Efeito das estações do ano e da idade sobre as variáveis termofisiológicas e hematológicas de bezerros leiteiros mestiços em ambiente tropical / Effect of season and age on thermophysiological and hematological variables of crossbred dairy calves in tropical environment

Background: The wellbeing and performance of calves may be impaired if raised in high temperature environments. Physiological and hematological variables serve as a tool to assess the welfare of cattle; therefore, the influence of seasons and age on physiological and hematological variables was evaluated of crossbred dairy calves in a tropical environment.Materials, Methods & Results: Forty-two male and female calves were evaluated from July 2016 to July 2017, when the calves were of 2, 15, 30, and 60 days of age. Respiratory (RR) and heart rates (HR) and rectal (RT) and body surface (BST) temperatures were quantified in the morning. Additionally, in the morning, dry bulb (Tdb) and wet bulb (Twb) temperatures were measured, and then, relative humidity (RH) and a temperature-humidity index (THI) were calculated. Blood was collected to perform hemogram. The day before the calves were evaluated, thermal environment data were collected to verify whether there were cyclic periods of heat stress. The mean air temperature ranged from 19°C to 22.1°C, and the highest THI value of 68 occurred in the summer mornings. In the afternoon, the maximum air temperature ranged from 27.5°C to 29.7°C. In autumn, respiratory and heart rates and body surface temperature were higher in 2-day-old calves than in other ages. The body surface temperature of 60-day-old calves was higher in spring and summer than in autumn. Rectal temperature remained in the normal range throughout the study period. Season did not influence the erythrogram and plaquetogram. The values for red blood cells, MCV, MCHC, RDW, platelets, and MPV varied among the calf ages. Season did not influence the values of leukocytes, monocytes, lymphocytes, or N/L ratio; however, band neutrophils and eosinophils varied among seasons. Band neutrophils and monocytes were not altered by age, whereas leukocyte, segmented neutrophils, eosinophils, lymphocytes, and N/L ratio values varied with age among the calves.[...]

Efeito das estações do ano e da idade sobre as variáveis termofisiológicas e hematológicas de bezerros leiteiros mestiços em ambiente tropical / Effect of season and age on thermophysiological and hematological variables of crossbred dairy calves in tropical environment

Background: The wellbeing and performance of calves may be impaired if raised in high temperature environments. Physiological and hematological variables serve as a tool to assess the welfare of cattle; therefore, the influence of seasons and age on physiological and hematological variables was evaluated of crossbred dairy calves in a tropical environment.Materials, Methods & Results: Forty-two male and female calves were evaluated from July 2016 to July 2017, when the calves were of 2, 15, 30, and 60 days of age. Respiratory (RR) and heart rates (HR) and rectal (RT) and body surface (BST) temperatures were quantified in the morning. Additionally, in the morning, dry bulb (Tdb) and wet bulb (Twb) temperatures were measured, and then, relative humidity (RH) and a temperature-humidity index (THI) were calculated. Blood was collected to perform hemogram. The day before the calves were evaluated, thermal environment data were collected to verify whether there were cyclic periods of heat stress. The mean air temperature ranged from 19°C to 22.1°C, and the highest THI value of 68 occurred in the summer mornings. In the afternoon, the maximum air temperature ranged from 27.5°C to 29.7°C. In autumn, respiratory and heart rates and body surface temperature were higher in 2-day-old calves than in other ages. The body surface temperature of 60-day-old calves was higher in spring and summer than in autumn. Rectal temperature remained in the normal range throughout the study period. Season did not influence the erythrogram and plaquetogram. The values for red blood cells, MCV, MCHC, RDW, platelets, and MPV varied among the calf ages. Season did not influence the values of leukocytes, monocytes, lymphocytes, or N/L ratio; however, band neutrophils and eosinophils varied among seasons. Band neutrophils and monocytes were not altered by age, whereas leukocyte, segmented neutrophils, eosinophils, lymphocytes, and N/L ratio values varied with age among the calves.[...](AU)

The effect of cyclic heat stress applied to different broiler chicken brooding stages on animal performance and carcass yield

