluation period and the highest live weight at 120, 140, and 164 days of age, in addition to the highest carcass weight compared to NC and PC groups. The AX treatment increased the ADG in growth phase II and the live weight at 120 and 140 days of age in relation to the NC. The PC+AX group had a higher final live weight compared to the NC and PC groups and higher carcass weight in relation to the NC group. There was no difference among treatments for backfat thickness, percentage of lean meat in the carcass, or occurrence of diseases and deaths. The inclusion of encapsulated sodium butyrate (AD treatment) was effective in increasing ADG, final live weight, and carcass weight compared to supplementation with tylosin (PC treatment), as was the inclusion of a phytogenic (AX treatment) on FC compared to the PC.

Abstract The potential of near-infrared spectroscopy (NIRS) to predict the physicochemical characteristics of the porcine longissimus dorsi (LD) muscle was evaluated in comparison to the standard methods of pH and color for meat quality analysis compared to the pH results with Colorimeter and pH meter. Spectral information from each sample (n = 77) was obtained as the average of 32 successive scans acquired over a spectral range from 400 - 2498 nm with a 2 - nm gap for calibration and validation models. Partial least squares (PLS) regression was used for each individual model. An R2 and a residual predictive deviation (RPD) of 0.67/1.7, 0.86/2, and 0.76/1.9 were estimated for color parameters L*, a *, and b*, respectively. Final pH had an R2 of 0.67 and a RPD of 1.6. NIRS showed great potential to predict color parameter a * of porcine LD muscle. Further studies with larger samples should help improve model quality.

Resumo Introdução: O objetivo deste estudo foi comparar os pacientes com transtorno bipolar (TB), seus familiares de primeiro grau e um grupo de controles saudáveis em termos de uso de estratégias adaptativas e não adaptativas, explorando diferenças entre tipos específicos de estratégias e suas correlações com variáveis clínicas. Métodos: Estudo transversal, envolvendo 36 pacientes com TB eutímicos, 39 familiares de primeiro grau e 44 controles. As estratégias de enfrentamento foram avaliadas usando a escala Brief COPE. Resultados: Foram detectadas diferenças significativas no uso de estratégias adaptativas e não adaptativas por pacientes, seus familiares e controles. Os pacientes usaram estratégias adaptativas com menos frequência do que os familiares (p<0,001) e controles (p=0,003). Não houve diferença significativa entre familiares dos pacientes e controles (p=0,707). Por outro lado, os pacientes (p<0,001) e seus familiares (p=0,004) exibiram pontuações mais elevadas para coping não adaptativo em relação aos controles. Não houve diferença significativa quando os pacientes foram comparados com seus familiares (p=0,517). Conclusões: Familiares de primeiro grau estavam em um nível intermediário entre pacientes com TB e controles no que diz respeito ao uso de habilidades de enfrentamento. Esta descoberta apoia o desenvolvimento de intervenções psicossociais para incentivar o uso de estratégias adaptativas em vez de estratégias inadequadas nessa população.

Abstract Introduction: The objective of this study was to compare patients with bipolar disorder (BD), their first-degree relatives and a group of healthy controls in terms of use of adaptive and maladaptive coping strategies, exploring differences between specific types of strategies and their correlations with clinical variables. Methods: This was a cross-sectional study enrolling 36 euthymic patients with BD, 39 of their first-degree relatives and 44 controls. Coping strategies were assessed using the Brief COPE scale. Results: Significant differences were detected in the use of adaptive and maladaptive strategies by patients, their first-degree relatives and controls. Patients used adaptive strategies less often than the patients’ relatives (p<0.001) and controls (p = 0.003). There was no significant difference between first-degree relatives and controls (p=0.707). In contrast, patients (p<0.001) and their relatives (p=0.004) both exhibited higher scores for maladaptive coping than controls. There was no significant difference regarding the use of maladaptive strategies between patients and their relatives (p=0.517). Conclusions: First-degree relatives were at an intermediate level between patients with BD and controls regarding the use of coping skills. This finding supports the development of psychosocial interventions to encourage use of adaptive strategies rather than maladaptive strategies in this population.

