No description available.

AMP-activated protein kinase (AMPK) is a major regulator of skeletal muscle metabolism with relevance to agriculture and human health. During the conversion of muscle to meat, the rate and extent of postmortem metabolism and pH decline largely determine pork quality development. Pigs with the AMPKγ3 R200Q mutation generate pork with low ultimate pH (pHu); this is attributed to high glycogen content, and greater "potential" to produce lactate and H+. We hypothesized that decreasing muscle phosphocreatine and creatine would decrease ATP buffering capacity, resulting in earlier termination of glycolysis and pH decline. Dietary supplementation with the creatine analogue, β-GPA, decreased muscle total creatine but negatively affected performance. Another experiment was conducted using control or β-GPA diet and wild type and AMPKγ3R200Q pigs in a 2Ã 2 factorial design. The loss of muscle total creatine was important in maintenance of ATP levels in AMPKγ3R200Q muscle early postmortem. Moreover, elevated glycogen did not affect pHu, supporting that energetic modifications induced by feed restriction and β-GPA supplementation influence extent of pH decline. Next, we utilized a line of pigs selected for differences in pHu. Another AMPKγ3 mutation (V199I), which is associated with higher pHu and lower glycolytic potential, was prevalent. The 199II genotype increased pHu in castrated males only. The wild type VV genotype increased glycolytic potential, but neither glycolytic potential nor lactate predicted pHu. In humans, AMPK activation is at least partly responsible for the beneficial effects of exercise on glucose transport and increased oxidative capacity in skeletal muscle. An inverse relationship exists between skeletal muscle fiber cross-sectional area and oxidative capacity, which suggests muscle fibers hypertrophy at the expense of oxidative capacity. Therefore, we utilized pigs possessing mutations associated with increased oxidative capacity (AMP-activated protein kinase, AMPKγ3R200Q) or fiber hypertrophy (ryanodine receptor 1, RyR1R615C) to determine if these events occur in parallel. RyR1R615C increased muscle fiber size; AMPKγ3R200Q increased oxidative capacity, evidenced by enhanced enzyme activity, mitochondrial function, and expression of mitochondrial proteins. Thus, pigs with both AMPKγ3R200Q and RyR1R615C possess increased fiber size and oxidative capacity, suggesting hypertrophy and oxidative capacity can occur simultaneously in skeletal muscle. / Ph. D.

Two trials (n = 160) were conducted to evaluate the effects of the halothane gene, chromium picolinate supplementation, and sex on growth performance, carcass characteristics, and meat quality in pigs. Halothane negative (NN) and halothane carrier (Nn) pigs (barrows, gilts) were supplemented with either 0 or 200 ppb chromium picolinate from 28.7 to 107.3 kg. There were no differences between genotypes for ADG or G/F. Chromium had no significant effect on any growth, carcass, or muscle quality characteristics, although chromium-fed pigs were slightly fatter. Barrows gained faster (P < .001) and consumed more feed (P < .001) than gilts, yielding heavier (P < .001) carcasses, and heavier (P < .05) wholesale cuts. Gilts had less backfat (P < .001) and larger (P < .01) LMA, and tended to gain more efficiently than barrows. Carrier pigs had lower pH values, higher CIE L* values, higher drip loss, and lower protein solubility (P < .05), all indicators of decreased quality. Chromium supplementation resulted in pork with higher (P<.05) CIE a*, CIE b*, and Chroma C values. Halothane carrier barrows and all gilts that were not fed chromium had lower lipid muscle content than NN barrows (P < .05). Gilts had higher CIE L* and a* values (P < .001), less lipid, and higher moisture percentage (P < .02) than barrows. Chromium picolinate did not negatively affect pork muscle quality. / Master of Science

Call number: LD2668 .T4 1985 C525 / Master of Science

The development of a reduced energy Thai style fresh pork sausage has been achieved by replacing fat with carbohydrate and water. Replacing fat in the processed meat formulation with other ingredients is known to alter the product qualities. The addition of carbohydrate, namely mung bean vermicelli, as a fat replacement is suggested to improve the water holding capacity, cooking yield and textural properties as well as reduce the fat and total energy content. This research developed a standard processing methodology for a characteristic Thai fresh pork sausage. The research evaluated the potential of mung bean vermicelli in the formulation of a reduced energy Thai style fresh pork sausage. The reduced energy sausage was developed by replacing fat with 25%, 50%, 75%, and 100% soaked mung bean vermicelli. Quality characteristics of the sausages (chemical, textural and sensory) were evaluated and compared with control sausages (20% fat). The results of the present study indicated that soaked mung bean vermicelli offset many of the characteristic changes usually brought about by fat reduction. The sausages had a decreased cooking loss and an improved yield as well as a reduction in energy content. In addition, they maintained the textural and sensory characteristics of the control Thai style fresh pork sausages. / Master of Science (Hons)

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 349-369). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 349-369). Also available on the Internet.