The objective of this study was to evaluate the performance and carcass yield of broilers submitted to heat stress during different rearing stages. A total of 840 one-day-old CobbAvian48TM male broilers were housed in an experimental house equipped with conventional ventilation system and foggers. Birds were distributed according to a completely randomized design into four treatments, with six replicates of 35 birds each. The treatments consisted of: T1 (control) - birds reared under natural temperature and relative humidity conditions from 1 to 42 days of age; T2 - birds submitted to heat stress (HS) from 16 to 21 days of age; T3 - birds submitted to HS from 22 to 42 days of age; and T4 - birds submitted to HS from 16 to 42 days of age. Birds were submitted to heat stress daily for one hour (12:00-13:00h).On day 42, performance data were determined. Six birds per replicate were selected and sacrificed to obtain carcass, parts, and giblet weights and yields. Performance parameters were not influenced by the treatments. Broilers submitted to 1-h cyclic heat between 16 and 42 days of age presented lower deboned breast weight compared with those maintained in natural temperature and relative humidity conditions. It was concluded that the performance of broilers submitted to short cyclic heat periods is not impaired.(AU)

The effect of cyclic heat stress applied to different broiler chicken brooding stages on animal performance and carcass yield

The objective of this study was to evaluate the performance and carcass yield of broilers submitted to heat stress during different rearing stages. A total of 840 one-day-old CobbAvian48TM male broilers were housed in an experimental house equipped with conventional ventilation system and foggers. Birds were distributed according to a completely randomized design into four treatments, with six replicates of 35 birds each. The treatments consisted of: T1 (control) - birds reared under natural temperature and relative humidity conditions from 1 to 42 days of age; T2 - birds submitted to heat stress (HS) from 16 to 21 days of age; T3 - birds submitted to HS from 22 to 42 days of age; and T4 - birds submitted to HS from 16 to 42 days of age. Birds were submitted to heat stress daily for one hour (12:00-13:00h).On day 42, performance data were determined. Six birds per replicate were selected and sacrificed to obtain carcass, parts, and giblet weights and yields. Performance parameters were not influenced by the treatments. Broilers submitted to 1-h cyclic heat between 16 and 42 days of age presented lower deboned breast weight compared with those maintained in natural temperature and relative humidity conditions. It was concluded that the performance of broilers submitted to short cyclic heat periods is not impaired.

Effects of the addition of pure glycerin supplementation in the drinking water on the performance of broilers submitted to heat stress and feed restriction

The experiment was conducted to study the effect of pure glycerin supplementation (GLYC) in the drinking water of broilers subjected to heat stress and feed restriction. Water with 0, 1, or 2% glycerin was provided ad libitum to broilers in six hours of feed restriction. The birds were housed in two environments: thermoneutral (TN) - 25 ° C, and cyclic heat stress (HS) - 12h with 250C, 6h with 320C, 3h of 250 to 320C and 3h of 320 to 250C. The experimental design was randomized in a factorial arrangement of 2 x 3 + 2, with three GLYC levels, two environments and one control group with ad libitum feeding each environment. When submitted to HS, broiler receiving 2% glycerin presented higher weight gain (WG), water consumption (WC), feed intake (FI) and energy consumption (EI) than those in the other treatments, contrarily to birds in TN, where increasing GLYC levels decreased those responses. Broilers submitted to feed restriction presented reduced FI, but better feed conversion (FCR), independently of rearing environment or GLYC levels. Broilers under HS submitted to feed restriction and receiving 2% GLYC presented higher WC (p < 0.05) and similar WG as the controls, differently from the restricted-fed broilers under TN receiving 2% GLYC, which WC and WG were lower than the controls. The inclusion of 2% pure glycerin in the drinking water may compensate the negative effects on performance caused by feed restriction in broilers submitted to heat stress.