ABSTRACT A total of 5502 piglets from 435 sows were selected for evaluation of the effect of piglet birthweight and sow parity on mortality rate (MR), growth performance, and carcass traits in pigs. Piglets were distributed into one of eight categories according to their weight (<600, 601-800, 801-1000, 1001-1200, 1201-1400, 1401-1600, 1601-1800, and >1801 g) and sows were classified according to parity (1-5). The maximum MR during lactation (day 0 to day 21) was found in category <600 g, whereas the lowest was observed in categories ≥1401 g. Pigs with greater body weight (BW) at birth were equivalently greater until 59 days of age. Average daily weight gain (ADG) was improved by increasing piglet birthweight between 0 and 21 days as indicated by a linear regression effect. After weaning, this effect was reduced up to 168 days, indicated by a quadratic, as opposed to linear, regression effect. The increase in growth rates corresponded to improved lean meat content and hot carcass weight. Increasing sow parity corresponded to a quadratic improvement of BW and ADG during lactation, but not after weaning. However, the improved pre-weaning performance was concomitant with a linear increase of within-litter BW and ADG variation. No effect of parity was observed on carcass traits. Piglet birthweight and sow parity influence litter postnatal development, mainly during early life. After weaning, these effects are less evident with a minor impact on carcass traits.

Resumo Este artigo analisa a reativação da indústria naval no Brasil na década de 2000 como resultado da política neodesenvolvimentista dos governos Lula e Dilma e que repercutiu imediatamente na criação de empregos e postos de trabalho no setor. A partir da contextualização histórica dessa indústria no Brasil, com os dados da Relação Anual de Informações Sociais (Rais), no Cadastro Geral de Empregados e Desempregados (Caged), do Sindicato Patronal (Sinval), bem como de entrevista com o sindicato dos trabalhadores (Stimmmerg) sobre emprego e sua dinâmica de contratação recente, constatamos que, embora essa atividade seja sazonal, caracterizada pela contratação por projetos (encomendas), a crise do emprego no período de 2015 encontra explicação no quadro político e jurídico que se instalou no Brasil.

Abstract This article analyzes the reactivation of the shipbuilding industry in Brazil in the 2000s as a result of the neo-developmentalist policy of the governments of Lula and Dilma, which immediately reflected in the creation of jobs in the sector. Based on the historical contextualization of this industry in Brazil, with the use of data provided by the Annual Social Information List (Rais), by the General Roll of Employed and Unemployed Individuals (Caged), by the employers’ association (SinavaL), and by an interview with the workers’ union (Stimmmerg) on employment and its recent hiring dynamics, we have found that, although this activity is seasonal, characterized by the hiring of workers for specific projects, the employment crisis in 2015 can be explained by the political and legal scenario that has settled in Brazil.

Objetivou-se neste estudo avaliar a inclusão de ractopamina e sua associação com as vitaminas antioxidantes C e E em dietas de suínos em terminação durante 28 dias antes do abate sobre o desempenho, as características de carcaça e a qualidade da carne. Quarenta e oito suínos da linhagem Agroceres PIC (24 machos castrados e 24 fêmeas) foram distribuídos em delineamento experimental de blocos casualizados, em esquema fatorial 3x2, com três dietas: controle; controle + 10ppm de ractopamina; controle + complexo (0,05%) de ractopamina com vitaminas antioxidantes (10ppm de ractopamina + 200mg de vitamina E + 100mg de vitamina C kg-1 de ração) e dois gêneros (machos castrados e fêmeas). Foram avaliados o consumo de ração, o ganho de peso e a conversão alimentar dos animais. Os suínos foram abatidos com peso médio de 100,81±7,81kg. Após o abate, as características de carcaça foram avaliadas e foram coletadas amostras do músculo Longissimus dorsi para a análise da qualidade da carne. Verificou-se diferença (P<0,05) para a conversão alimentar, conformação da carcaça e pH final da carne dos animais que consumiram rações que continham ractopamina. A oxidação da carne foi menor para a dieta com o complexo (ractopamina + vitamina) em relação ao controle (0,10mg kg-1 vs 0,13mg kg-1 TBARS). O marmoreio da carne foi maior (P<0,05) na dieta controle + ractopamina em relação à dieta controle. Os valores de vitamina E no músculo foram mais elevados nos animais que ingeriram as vitaminas antioxidantes (0,23 vs 0,08mg kg-1 vit. E). Conclui-se que a inclusão de ractopamina, associada ou não às vitaminas antioxidantes, promoveu melhora na conversão alimentar e redução da oxidação lipídica da carne