O isolamento de Salmonella enterica em suínos abatidos tem sido reportado no sul do Brasil, o que torna a carne suína uma fonte potencial de contaminação para os consumidores. Nesse contexto, o trabalho propôs estimar o risco da ocorrência de infecção alimentar pelo consumo de lingüiça frescal suína, através da análise de dados de prevalência, quantificação, cinética de crescimento e destruição e de surtos alimentares que envolveram Salmonella no Rio Grande do Sul. Das 336 amostras de lingüiça frescal de carne suína adquiridas no comércio, 24,4% apresentaram Salmonella sp. com contagens variando entre 0,03 e 460 Número mais Provável (NMP).g-1, com mediana de 0,23 NMP.g-1. Os sorovares mais prevalentes foram Brandenburg, Derby, Panama e Typhimurium. Em simulações de crescimento e destruição realizadas em caldo nutriente, isolados dos 12 sorovares encontrados no produto, apresentaram cinética de crescimento semelhante em temperatura ambiente. Até duas horas todos os sorotipos permaneceram em fase lag e, após, iniciou-se a fase exponencial. Em temperatura de refrigeração, todos os isolados mantiveram a contagem inicial até 30 dias. A destruição térmica em 60°C ocorreu após 20 minutos em todos os ensaios. As mesmas simulações foram conduzidas em amostras do produto contaminadas artificialmente com Salmonella sp. não havendo alterações significativas nas quantidades de Salmonella em temperatura ambiente e de refrigeração durante todo o período de observação. Após a preparação em forno (200°C), por 15 minutos, a população total inoculada foi destruída. Nos surtos ocorridos por Salmonella, os alimentos a base de ovos, maionese e frango predominaram. Os resultados obtidos na quantificação variaram de <3 NMP até 4,6x109.g-1desses alimentos, com mediana de 4,6x106.g-1. S. Enteritidis foi o sorovar identificado em todos os surtos, apresentando um único perfil de macro-restrição. Os dados obtidos foram utilizados para simular diferentes cenários no programa @Risk. Considerando-se o costume da população estudada de ingerir este produto após tratamento térmico, o risco encontrado foi muito baixo (6,12 x 10-7). Para uma pequena parte da população que costuma ingerir o produto sem qualquer tratamento térmico, em uma simulação realizada com 10.000 refeições, poderá haver 8,78 casos da doença, considerando a ingestão de uma única unidade. Em um perfil típico de preparação e consumo de lingüiça frescal de carne suína pela população de Porto Alegre, ou seja, como acompanhamento de churrasco, após tratamento térmico mínimo de 15 minutos, calculou-se a probabilidade de ocorrência de doença.Dentre os 3.354.716,98 churrascos estimados consumidos mensalmente em Porto Alegre, o resultado do modelo indicou um mínimo de 0,01, média de 2,05 e máximo de 11,08 casos de doença por mês. Esse cenário infere que a lingüiça frescal de carne suína pode estar causando um baixo número de casos isolados em Porto Alegre, os quais podem estar sendo subnotificados. / In Southern Brazil, a high prevalence of Salmonella isolation has been reported in slaughter pigs, indicating that pork may represent a hazard to the consumers. In this sense, this study aimed to conduct a risk analysis of the consumption of pork sausage in Southern Brazil. For this purpose, Salmonella prevalence on pork sausages collected at retail level was estimated, growth and death curves for representative porcine Salmonella strains were constructed, the consumption patterns of pork sausages by the population were investigated, and foods involved in salmonellosis outbreaks were analysed. From a total of 336 samples of fresh pork sausage examined, Salmonella enterica was detected in 82 (24.4%) of the samples, with a Most Probable Number count ranging from 0.03 (MPN).g-1 to 460 MPN.g-1, and a median of 0.23 MPN .g-1. Strains belonging to serovars Brandenburg, Panama, Derby and Typhimurium were the most prevalent. Growth and death curves of 12 strains representing Salmonella serovars isolated in this study were similar in assays conducted in nutrient broth. At room temperature, all Salmonella serovars started the exponential phase after a two hours period of lag phase. Under refrigeration, all isolates mantained the initial population counts up to 30 days. The heat destruction was observed after 20 minutes in all assays. Similar assays conducted in fresh pork sausages inoculated with Salmonella demonstrated that no growth of Salmonella sp. could be detected at room temperature and under refrigeration troughout the observation period. After cooking in the oven (200°C) for 15 minutes the inoculated Salmonella population was completely destroyed. Foods containing eggs, mayonnaise or chicken were the most implicated in outbreaks investigated in Rio Grande do Sul. Salmonella counts variaded from <3 MPN to 4.6x109.g-1 of foods involved in these outbreaks, with a median value of 4.6x106.g-1. All strains were identified as S. Enteritidis, and presented a unique macrorestriction profile, demonstrating the predominance of one clonal group in foods involved in the salmonellosis outbreaks. Data obtained in the conducted assays were used to simulate different cenarios, using the @Risk software. Considering that the population usually consums pork sausage after termic treatment (roasting), the estimated risk was very low (6.12 x 10-7). Another simulation, conducted for the low percentage of the population (3%) that declared to consum raw pork sausage, indicated that for 10,000 meal consumption events of one sausage, the probability is 8.78 disease cases. Finally, considering the typical consumption pattern of pork sausage by the population of Porto Alegre city (roasted for at least 15 minutes during a barbecue called “churrasco”) the number of disease cases was simulated. Among 3,354,716.98 “churrascos” prepared monthly in Porto Alegre city, the model indicated a probability of a minimum of 0.01 cases, a media of 2.05 and a maximum of 11.08 disease cases occurring each month. Results of risk assessment show that fresh pork sausage may have been a cause of few undernotificated individual salmonellosis cases in Porto Alegre city.

