RESUMEN

Analisaram-se os efeitos da energia metabolizável (EM) e da idade de abate sobre o desempenho zootécnico, o rendimento de carcaça e de partes de frangos da linhagem Caipira Francês Exótico. Foram utilizadas 192 aves, distribuídas em delineamento inteiramente ao acaso, com três tratamentos e quatro repetições de 16 aves cada. Os tratamentos (T) foram definidos de acordo com os níveis de energia das dietas inicial (1 a 28 dias) e final (29 a 90 dias), respectivamente, em: T1 - 3.000 e 3.100kcal de EM/kg; T2 - 3.100 e 3.200kcal de EM/kg; T3 - 3.200 e 3.300kcal de EM/kg. Os abates foram realizados aos 77, 84 e 90 dias. Na fase inicial, as aves do T2 e do T3 apresentaram maior peso médio (655,75 e 713,50g), maior ganho de peso (24,28 e 26,42g/ave) e melhor conversão alimentar (1,59 e 1,77), e não diferiram entre si (P>0,05). Quando abatidas aos 77 dias de idade, as aves que consumiram a dieta com 3.100/3.200kcal de EM/kg apresentaram maior rendimento de carcaça (82,20%) e de peito (24,26%), e não diferiram dos frangos alimentados com dietas contendo 3.000/3.200kcal de EM/kg, nos quais se verificaram rendimento de carcaça de 80,72% e 23,20% de rendimento de peito. Os frangos da linhagem Caipira Francês Exótico apresentaram melhores desempenho zootécnico e rendimento de carcaça quando alimentados com dietas contendo 3.100 a 3.200kcal de EM/kg na ração e abatidos aos 77 dias de idade.

This is study aimed to analyze the effects of metabolizable energy (ME) and age at slaughter on growth performance, carcass yield and prime cuts, relative weight of the wings, back, head + neck and feet of broiler chickens from the Caipira Francês Exótico strain. A total of 192 birds were distributed in a completely randomized design with three treatments and four replicates of 16 birds per treatment. The treatments were defined according to levels of dietary energy (1 to 28 days) and late (29-90 days), respectively: T1 - 3000 and 3100kcal/kg ME, T2 - 3100 and 3200kcal/kg ME, T3 - 3200 and 3300kcal/kg ME. The slaughter was carried out at 77, 84 and 90 days. In the initial phase the birds from T2 and T3 had a higher mean weight (655.75 and 713.50g), weight gain (24.28 and 26.42g/bird) and better feed gain (1.59 and 1.77) and did not differ (P>0.05). When slaughtered at 77 days of age, birds fed the diet with 3.100/3.200kcal/kg ME had higher carcass yield (82.20%) and breast (24.26%), and did not differ from chickens fed diets containing 3.000/3.200kcal/kg ME, where a carcass yield of 80.72% and 23.20% of breast yield was found. The Caipira Francês Exótico broilers had better growth performance and carcass yield than when fed diets containing 3100-3200kcal/kg in the diet and slaughtered at 77 days old.

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The effects of cashew nut shell liquid (CNSL) on growth performance, carcass yield, relative weight of internal organs and microbiology of digestive tract of broiler chickens were investigated. Five hundred and forty male broiler chicks at one day of age were arranged in a completely randomized design with six treatments and six repetitions with 15 broiler chicks each. The treatments were: control (T1 - without growth promoter virginiamycin and CNSL); inclusion levels of 0.10mL (T2), 0.20mL (T3), 0.30mL (T4) and 0.40mL (T5) of CNSL/kg of feed; and commercial promoter virginiamycin (T6). At 21 and 40 days of age, body weight, feed intake, feed conversion and viability of birds were similar in all treatments. Carcass yield was higher in the treatment with the growth promoter when compared to the control treatment. There was a linear increase in carcass yield when the level of CNSL was increased in the diet. The relative weight of the intestine was lower in the treatment containing virginiamycin when compared to the treatment without the inclusion of additives. The relative weight of the intestines decreased when the levels of inclusion of CNSL were increased. There was a gradual reduction of Escherichia coli concentration reaching the lowest number on the CNSL level of 0.30mL/kg. It was concluded that CNSL showed similar performance and slaughter yield as the growth promoter and reduced the concentration of Escherichia coli in the intestinal contents.