The objective of the study was to evaluate the inclusion of ractopamine and its association with the antioxidant vitamins C and E in finishing pig diets during 28 days prior to slaughter on the performance, carcass traits and meat quality. Forty-eight Agroceres PIC line swine (24 barrows and 24 females) distributed in a randomized blocks factorial design in 3x2 (3 diets: control; control+10ppm of ractopamine; control + complex (0.05%) ractopamine with antioxidant vitamins (10ppm of ractopamine + 200mg of vitamin E+100mg of vitamin C kg-1 of feed) and 2 sex (barrows and females). The feed intake, body weight gain and feed conversion were evaluated. When pigs reached 100.81±7.81kg body weight, they were slaughtered and carcasses were evaluated. Samples of Longissimus dorsi muscle were taken to evaluate the meat quality. Diets with ractopamine improved (P<0.05) feed conversion in pigs, carcass conformation and final pH. The lipid oxidation decreased with the diet (ractopamine+vitamin) in relation to the control diet (0.10mg kg-1 vs 0.13mg kg-1 TBARS). The marbling was higher (P<0.05) in the diet (control + ractopamine) in relation to the control diet. The levels of vitamin E in the muscle were higher in pigs that were fed with antioxidant vitamins (0.23 vs 0.08mg kg-1 vit. E). It was concluded that the inclusion of ractopamine associated or not to antioxidant vitamins improved feed conversion ratio of animals and reduces the lipid oxidation in meat

The objective of this study was to evaluate the consequences of low or high stress during pre-slaughter handling of pigs on their carcass and meat quality. Forty-four animals of a commercial lineage, with an average weight of 107.23±5.23 kg, were used. At lairage the animals were randomly divided into two groups, the least and the most stressed. At slaughter, during bleeding, blood samples were collected for later cortisol and lactate tests. Forty-five minutes after slaughter the initial pH of th carcasses was measured and samples of the semitendinosus muscle were collected for R-value calculation. After 24 hours of cooling, the final pH was measured, damage scores were assessed and samples of the longissimus dorsi muscle were collected to evaluate drip loss, liquid loss from defrosting and cooking, shear force, lipid oxidation, and color. The results were evaluated by analysis of variance and the means were compared by Tukey´s test. It was found that cortisol, lactate and R-value were lower and initial pH was higher for the least stressed animals, whereas the other parameters were not significantly affected. Thus, low stress in the pre-slaughter handling of pigs is effective in reducing stress and carcass damage, but has no effect on meat quality.

The objective was to evaluate the dietary supplementation of different sources of chromium (inorganic: chromium sulfate and chelated: chromium-methionine) during the finishing period of pigs to obtain improvements in the animal performance, and carcass and meat quality. The statistical design was randomized blocks, where 44 barrows, with an initial weight 60.49±5.12 kg, were divided into four blocks (heavier, heavy, light and lighter) according to initial weight. The experimental diets were isoenergetic and isonutrient, except for the chromium level. The treatments were divided as follows: control (without chromium), control + 200 ppb of inorganic chromium (chromium sulfate), and control + 200 ppb of chelated chromium (chromium-methionine). In the performance measures, the stall was considered the experimental unit and in the blood parameters, carcass and meat evaluations each animal constituted the experimental unit. Animals were slaughtered when they reached the final average weight of 107.23±5.23 kg. Blood samples were collected and tested for blood parameters (cholesterol, triglycerides and glucose) as well as carcass quality (hot and cold weights, yield, loin-eye area, muscle depth and backfat thickness) and meat quality (initial and final pH, drip loss, color, chemical composition and lipid oxidation) parameters. Chromium-methionine supplementation provides a greater daily weight gain only compared with the animals that are not supplemented with chromium, because feed conversion is better as compared with the other treatments. After 24 hours of storage, the meat from pigs supplemented either with chromium-methionine or with chromium sulfate presents lower lipid oxidation than that from non-supplemented animals. However, after three days of storage, only chromim-methionine is effective in reducing lipid oxidation.