Effects of the addition of pure glycerin supplementation in the drinking water on the performance of broilers submitted to heat stress and feed restriction

The experiment was conducted to study the effect of pure glycerin supplementation (GLYC) in the drinking water of broilers subjected to heat stress and feed restriction. Water with 0, 1, or 2% glycerin was provided ad libitum to broilers in six hours of feed restriction. The birds were housed in two environments: thermoneutral (TN) - 25 ° C, and cyclic heat stress (HS) - 12h with 250C, 6h with 320C, 3h of 250 to 320C and 3h of 320 to 250C. The experimental design was randomized in a factorial arrangement of 2 x 3 + 2, with three GLYC levels, two environments and one control group with ad libitum feeding each environment. When submitted to HS, broiler receiving 2% glycerin presented higher weight gain (WG), water consumption (WC), feed intake (FI) and energy consumption (EI) than those in the other treatments, contrarily to birds in TN, where increasing GLYC levels decreased those responses. Broilers submitted to feed restriction presented reduced FI, but better feed conversion (FCR), independently of rearing environment or GLYC levels. Broilers under HS submitted to feed restriction and receiving 2% GLYC presented higher WC (p < 0.05) and similar WG as the controls, differently from the restricted-fed broilers under TN receiving 2% GLYC, which WC and WG were lower than the controls. The inclusion of 2% pure glycerin in the drinking water may compensate the negative effects on performance caused by feed restriction in broilers submitted to heat stress.(AU)

Global warming influence on climatic variables and thermal comfort index in Paraíba state, Brazil / Influência do aquecimento global sobre as variáveis climatológicas e índice de conforto térmico no estado da Paraíba, Brasil

The increase in the concentration of greenhouse gases originated from burning fossil fuels, along with breeding, been appointed as the main causes of global climate change resulting from global warming in earth"s atmosphere. These changes can cause serious impacts on the lives and livestock production mainly in tropical regions. Therefore, the aim with this work was to evaluate the effect of global warming on the climatological variables, thermal comfort index and animal production in the state of Paraiba. For this meteorological data from four meteorological stations by state and calculated the temperature humidity index used. The means analyzed from the difference between the normal period of 30 years (1961 to 1990) and the period of the last four years (2011-2015). The results showed that all regions of the state are suffering from climate change due to global warming and that there was an average elevation of ITU in recent years, indicating that changes in attitude should be intensified to allow the survival and productivity of animals does not become increasingly costly in the state.(AU)

O aumento na concentração de gases poluentes, originados da queima de combustíveis fósseis, juntamente com a criação de animais, tem sido apontado como as principais causas das mudanças climáticas globais decorrentes do efeito estufa na atmosfera da terra. Essas mudanças podem causar sérios impactos sobre a vida e a produção animal, principalmente nas regiões tropicais. Portanto, objetivou-se com esse trabalho avaliar o efeito do aquecimento global sobre as variáveis climatológicas, índice de conforto térmico e produção animal no estado da Paraíba. Para isso foram utilizados os dados meteorológicos de quatro estações meteorológicas distribuídas pelo estado e calculado o índice de temperatura e umidade. As médias obtidas foramanalisadas a partir da diferença entre o período das normais 30 anos (1961-1990) e o período dos últimos quatro anos (2011-2015). Os resultados demonstraram que todas as regiões do estado estão sofrendo mudanças climáticas devido ao efeito estufa e que houve uma elevação média do ITU nosúltimos anos, indicando que mudanças de atitude devem ser intensificadas para permitir que a sobrevivência e a produtividade dos animais não se torne cada vez mais dispendiosa dentro do estado.(AU)

Global warming influence on climatic variables and thermal comfort index in Paraíba state, Brazil / Influência do aquecimento global sobre as variáveis climatológicas e índice de conforto térmico no estado da Paraíba, Brasil

The increase in the concentration of greenhouse gases originated from burning fossil fuels, along with breeding, been appointed as the main causes of global climate change resulting from global warming in earth"s atmosphere. These changes can cause serious impacts on the lives and livestock production mainly in tropical regions. Therefore, the aim with this work was to evaluate the effect of global warming on the climatological variables, thermal comfort index and animal production in the state of Paraiba. For this meteorological data from four meteorological stations by state and calculated the temperature humidity index used. The means analyzed from the difference between the normal period of 30 years (1961 to 1990) and the period of the last four years (2011-2015). The results showed that all regions of the state are suffering from climate change due to global warming and that there was an average elevation of ITU in recent years, indicating that changes in attitude should be intensified to allow the survival and productivity of animals does not become increasingly costly in the state.