Um estudo foi conduzido para investigar os efeitos do líquido da casca da castanha de caju (LCC) sobre o desempenho, o rendimento de carcaça, o peso relativo dos órgãos internos e a microbiologia do trato digestivo de frangos de corte. Foram utilizados 540 pintos machos de um dia de idade, distribuídos num delineamento inteiramente casualizado, com seis tratamentos e seis repetições de 15 aves cada. Os tratamentos consistiram em: controle (T1 - sem promotor comercial e sem LCC), níveis de inclusão de 0,10mL (T2), 0,20mL (T3), 0,30mL (T4) e 0,40mL (T5) de LCC/kg de ração e T6 (promotor comercial - virginiamicina). Aos 21 e 40 dias de idade, o peso corporal, o consumo de ração, a conversão alimentar e a viabilidade das aves foram semelhantes em todos os tratamentos. O rendimento de carcaça foi superior no tratamento com promotor de crescimento em relação ao tratamento-controle. Ocorreu uma resposta linear de incremento no rendimento de carcaça com o aumento do nível de LCC na dieta. O peso relativo dos intestinos foi menor no tratamento com virginiamicina em relação ao tratamento-controle. O peso relativo dos intestinos diminuiu com o aumento do nível de inclusão do LCC. Houve uma redução gradual da concentração de Escherichia coli, cuja menor concentração atingiu o nível de 0,30mL/kg. Conclui-se que o LCC mostrou desempenho e rendimento de abate semelhantes ao promotor de crescimento e reduziu a concentração de Escherichia Coli no conteúdo intestinal.

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RESUMEN

Analisaram-se os efeitos da energia metabolizável (EM) e da idade de abate sobre o desempenho zootécnico, o rendimento de carcaça e de partes de frangos da linhagem Caipira Francês Exótico. Foram utilizadas 192 aves, distribuídas em delineamento inteiramente ao acaso, com três tratamentos e quatro repetições de 16 aves cada. Os tratamentos (T) foram definidos de acordo com os níveis de energia das dietas inicial (1 a 28 dias) e final (29 a 90 dias), respectivamente, em: T1 - 3.000 e 3.100kcal de EM/kg; T2 - 3.100 e 3.200kcal de EM/kg; T3 - 3.200 e 3.300kcal de EM/kg. Os abates foram realizados aos 77, 84 e 90 dias. Na fase inicial, as aves do T2 e do T3 apresentaram maior peso médio (655,75 e 713,50g), maior ganho de peso (24,28 e 26,42g/ave) e melhor conversão alimentar (1,59 e 1,77), e não diferiram entre si (P>0,05). Quando abatidas aos 77 dias de idade, as aves que consumiram a dieta com 3.100/3.200kcal de EM/kg apresentaram maior rendimento de carcaça (82,20%) e de peito (24,26%), e não diferiram dos frangos alimentados com dietas contendo 3.000/3.200kcal de EM/kg, nos quais se verificaram rendimento de carcaça de 80,72% e 23,20% de rendimento de peito. Os frangos da linhagem Caipira Francês Exótico apresentaram melhores desempenho zootécnico e rendimento de carcaça quando alimentados com dietas contendo 3.100 a 3.200kcal de EM/kg na ração e abatidos aos 77 dias de idade.(AU)