The objective of this study was to evaluate the performance, the carcass and meat characteristics of ewes supplemented with magnesium oxide. Eighteen 6-year-old Santa Ines ewes were used in a completely randomized experimental design, where three levels of supplementation (0.0, 0.1 and 0.2% magnesium oxide in the concentrate) were tested, with six replicates. Final weight, weight gain, feed intake and feed conversion were not affected by levels of magnesium supplementation. Hot and cold carcass weights showed linear increasing and quadratic responses, respectively, according to supplementation with magnesium. Carcass measurements such as length, depth, and measures of arm and leg were not affected by supplementation. Depth and width of the longissimus muscle and rib-eye area were not affected; however, marbling and ether extract increased linearly with supplementation. Water loss and color were not affected. Lipid oxidation and shear force were not affected by supplementation, while the myofibrillar fragmentation index showed a quadratic regression. There was a linear decrease in pH with magnesium supplementation. Supplementation with magnesium can improve carcass and meat pH, but can act negatively by increasing the amount of marbling and ether extract of meat.

Este trabalho foi desenvolvido com o objetivo de avaliar o desempenho em confinamento de animais puros das raças Tabapuã (T), Bonsmara (B), mestiços ½ Bonsmara + ½ Nelore (B1) e mestiços ½ Bonsmara + ¼ Red Angus + ¼ Nelore (B2). Foram utilizados cinco bovinos castrados de cada grupo genético, com idade média de 22 meses e peso vivo de 394 ± 21 kg, ao início do experimento. A dieta para todos os animais continha silagem de cana-de-açúcar e ração comercial na proporção de 55 e 45% (base seca), respectivamente, com 14,99% de PB e 59,84% de NDT. Os animais foram abatidos quando atingiram escore visual de acabamento de 3, numa escala de 1 = magros a 5 = obesos. Houve efeito significativo dos grupos genéticos sobre o consumo de matéria seca, cujas médias foram de 1,9; 2,1; 2,2 e 2,2% do PV, respectivamente, para os animais Tabapuã, Bonsmara, B1 e B2. O ganho médio diário em peso vivo dos animais cruzados B1 (0,925 kg) e B2 (1,122 kg) e puros Bonsmara (1,035 kg) foi superior ao dos animais da raça Tabapuã (0,630 kg), que foram mais tardios para atingir escore corporal de abate. O consumo de nutrientes, como porcentagem do peso vivo ou por unidade de peso metabólico, não diferiu entre grupos genéticos. Carcaças de animais Bonsmara apresentaram melhor escore de conformação, porém as carcaças dos animais da raça Tabapuã tiveram melhores médias para rendimento de carcaça quente (56,2%) e fria (55,2%). Não houve diferença no peso de carcaça fria entre os grupos genéticos. Animais Bonsmara puros, B1 e B2, apresentam melhor desempenho em confinamento em comparação aos Tabapuã.

The objective of this work was to evaluate feedlot performance of Tabapuã (T) and Bonsmara (B) purebreed animals, and ½ Bonsmara + ½ Nelore (B1) and ½ Bonsmara + ¼ Red Angus + ¼ Nelore (B2) crossbred animals. It was used five castrated bovines from each genetic group at average age of 22 months and live weight of 394 ± 21 kg at the beginning of the experiment. The diet for all the animals contained sugar cane silage and commercial ration at the proportion of 55 and 45% (dry matter basis), respectively, with 14.99% CP and 59.84% TDN. Animals were slaughtered when they reached a visual finishing body score of 3, in a scale from 1 = thin to 5 = obese. There was a significant effect of genetic groups on dry matter intake, whose averages were 1.9, 2.1, 2.2 and 2.2% BW for Tabapuã, Bonsmara, B1 and B2 animals, respectively. Average daily gain in live weight of crossbred animals B1 (0.925 kg) and B2 (1.122 kg) and purebred Bonsmara (1.035 kg) were greater than the ones of Tabapuã (0.630 kg), which were the latest to reach body condition score for slaughtering. Nutrient intake, as percentage of the body weight or per unit of metabolic weight, did not differ among genetic groups. Carcasses of Bonsmara animals presented the best conformation score, but carcasses of Tabapuã animals obtained the best means for hot (56.2%) and for cold (55.2%) dressing percentages. There was no difference for cold carcass weight among the genetic groups. Purebred Bonsmara steers, B1 and B2, presented better fedlot performances in comparison to Tabapuã steers.