O aumento na concentração de gases poluentes, originados da queima de combustíveis fósseis, juntamente com a criação de animais, tem sido apontado como as principais causas das mudanças climáticas globais decorrentes do efeito estufa na atmosfera da terra. Essas mudanças podem causar sérios impactos sobre a vida e a produção animal, principalmente nas regiões tropicais. Portanto, objetivou-se com esse trabalho avaliar o efeito do aquecimento global sobre as variáveis climatológicas, índice de conforto térmico e produção animal no estado da Paraíba. Para isso foram utilizados os dados meteorológicos de quatro estações meteorológicas distribuídas pelo estado e calculado o índice de temperatura e umidade. As médias obtidas foramanalisadas a partir da diferença entre o período das normais 30 anos (1961-1990) e o período dos últimos quatro anos (2011-2015). Os resultados demonstraram que todas as regiões do estado estão sofrendo mudanças climáticas devido ao efeito estufa e que houve uma elevação média do ITU nosúltimos anos, indicando que mudanças de atitude devem ser intensificadas para permitir que a sobrevivência e a produtividade dos animais não se torne cada vez mais dispendiosa dentro do estado.

Glutamic acid improves body weight gain and intestinal morphology of broiler chickens submitted to heat stress

The objective of this study was to evaluate the effects of 1% dietary glutamic acid on the body weight, intestinal morphometry, and anti-Newcastle antibody titers of broiler chickens submitted to heat stress. One-d-old male broiler chicks (n=120) were distributed according to a 2 x 2 factorial design with two environmental temperatures (thermoneutral or heat stress) and two diets (with 0 or 1% glutamic acid). Heat stress temperature was constantly maintained (24h/day) 5 ºC higher than the thermoneutral temperature. Diets supplied the nutritional requirements of broilers in the pre-starter (1 to 7d) and starter (8 to 21d) phases. Birds were vaccinated against Newcastle disease on d 7 via eye drop. On days 5, 10, 15, and 20, individual body weight was determined, serum samples were collected from five birds, and duodenum samples were collected from four birds per treatment. Serum anti-Newcastle antibody titers were determined by enzyme immunoassay and transformed into log10. Villus height, crypt depth, and villus: crypt ratio were measured in the duodenum. Data were analyzed by ANOVA. Chronic heat stress negatively affected body weight and intestinal morphometry during the pre-starter and starter phases, but had no effect on antibody titers. Dietary glutamic acid supplementation (1%) improved body weight and intestinal integrity of birds submitted to heat stress when compared with non-supplemented and heat-stressed birds.(AU)

Glutamic acid improves body weight gain and intestinal morphology of broiler chickens submitted to heat stress

The objective of this study was to evaluate the effects of 1% dietary glutamic acid on the body weight, intestinal morphometry, and anti-Newcastle antibody titers of broiler chickens submitted to heat stress. One-d-old male broiler chicks (n=120) were distributed according to a 2 x 2 factorial design with two environmental temperatures (thermoneutral or heat stress) and two diets (with 0 or 1% glutamic acid). Heat stress temperature was constantly maintained (24h/day) 5 ºC higher than the thermoneutral temperature. Diets supplied the nutritional requirements of broilers in the pre-starter (1 to 7d) and starter (8 to 21d) phases. Birds were vaccinated against Newcastle disease on d 7 via eye drop. On days 5, 10, 15, and 20, individual body weight was determined, serum samples were collected from five birds, and duodenum samples were collected from four birds per treatment. Serum anti-Newcastle antibody titers were determined by enzyme immunoassay and transformed into log10. Villus height, crypt depth, and villus: crypt ratio were measured in the duodenum. Data were analyzed by ANOVA. Chronic heat stress negatively affected body weight and intestinal morphometry during the pre-starter and starter phases, but had no effect on antibody titers. Dietary glutamic acid supplementation (1%) improved body weight and intestinal integrity of birds submitted to heat stress when compared with non-supplemented and heat-stressed birds.