The work deals with economic evaluation of pork production in agricultural cooperative Opařany (ACO) in the period 2007-2010. The research reviewed both economic indicators and indicators of production and reproduction. Nutrition and feeding of pigs was also assessed from the perspective: influence on production and reproduction and share of cost breeding pigs. Evaluation of indicators is not only in time but also in the space, where average values of Czech breeders were used. ACO in 2008 experience worsening of breeding indicators and also increasing costs of one feeding day. It led to a loss 10,11 CZK per 1kg of live weight of slaughter pig. Since 2008 the ACO has been gradually improving. In 2010, there were weaned 23 piglets per 1 sow per a year. In fattening reached 0,68 daily gain. In indicators of reproduction is ACO above Czech average. ACO was also successful in gradual reduction of total cost. In 2010, ACO produced 1 kg of live weight of slaughter pig per 33,25 CZK. Despite the mentioned improvement, the ACO -production of pork was loss during the whole follow-up period. In 2010, the loss on every sold kilo of slaughter pig was 5,36 CZK.

O isolamento de Salmonella enterica em suínos abatidos tem sido reportado no sul do Brasil, o que torna a carne suína uma fonte potencial de contaminação para os consumidores. Nesse contexto, o trabalho propôs estimar o risco da ocorrência de infecção alimentar pelo consumo de lingüiça frescal suína, através da análise de dados de prevalência, quantificação, cinética de crescimento e destruição e de surtos alimentares que envolveram Salmonella no Rio Grande do Sul. Das 336 amostras de lingüiça frescal de carne suína adquiridas no comércio, 24,4% apresentaram Salmonella sp. com contagens variando entre 0,03 e 460 Número mais Provável (NMP).g-1, com mediana de 0,23 NMP.g-1. Os sorovares mais prevalentes foram Brandenburg, Derby, Panama e Typhimurium. Em simulações de crescimento e destruição realizadas em caldo nutriente, isolados dos 12 sorovares encontrados no produto, apresentaram cinética de crescimento semelhante em temperatura ambiente. Até duas horas todos os sorotipos permaneceram em fase lag e, após, iniciou-se a fase exponencial. Em temperatura de refrigeração, todos os isolados mantiveram a contagem inicial até 30 dias. A destruição térmica em 60°C ocorreu após 20 minutos em todos os ensaios. As mesmas simulações foram conduzidas em amostras do produto contaminadas artificialmente com Salmonella sp. não havendo alterações significativas nas quantidades de Salmonella em temperatura ambiente e de refrigeração durante todo o período de observação. Após a preparação em forno (200°C), por 15 minutos, a população total inoculada foi destruída. Nos surtos ocorridos por Salmonella, os alimentos a base de ovos, maionese e frango predominaram. Os resultados obtidos na quantificação variaram de <3 NMP até 4,6x109.g-1desses alimentos, com mediana de 4,6x106.g-1. S. Enteritidis foi o sorovar identificado em todos os surtos, apresentando um único perfil de macro-restrição. Os dados obtidos foram utilizados para simular diferentes cenários no programa @Risk. Considerando-se o costume da população estudada de ingerir este produto após tratamento térmico, o risco encontrado foi muito baixo (6,12 x 10-7). Para uma pequena parte da população que costuma ingerir o produto sem qualquer tratamento térmico, em uma simulação realizada com 10.000 refeições, poderá haver 8,78 casos da doença, considerando a ingestão de uma única unidade. Em um perfil típico de preparação e consumo de lingüiça frescal de carne suína pela população de Porto Alegre, ou seja, como