This is study aimed to analyze the effects of metabolizable energy (ME) and age at slaughter on growth performance, carcass yield and prime cuts, relative weight of the wings, back, head + neck and feet of broiler chickens from the Caipira Francês Exótico strain. A total of 192 birds were distributed in a completely randomized design with three treatments and four replicates of 16 birds per treatment. The treatments were defined according to levels of dietary energy (1 to 28 days) and late (29-90 days), respectively: T1 - 3000 and 3100kcal/kg ME, T2 - 3100 and 3200kcal/kg ME, T3 - 3200 and 3300kcal/kg ME. The slaughter was carried out at 77, 84 and 90 days. In the initial phase the birds from T2 and T3 had a higher mean weight (655.75 and 713.50g), weight gain (24.28 and 26.42g/bird) and better feed gain (1.59 and 1.77) and did not differ (P>0.05). When slaughtered at 77 days of age, birds fed the diet with 3.100/3.200kcal/kg ME had higher carcass yield (82.20%) and breast (24.26%), and did not differ from chickens fed diets containing 3.000/3.200kcal/kg ME, where a carcass yield of 80.72% and 23.20% of breast yield was found. The Caipira Francês Exótico broilers had better growth performance and carcass yield than when fed diets containing 3100-3200kcal/kg in the diet and slaughtered at 77 days old.(AU)

Asunto(s)

RESUMEN

The effects of cashew nut shell liquid (CNSL) on growth performance, carcass yield, relative weight of internal organs and microbiology of digestive tract of broiler chickens were investigated. Five hundred and forty male broiler chicks at one day of age were arranged in a completely randomized design with six treatments and six repetitions with 15 broiler chicks each. The treatments were: control (T1 - without growth promoter virginiamycin and CNSL); inclusion levels of 0.10mL (T2), 0.20mL (T3), 0.30mL (T4) and 0.40mL (T5) of CNSL/kg of feed; and commercial promoter virginiamycin (T6). At 21 and 40 days of age, body weight, feed intake, feed conversion and viability of birds were similar in all treatments. Carcass yield was higher in the treatment with the growth promoter when compared to the control treatment. There was a linear increase in carcass yield when the level of CNSL was increased in the diet. The relative weight of the intestine was lower in the treatment containing virginiamycin when compared to the treatment without the inclusion of additives. The relative weight of the intestines decreased when the levels of inclusion of CNSL were increased. There was a gradual reduction of Escherichia coli concentration reaching the lowest number on the CNSL level of 0.30mL/kg. It was concluded that CNSL showed similar performance and slaughter yield as the growth promoter and reduced the concentration of Escherichia coli in the intestinal contents.(AU)

Um estudo foi conduzido para investigar os efeitos do líquido da casca da castanha de caju (LCC) sobre o desempenho, o rendimento de carcaça, o peso relativo dos órgãos internos e a microbiologia do trato digestivo de frangos de corte. Foram utilizados 540 pintos machos de um dia de idade, distribuídos num delineamento inteiramente casualizado, com seis tratamentos e seis repetições de 15 aves cada. Os tratamentos consistiram em: controle (T1 - sem promotor comercial e sem LCC), níveis de inclusão de 0,10mL (T2), 0,20mL (T3), 0,30mL (T4) e 0,40mL (T5) de LCC/kg de ração e T6 (promotor comercial - virginiamicina). Aos 21 e 40 dias de idade, o peso corporal, o consumo de ração, a conversão alimentar e a viabilidade das aves foram semelhantes em todos os tratamentos. O rendimento de carcaça foi superior no tratamento com promotor de crescimento em relação ao tratamento-controle. Ocorreu uma resposta linear de incremento no rendimento de carcaça com o aumento do nível de LCC na dieta. O peso relativo dos intestinos foi menor no tratamento com virginiamicina em relação ao tratamento-controle. O peso relativo dos intestinos diminuiu com o aumento do nível de inclusão do LCC. Houve uma redução gradual da concentração de Escherichia coli, cuja menor concentração atingiu o nível de 0,30mL/kg. Conclui-se que o LCC mostrou desempenho e rendimento de abate semelhantes ao promotor de crescimento e reduziu a concentração de Escherichia Coli no conteúdo intestinal.(AU)