Qualidade de carne e ocorrência de pododermatite em frangos de corte criados em cama com acidificante em diferentes períodos sazonais

Os parâmetros qualitativos da carne de frango e a ocorrência de pododermatite tem relação direta com o bem-estar dos frangos de corte. Deste modo, a má qualidade da cama altera o microambiente expondo as aves a uma situação de estresse, além de ser um agravante para a ocorrência de pododermatite. Portanto, o uso do acidificante é uma estratégia para promover um ambiente agradável às aves durante os diferentes períodos climáticos. Neste sentido, o capítulo 1 (Revisão bibliográfica), teve o objetivo abordar fatores relacionados à qualidade da cama de frango e a sua interferência sobre os parâmetros de bem-estar de frango de corte, enfatizando a ocorrência de pododermatite e as características qualitativas da carne de frango. E no capítulo 2, objetivou-se avaliar a influência de diferentes períodos sazonais e o uso de tratamento químico com características acidificantes na qualidade física da cama, ocorrência de pododermatite e qualidade de carne de frangos de corte. Para tanto, foram avaliados quatro períodos sazonais consecutivos ao longo do ano utilizando quatro aviários por ciclo, com densidade de criação de 12 aves/m2. A cama de dois dos aviários foi tratada com o composto a base de sulfato de cálcio ativado com ácido sulfúrico e filossilicato expandido, aplicado na superfície da cama em duas etapas (antes do alojamento das aves e aos 12 dias de idade das aves) em cada ciclo. Utilizou-se o delineamento inteiramente casualizado com o esquema fatorial 4X2 para as avaliações dos parâmetros qualitativos e análise sensorial da carne, esquema de parcela subdividida no tempo com fatorial na parcela (5X2) para as avaliações de umidade e temperatura superficial da cama e foi utilizado dois tratamentos (cama acidificada e cama sem tratamento) e diferentes períodos sazonais (1º ao 4º período) para as avaliações de pododermatite. Foram avaliadas a umidade e temperatura superficial da cama e as lesões de pododermatite. Para as avaliações dos parâmetros qualitativo e sensoriais da carne de peito de frangos foram selecionados aos 42 dias de criação 100 frangos machos por ciclo que foram submetidas ao processo de abate, coletou-se os músculos Pectoralis major e após 24 horas mensurou pH, cor objetiva, perda por exsudação, perda por cocção, força de cisalhamento e análise sensorial. O condicionador químico aplicado na cama mostrou-se eficiente em adsorver a umidade da cama durante o período com elevado índice pluviométrico, e reduziu a incidência das lesões podais durante os diferentes períodos sazonais aos 28 dias de idade das aves e se mostrou mais eficiente aos 42 dias em períodos de transição entre a seca para a chuvosa e de elevada pluviosidade, mas não influenciou os parametros qualitativos e sensorial da carne de frango. Épocas com elevadas temperatura ambiental e umidade relativa do ar, como no 1º período, podem resultar em alterações nas características qualititativas da carne. As aves apresentam menor incidência de pododermatite durante o período de transição chuva/seca. Porém, o período com maior índice pluviômetro proporcionou maior incidência de pododermatite nos frangos de corte. Conclui-se que o composto aplicado na cama adsorve a umidade da cama e reduz a incidência de pododermatite em frangos. As aves apresentam menor incidência de pododermatite durante o período de transição do chuvoso para o período seco. O período com maior índice pluviômetro proporciona maior incidência de lesões e promove modificações sobre os parâmetros qualitativos da carne de frango de corte.