Objetivou-se avaliar o desempenho, as características de carcaça e o peso de órgãos do sistema digestório de suínos submetidos a restrição alimentar. Foram utilizados 40 suínos machos castrados, Landrace × Large White, distribuídos em delineamento de blocos casualisados, com quatro tratamentos, cinco repetições e dois animais por parcela experimental. Como tratamentos, avaliaram-se quatro programas de restrição alimentar: um controle, com alimentação à vontade durante os 86 dias de experimento; e outros três, com restrição de 20% no consumo de ração em relação ao grupo controle, durante 21 dias, a partir dos 30, 50 ou 70 kg de peso corporal (PC). Foram mensurados o consumo diário de ração, o ganho diário de peso e a conversão alimentar. As características de carcaça analisadas foram: peso de carcaça quente e fria, comprimento e rendimento de carcaça, espessura de toucinho, profundidade do músculo Longissimus dorsi, rendimento de carne na carcaça, quantidade de carne na carcaça, área de olho-de-lombo e pesos de fígado, estômago e intestinos delgado e grosso. Os custos de cada programa de alimentação foram avaliados para determinação de sua viabilidade. A conversão alimentar, considerando o período total do experimento, foi melhor nos animais mantidos sob restrição a partir dos 70 kg. Os resultados das avaliações de carcaça e dos pesos dos órgãos não diferiram entre os programas de restrição. As análises de custo apontaram melhor relação para a restrição a partir dos 70 kg PC. Em todos os programas de alimentação, a restrição alimentar seguida de alimentação à vontade promoveu ganho compensatório.

The aim of this work was evaluate the animal performance, the carcass characteristics and the weight of the organs of digestive system of pigs submitted to different periods of feed restriction. A total of 40 barrows, Landrace × Large White were distributed to randomized block design, to four feed restriction programs, five replications and two animal per experimental unit. Four restrict programs were evaluated: one control, with ad libitum feeding during the 86 days of experiment, and others three, with restriction of 20% in the feed intake in relation to control group, during 21 days, at 30, 50 or 70 kg BW. Performance characteristics as daily feed intake, daily weight gain and the feed conversion of the animals were evaluated. Carcass characteristics, as hot and cold carcass weights, length and carcass dressing, subcutaneous fat thickness, Longissimus dorsi muscle depth, lean meat yield, lean meat amount and loin eye area were evaluated. Also were evaluated organs weights, as liver, stomach, small and large intestine. The costs of each program were evaluated to observe their viability. Feed conversion, considering total experimental period, was better for the animals kept on feed restriction from 70 kg BW. The carcass characteristics evaluations and organs weights did not differ among feed restriction programs. The costs analysis showed a better relation for feed restriction from 70 kg BW. In all feeding programs, the feed restriction followed by ad libitum feeding promoted a compensatory gain effect for all treatments.

Este trabalho foi realizado com o objetivo de avaliar o efeito da adição de ractopamina na ração sobre a qualidade da carne de suínos dos genótipos halotano homozigoto dominante (HalNN) e heterozigoto (HalNn). Durante o experimento (21 dias), 24 suínos machos castrados e 12 fêmeas (metade de cada genótipo) com peso médio inicial de 72,6 kg de PV foram avaliados segundo delineamento experimental em blocos casualizados, em arranjo fatorial 2 x 2 x 2 (dois genótipos halotano; duas rações: controle e com adição de 10 ppm de ractopamina; e dois sexos: machos castrados e fêmeas). A análise do DNA genômico foi realizada por intermédio das técnicas de PCR-RLPC. A avaliação da qualidade da carne foi realizada no músculo Longissimus dorsi e o pH da carne foi medido 45 minutos (pH inicial) e 24 horas após o abate (pH final). Avaliaram-se a perda de água por gotejamento durante o degelo e a cocção, a cor da carne, o grau de marmoreio e a maciez objetiva. Não houve interação genótipo ´ ractopamina para as características de qualidade da carne avaliadas. Nenhum animal do genótipo homozigoto dominante apresentou carne PSE (textura mole, cor pálida e com pouca água), ao passo que os suínos do genótipo heterozigoto apresentaram carne com 33,3% de PSE. O uso de 10 ppm de ractopamina na ração não afetou os parâmetros de qualidade da carne. Os animais do genótipo HalNn apresentaram carne com qualidade inferior à dos suínos HalNN. O pH final foi menor e a incidência de carne PSE foi maior nos suínos machos castrados que nas fêmeas.

