RESUMO
This study aimed to evaluate the effect of heat stress (HS) and selenium supplementation on markers of stress, meat quality and gene expression. For this, meat quails of 42 days of age were fed a diet that either met [0.33 mg/kg, nutritional demand for selenium (SS)] or did not meet [0.11 mg/kg, selenium deficient (SD)] the nutritional demands for selenium during the 7 days of evaluation. In addition, the animals were kept at either a thermal comfort temperature (25 °C) or exposed to HS (38 °C for 24 h). Glutathione synthetase (GSS), glutathione reductase (GSR) and uncoupling protein (UCP) gene expression were influenced by the interaction between temperature and diet. Animals subjected to HS and fed the SS diet exhibited the highest GSS and GSR gene expression. In terms of UCP gene expression, the lowest values were observed in HS animals on the SD diet. Glutathione peroxidase 7 (GPX7) gene expression, body temperature (BT) and creatine kinase (CK) activity were influenced by both selenium supplementation and HS. Aspartate aminotransferase (AST), alanine aminotransferase (ALT) activity and creatinine content all were influenced by the diet/environment interaction. The highest AST activity, ALT activity and creatinine levels were observed in animals that were both on the SD diet and exposed to HS. HS animals also exhibited an increased heterophil/lymphocyte ratio and lower triiodothyronine (T3) hormone levels than birds that remained at the comfortable temperature. Animals subjected to HS and fed with selenium supplemented diet showed better results regarding gene expression and, thus, better results for the activities of enzymes used as stress markers, which could be due to the higher antioxidant capacity provided by the action of the studied genes.
Assuntos
Coturnix , Transtornos de Estresse por Calor/veterinária , Estresse Oxidativo/efeitos dos fármacos , Doenças das Aves Domésticas , Selênio/farmacologia , Ração Animal/análise , Animais , Biomarcadores/sangue , Dieta/veterinária , Suplementos Nutricionais , Regulação da Expressão Gênica , Transtornos de Estresse por Calor/dietoterapia , Carne/normasRESUMO
The aim of the present study was to evaluate the effects of heat stress (HS) and methionine supplementation on the markers of stress and on the gene expression levels of uncoupling proteins (UCP), betaine-homocysteine methyltransferase (BHMT), cystathionine ß-synthase (CBS), glutathione synthetase (GSS) and glutathione peroxidase 7 (GPx7). Broilers from 1 to 21 d and from 22 to 42 d of age were divided into three treatment groups related to methionine supplementation: without methionine supplementation (MD); recommended level of methionine supplementation (DL1); excess methionine supplementation (DL2). The broilers were either kept at a comfortable thermal temperature or exposed to HS (38°C for 24 h). During the starter period, we observed the effects of the interaction between diet and environment on the gene expression levels of UCP, BHMT and GSS. Higher gene expression levels of UCP and BHMT were observed in broilers that were maintained at thermal comfort conditions and received the MD diet. HS broilers fed the DL1 and DL2 diets had the highest expression level of GSS. The expression levels of the CBS and GPx7 genes were influenced by both the environment and methionine supplementation. During the grower period, the gene expression levels of BHMT, CBS, GSS and GPx7 were affected by the diet × environment interaction. A higher expression level of BHMT was observed in broilers maintained at thermal comfort conditions and on the MD diet. HS induced higher expression levels of CBS, GSS and GPx7 in broilers that received the DL1 and DL2 diets. The present results suggest that under HS conditions, methionine supplementation could mitigate the effects of stress, since methionine contributed to the increased expression levels of genes related to antioxidant activity.