acompanhamento de churrasco, após tratamento térmico mínimo de 15 minutos, calculou-se a probabilidade de ocorrência de doença.Dentre os 3.354.716,98 churrascos estimados consumidos mensalmente em Porto Alegre, o resultado do modelo indicou um mínimo de 0,01, média de 2,05 e máximo de 11,08 casos de doença por mês. Esse cenário infere que a lingüiça frescal de carne suína pode estar causando um baixo número de casos isolados em Porto Alegre, os quais podem estar sendo subnotificados. / In Southern Brazil, a high prevalence of Salmonella isolation has been reported in slaughter pigs, indicating that pork may represent a hazard to the consumers. In this sense, this study aimed to conduct a risk analysis of the consumption of pork sausage in Southern Brazil. For this purpose, Salmonella prevalence on pork sausages collected at retail level was estimated, growth and death curves for representative porcine Salmonella strains were constructed, the consumption patterns of pork sausages by the population were investigated, and foods involved in salmonellosis outbreaks were analysed. From a total of 336 samples of fresh pork sausage examined, Salmonella enterica was detected in 82 (24.4%) of the samples, with a Most Probable Number count ranging from 0.03 (MPN).g-1 to 460 MPN.g-1, and a median of 0.23 MPN .g-1. Strains belonging to serovars Brandenburg, Panama, Derby and Typhimurium were the most prevalent. Growth and death curves of 12 strains representing Salmonella serovars isolated in this study were similar in assays conducted in nutrient broth. At room temperature, all Salmonella serovars started the exponential phase after a two hours period of lag phase. Under refrigeration, all isolates mantained the initial population counts up to 30 days. The heat destruction was observed after 20 minutes in all assays. Similar assays conducted in fresh pork sausages inoculated with Salmonella demonstrated that no growth of Salmonella sp. could be detected at room temperature and under refrigeration troughout the observation period. After cooking in the oven (200°C) for 15 minutes the inoculated Salmonella population was completely destroyed. Foods containing eggs, mayonnaise or chicken were the most implicated in outbreaks investigated in Rio Grande do Sul. Salmonella counts variaded from <3 MPN to 4.6x109.g-1 of foods involved in these outbreaks, with a median value of 4.6x106.g-1. All strains were identified as S. Enteritidis, and presented a unique macrorestriction profile, demonstrating the predominance of one clonal group in foods involved in the salmonellosis outbreaks. Data obtained in the conducted assays were used to simulate different cenarios, using the @Risk software. Considering that the population usually consums pork sausage after termic treatment (roasting), the estimated risk was very low (6.12 x 10-7). Another simulation, conducted for the low percentage of the population (3%) that declared to consum raw pork sausage, indicated that for 10,000 meal consumption events of one sausage, the probability is 8.78 disease cases. Finally, considering the typical consumption pattern of pork sausage by the population of Porto Alegre city (roasted for at least 15 minutes during a barbecue called “churrasco”) the number of disease cases was simulated. Among 3,354,716.98 “churrascos” prepared monthly in Porto Alegre city, the model indicated a probability of a minimum of 0.01 cases, a media of 2.05 and a maximum of 11.08 disease cases occurring each month. Results of risk assessment show that fresh pork sausage may have been a cause of few undernotificated individual salmonellosis cases in Porto Alegre city.