The effect of adding dietary ractopamine on meat quality of dominant homozygote (HalNN) and heterozygote (HalNn) halothane animal genotypes was evaluated in this trial. During the experiment (21days), it was used 24 barrows and 12 gilts (half of each halothane genotype) averaging 72.6 kg initial BW. The experiment was analyzed as a randomized block with a 2 x 2 x 2 factorial arrangement (two halothane genotypes, two diets: control and with 10 ppm of ractopamine and two categories: barrows and gilts). The genomic DNA evaluation was performed by PCR-RLPC. Longissimus dorsi muscle was used for measurement of initial pH (pH45), final pH (pH24) and drip, chilling and cooking losses, meat color, marbleness, and objective softness. No effect of genotype ´ ractopamine interaction on meat characteristic was noticed. Meat of HalNN animals did no show thawing loss and paler (PSE) while that of HalNn had about 33.3% of PSE. Ractopamine did not affect meat quality parameters. Meat of HalNn animals had lower quality than those of HalNN pigs. Meat from barrows presented lower final pH and higher PSE incidence than gilts.

Verificou-se o efeito dos genótipos halotano homozigoto dominante e heterozigoto e dos sistemas de criação confinado sobre piso de cimento, confinado sobre cama de maravalha e ao ar livre sobre a qualidade da carne suína. Foram utilizados 96 suínos machos castrados selecionados através do exame de DNA genômico, utilizando-se a técnica de reação em cadeia de polimerase (PCR) para amplificar a região do receptor rianodina. A região amplificada foi clivada pela técnica polimorfismo do comprimento dos fragmentos de restrição (RFLP). Mediu-se o pH nos músculos Longissimus dorsi e Semimembranosus aos quarenta e cinco minutos e vinte e quatro horas após o abate. A capacidade de retenção de água foi avaliada em amostras do músculo Longissimus dorsi através das técnicas de perda de líquido por gotejamento, de cocção e de descongelamento. Escores para a cor e o grau de marmorização da carne foram atribuídos com auxílio de padrões fotográficos. A maciez da carne foi medida pela força de cisalhamento em equipamento Warner-Bratzler Shear. Suínos com gene halotano heterozigotos apresentaram valores inferiores de pH, menor capacidade de retenção de água e uma freqüência de carcaças com carne PSE três vezes maior. O sistema de criação não afetou os valores de pH inicial e final ou a capacidade de retenção de água da carne suína. A maior incidência de carne PSE foi observada nas carcaças dos suínos criados em sistema confinado sobre piso de concreto. Não houve efeito significativo da interação genótipo halotano e sistema de criação para as características avaliadas.

The effect of halothane genotypes (heterozygous and dominant homozygous) and intensive rearing systems (indoor, wood shavings bedding and outdoor) on pork quality were determinated. Ninety six castrated male pigs were used for the trial. Identification of the halothane genotype was determined in blood samples using the DNA-test, based on the polymerase chain reaction (PCR) amplification of the critical region of the ryanodine receptor and subsequent restricion of the amplifield fragment by the restriction fragment lengh polymorfism (RFLP) technique. The pH at 45 minutes and 24 hours after slaughter was measured on the Longissimus dorsi and Semimembranosus muscles. At the laboratory, the Longissimus dorsi muscle was used for the evaluation of the color, marbling, drip loss, defrosting loss and cooking loss and shear force. The muscle of heterozygous pigs for the halothane gene had lower pH and higher drip loss and the incidence of the PSE condition in this genotype was three times higher. The rearing system did not affect the initial and ultimate pH or water holding capacity. Indoor reared pigs had greater frequency of PSE carcass. The interaction between halothane genotypes and rearing systems had no significant effect on any trait studied.