Assuntos
Doenças das Aves/prevenção & controle , Dieta/veterinária , Regulação da Expressão Gênica no Desenvolvimento , Transtornos de Estresse por Calor/veterinária , Metionina/uso terapêutico , Estresse Oxidativo , Músculos Peitorais/enzimologia , Animais , Animais Endogâmicos , Antioxidantes/administração & dosagem , Antioxidantes/uso terapêutico , Proteínas Aviárias/genética , Proteínas Aviárias/metabolismo , Betaína-Homocisteína S-Metiltransferase/genética , Betaína-Homocisteína S-Metiltransferase/metabolismo , Biomarcadores/sangue , Biomarcadores/metabolismo , Doenças das Aves/dietoterapia , Doenças das Aves/metabolismo , Doenças das Aves/patologia , Galinhas , Ingestão de Energia , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Glutationa Sintase/genética , Glutationa Sintase/metabolismo , Transtornos de Estresse por Calor/dietoterapia , Transtornos de Estresse por Calor/metabolismo , Transtornos de Estresse por Calor/prevenção & controle , Homocisteína/sangue , Canais Iônicos/genética , Canais Iônicos/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , Metionina/administração & dosagem , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Músculos Peitorais/metabolismo , Músculos Peitorais/patologia , Proteína Desacopladora 1 , Aumento de PesoRESUMO
Avaliaram-se o consumo de matéria seca, a produção de leite e os indicadores de estresse térmico de vacas Pardo-Suíça alimentadas com castanha de caju no semi-árido do Nordeste do Brasil. Doze animais foram distribuídos em um ensaio de reversão, com quatro tratamentos: 0, 8, 16 e 24 por cento de castanha no concentrado. As vacas receberam cana-de-açúcar à vontade e sete quilos de concentrado por dia. Maior consumo de matéria seca de cana-de-açúcar foi observado no tratamento com concentrado sem castanha (7,70kgMS/dia) em relação aos tratamentos com 16 por cento e 24 por cento de castanha (7,35 e 7,05kgMS/dia, respectivamente). O consumo no tratamento com concentrado sem castanha não diferiu do consumo no tratamento com 8 por cento (7,59kgMS/dia). Não houve efeito dos tratamentos sobre a produção de leite e sobre as variáveis indicativas de estresse térmico (P>0,05)
A study was carried out to evaluate dry matter intake, milk yield, and heat stress parameters in Brown Swiss cows fed diets with cashew nut. Animals were raised in the semi-arid region of the Brazilian Northeast. Twelve cows were subjected to a switch back experimental design, with four treatments: 0, 8, 16, and 24 percent of cashew nut in the concentrate. Each cow received 7kg of concentrate per day and had free access to sugar cane. Dry matter (DM) intake and milk yield were daily taken as well as measurements of rectal and milk temperature; and cardiac and respiratory rates. The highest intake of forage (sugar cane) was obtained when the concentrate had no cashew nut (7.7kgDM/day). This value was not different when the concentrate contained 8 percent of cashew nut (7.59kgDM/day) but greater than dry matter intake of cows receiving diets with 16 percent of cashew nut (7.35kgDM/day; P<0.05). The diet with 24 percent of cashew nut in the concentrate resulted in the lowest consumption of forage (7.05kgDM/day), which was significantly different from all other treatments (P<0.05). Variations in milk yield (from 14.76 to 15.31kg/day) were not related to changes in the content of cashew nut in the concentrate (P>0.05). Such low variability in daily milk yield could be associated with the higher energy density of diets containing more cashew nut. Finally, indicators of heat stress were not influenced by changes in the diets, given the air temperatures and environment where all cows were raised
Assuntos
Animais , Feminino , Bovinos , Anacardium , Leite , Transtornos de Estresse por Calor/dietoterapia , Transtornos de Estresse por Calor/veterináriaRESUMO
Avaliaram-se o consumo de matéria seca, a produção de leite e os indicadores de estresse térmico de vacas Pardo-Suíça alimentadas com castanha de caju no semi-árido do Nordeste do Brasil. Doze animais foram distribuídos em um ensaio de reversão, com quatro tratamentos: 0, 8, 16 e 24 por cento de castanha no concentrado. As vacas receberam cana-de-açúcar à vontade e sete quilos de concentrado por dia. Maior consumo de matéria seca de cana-de-açúcar foi observado no tratamento com concentrado sem castanha (7,70kgMS/dia) em relação aos tratamentos com 16 por cento e 24 por cento de castanha (7,35 e 7,05kgMS/dia, respectivamente). O consumo no tratamento com concentrado sem castanha não diferiu do consumo no tratamento com 8 por cento (7,59kgMS/dia). Não houve efeito dos tratamentos sobre a produção de leite e sobre as variáveis indicativas de estresse térmico (P>0,05)(AU)
A study was carried out to evaluate dry matter intake, milk yield, and heat stress parameters in Brown Swiss cows fed diets with cashew nut. Animals were raised in the semi-arid region of the Brazilian Northeast. Twelve cows were subjected to a switch back experimental design, with four treatments: 0, 8, 16, and 24 percent of cashew nut in the concentrate. Each cow received 7kg of concentrate per day and had free access to sugar cane. Dry matter (DM) intake and milk yield were daily taken as well as measurements of rectal and milk temperature; and cardiac and respiratory rates. The highest intake of forage (sugar cane) was obtained when the concentrate had no cashew nut (7.7kgDM/day). This value was not different when the concentrate contained 8 percent of cashew nut (7.59kgDM/day) but greater than dry matter intake of cows receiving diets with 16 percent of cashew nut (7.35kgDM/day; P<0.05). The diet with 24 percent of cashew nut in the concentrate resulted in the lowest consumption of forage (7.05kgDM/day), which was significantly different from all other treatments (P<0.05). Variations in milk yield (from 14.76 to 15.31kg/day) were not related to changes in the content of cashew nut in the concentrate (P>0.05). Such low variability in daily milk yield could be associated with the higher energy density of diets containing more cashew nut. Finally, indicators of heat stress were not influenced by changes in the diets, given the air temperatures and environment where all cows were raised(AU)