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The elevated expression of stress proteins is considered to be a universal response to adverse conditions, representing a potential mechanism of cellular defense against disease and a potential target for novel therapeutics. Exposure to arsenicals either in vitro or in vivo in a variety of model systems has been shown to cause the induction of a number of the major stress protein families such as heat shock proteins (Hsp). Among them are members with low molecular weight, such as metallotionein and ubiquitin, as well as ones with masses of 27, 32, 60, 70, 90, and 110 kDa. In most of the cases, the induction of stress proteins depends on the capacity of the arsenical to reach the target, its valence, and the type of exposure, arsenite being the biggest inducer of most Hsp in several organs and systems. Hsp induction is a rapid dose-dependent response (1-8 h) to the acute exposure to arsenite. Thus, the stress response appears to be useful to monitor the sublethal toxicity resulting from a single exposure to arsenite. The present paper offers a critical review of the capacity of arsenicals to modulate the expression and/or accumulation of stress proteins. The physiological consequences of the arsenic-induced stress and its usefulness in monitoring effects resulting from arsenic exposure in humans and other organisms are discussed.

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The role of cytochrome P450 (CYP) and the CYP isoform involved in the activation of the widely used pesticide methyl-parathion (MePA) were investigated in rat brain extracts by measuring the effect of different CYP inhibitors on acetylcholinesterase (AChE) inhibition by MePA. Brain extracts provide a useful tool to study the activation mechanisms of organophosphorus compounds (OP) since they contain both the activating enzyme(s) and the molecular target for OP toxicity. As expected, in incubations of rat brain extract supplemented with NADPH, AChE activity was non-competitively inhibited by the presence of MePA, indicating that MePA was activated to its reactive metabolite methyl-paraoxon (MePO). Indeed, Vmax(app) decreased from 13.4 to 8.7 micromol thionitrobenzoic acid (TNB)/min per mg protein. MePA activation by rat brain extracts, as measured by the AChE inhibition produced by the presence of the pesticide in the incubation, was fully prevented by previously bubbling the incubation mix with CO, by the presence of monoclonal anti-rat CYP2B1/2B2 antibodies and by the addition of phenobarbital (PB), a CYP2B substrate. Interestingly, MePA showed a greater affinity for CYP2B than PB. CYP1A1 antibodies showed no effect on MePA activation. The presence of cytochrome P450 2B (CYP2B) in the rat brain extracts was confirmed by immunoblotting. These results demonstrate indisputably the responsibility of CYP2B in MePA activation in the rat brain in vitro, suggesting that metabolic activation of OP compounds in situ might be crucial for their organ specific toxicity to the central nervous system also in vivo.

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Industrial development has resulted in an increased release of chemicals and other agents into the environment, resulting in damage to the environment as well as increasing the risk of adverse effects on human health. Environmental toxicology (ET) is the discipline responsible for assessing the risks to human health and the environment from the effects of new chemicals and those already present in the environment. The development of human resources in toxicology is therefore a priority in both Latin America (LA) and the European Union (EU), although LA professionals are more involved in risk evaluation than in risk assessment compared to their EU colleagues. A solid background in general toxicology will enable those interested in environmental issues to tackle local problems. Moreover, the increasing globalization of markets and, therefore, of the necessary regulations, requires harmonisation of postgraduate programmes to ensure that risk assessment and management related to the environment are dealt with uniformly and by highly qualified scientists. The Inaugural Meeting of the ALFA-OMET Toxicology', a 2-year programme supported by the European Commission, offered the opportunity to discuss a number of these issues. The present status of existing ET courses in the EU and LA and the corresponding professional profiles in the two regions were examined, and a harmonized academic curriculum for a postgraduate professional profiles in the two regions were examined, and a harmonized academic curriculum for a postgraduate course in environmental toxicology was developed. Finally, a course programme for toxicology and a specialization in environmental toxicology designed by a panel of experts was discussed, and its relevance as a model for other specialisation programmes was analysed. Exercises such as those performed by ALFA-OMET may be useful not only in promoting discussion for the implementation of national and international professional registers in LA, but also in encouraging the same, ongoing process in the EU.

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