Qualitative parameters of broilers meat the foot pad dermatitis incidence is directly related to the welfare of broilers. In this way, the poor quality of the litter changes the microenvironment exposing the broiler to a situation of stress, in addition to being an aggravating factor for the footpad dermatitis incidence. Therefore, the use of acidifying is a strategy to promote a pleasant environment to broiler during the different periods climatic. In this sense, the chapter 1 (literature review), aimed to address factors related to the quality of the broiler and your litter interference on broiler welfare, emphasizing the footpad dermatitis incidences and the quality characteristics chicken of meat. And in Chapter 2, the objective of assessing the influence of different seasonal periods and the use of chemical treatment with acidifying features on physical quality of litter, the footpad dermatitis incidence and meat quality of broilers. To this end, four consecutive seasonal periods were evaluated throughout the year using four aviaries per cycle, with a density of creation of 12 birds/m². The litter of two of the aviaries was treated with the compound based on calcium sulfate activated with sulfuric acid and expanded filosilicate, applied on the surface of the litter in two steps (before the accommodation of birds and 12 days of age of birds) in each cycle. A completely randomized design with the 4X2 factorial scheme was used to evaluate the qualitative parameters and the sensorial analysis of meat, subdivided parcel scheme in time with factorial on the parcel (5x2) to the reviews of moisture and surface temperature of the litter and was used two treatments (acid litter and litter without treatment) and seasonal periods (1st to 4th period) for evaluations of footpad dermatitis. Were evaluated moisture and surface temperature of the litter and the injuries footpad dermatitis. For the qualitative parameters and sensory assessments of broiler of breast meat were selected to 42 days of creating 100 male broiler per cycle that were subjected to the process of slaughtering, collected the muscles Pectoralis major and after 24 hours measured the pH, objective color (L*, a* and b* value), drip loss, cooking loss, shear force and sensory analysis. Chemical conditioner applied in litter was shown to be efficient in adsorb moisture from the litter during the period of high rainfall, and reduced the footpad dermatitis during seasonal periods to 28 days of age of birds and proved to be more efficient to 42 days in periods of transition from the dry to the rainy season and high rainfall, but did not influence the qualitative and sensory parameters of broiler meat. Times with high ambient temperature and relative humidity, as in the first period, may result in changes to the features qualitative of the meat. The birds present lower footpad dermatitis during the transitional period the rain/dry. However the period with highest rain gauge resulted in higher footpad dermatitis in broilers. It is concluded that the compound applied in bed absorbs moisture from the litter and reduces the footpad dermatitis in broilers. The birds present lower footpad dermatitis during the period of transition from the rainy to dry season. The period with highest rain gauge provides greater footpad dermatitis and promotes changes on the qualitative parameters of broiler meat.

Crude protein and metabolizable energy levels for layers reared in hot climates

The objective of the present study was to evaluate the effects of different dietary crude protein (CP) and metabolizable energy (ME) levels on the performance, internal and external egg quality, and cloacal temperature of commercial layers reared in hot climate. In this trial, 100 commercial Hy-Line W-36 layers between 20 and 32 weeks of age were distributed according to a completely randomized experimental design with a 2 x 2 factorial arrangement, consisting of two CP levels (15 e 18%) and two ME contents (2700 and 3100 kcal/kg) with five replicates per treatment and 10 birds per replicate. Performance (feed intake, egg production, egg mass, and feed conversion ratio), internal (Haugh units and albumen and yolk percentage) and external (eggshell % and thickness) egg quality parameters were evaluated. Cloacal temperature was measured in two birds per replicate at 8:00 h and 13:00 h. The diet containing 2700 kcal ME/kg promoted the best performance, whereas the worse performance observed in birds fed the diet with 3100 ME/kg was partially recovered when the diet contained 18% CP. Haugh units worsened as dietary CP level increased. The other external and internal egg quality parameters were not affected by dietary CP or ME levels. The cloacal temperature of birds fed 15% CP was lower in the morning and higher in the afternoon relative to those fed 18% CP, which temperature did not change during the day. It was concluded that dietary CP and ME levels influenced the performance and the body temperature of commercial layers.(AU)

Crude protein and metabolizable energy levels for layers reared in hot climates

The objective of the present study was to evaluate the effects of different dietary crude protein (CP) and metabolizable energy (ME) levels on the performance, internal and external egg quality, and cloacal temperature of commercial layers reared in hot climate. In this trial, 100 commercial Hy-Line W-36 layers between 20 and 32 weeks of age were distributed according to a completely randomized experimental design with a 2 x 2 factorial arrangement, consisting of two CP levels (15 e 18%) and two ME contents (2700 and 3100 kcal/kg) with five replicates per treatment and 10 birds per replicate. Performance (feed intake, egg production, egg mass, and feed conversion ratio), internal (Haugh units and albumen and yolk percentage) and external (eggshell % and thickness) egg quality parameters were evaluated. Cloacal temperature was measured in two birds per replicate at 8:00 h and 13:00 h. The diet containing 2700 kcal ME/kg promoted the best performance, whereas the worse performance observed in birds fed the diet with 3100 ME/kg was partially recovered when the diet contained 18% CP. Haugh units worsened as dietary CP level increased. The other external and internal egg quality parameters were not affected by dietary CP or ME levels. The cloacal temperature of birds fed 15% CP was lower in the morning and higher in the afternoon relative to those fed 18% CP, which temperature did not change during the day. It was concluded that dietary CP and ME levels influenced the performance and the body temperature of commercial layers.

Performance and egg quality of Japanese quails submitted to cyclic heat stress

Aiming at evaluating the influence of cyclic temperatures on the performance and egg quality of Japanese quails an experiment was carried out with 480 birds after egg production peak. Birds were housed in a bioclimatic chamber with automatic temperature control that contained two rooms, one maintained at thermoneutral temperature (21 ºC) and the other adjusted for the tested cyclic temperatures (24, 27, 30, 33 and 36 ºC at a time). Each room had a battery of five floors and ten cages, with a capacity of 24 birds per cage, totaling 240 birds per battery. Birds were fed iso-nutritious and iso-caloric diets. Data obtained under the tested cyclic temperatures were compared with those obtained under thermoneutral temperature. At the end of each experimental period (14 days) performance and egg quality parameters were evaluated. A completely randomized experimental design with two treatments (thermoneutral temperature and tested temperature) and ten replicates of 24 birds each. Cyclic increases of 27 ºC and higher in environmental temperature negatively affected bird performance, with reduced feed intake and consequent reductions in egg weight and mass. A cyclic increase of the environmental temperature to 36 ºC reduced the percentage of saleable eggs and egg production.(AU)

Performance and egg quality of Japanese quails submitted to cyclic heat stress

Aiming at evaluating the influence of cyclic temperatures on the performance and egg quality of Japanese quails an experiment was carried out with 480 birds after egg production peak. Birds were housed in a bioclimatic chamber with automatic temperature control that contained two rooms, one maintained at thermoneutral temperature (21 ºC) and the other adjusted for the tested cyclic temperatures (24, 27, 30, 33 and 36 ºC at a time). Each room had a battery of five floors and ten cages, with a capacity of 24 birds per cage, totaling 240 birds per battery. Birds were fed iso-nutritious and iso-caloric diets. Data obtained under the tested cyclic temperatures were compared with those obtained under thermoneutral temperature. At the end of each experimental period (14 days) performance and egg quality parameters were evaluated. A completely randomized experimental design with two treatments (thermoneutral temperature and tested temperature) and ten replicates of 24 birds each. Cyclic increases of 27 ºC and higher in environmental temperature negatively affected bird performance, with reduced feed intake and consequent reductions in egg weight and mass. A cyclic increase of the environmental temperature to 36 ºC reduced the percentage of saleable eggs and egg production.

RELAÇÕES ENERGIA: PROTEÍNA E SUBSTITUIÇÃO ISOENERGÉTICA DOS MACROINGREDIENTES DA DIETA DE CODORNAS EUROPEIAS CRIADAS EM AMBIENTES DE CONFORTO E DE ESTRESSE PELO CALOR

Este estudo teve como objetivo avaliar a substituição do amido de milho (AMI) pelo óleo de soja (OLS) ou proteína isolada de soja (PIS), respectivamente, como fontes de energia de carboidratos, lipídios e proteínas em dietas de baixa relação energia (E): proteína (P) (108 kcal E: 1% P ou 2950 kcal EMAn: 27,3% PB), de média relação ou controle (128 kcal E: 1% P ou 2950 kcal EMAn: 23% PB) e de alta relação E: P (148 kcal E: 1% P ou 2,950: 19,9% PB) na dieta de codornas europeias de 10 a 35 dias de idade alojadas em termoneutralidade (26° C) ou em temperatura de estresse pelo calor (35° C). Um total de 588 codornas foram utilizadas, metade em ambiente termoneutro e metade em ambiente quente, distribuídas em delineamento inteiramente casualizado em esquema fatorial (3 x 2 +1) x 2 [(3 fontes de energia x 2 relação E: P + 1 dieta controle) x duas temperaturas], resultando em quatorze tratamentos com sete repetições de seis aves. Exceto o tratamento controle, parte da energia das dietas de baixa ou alta relação E: P do AMI (12,46% na dieta) foi substituída pela energia do OLS (5,00% na dieta) ou pela energia da PIS (12,04% na dieta). Para a análise da histologia da mucosa do intestino delgado (altura de vilo, largura de vilo, profundidade de cripta, relação vilosidade: cripta e área de absorção) foram utilizadas quatro aves por tratamento, sendo coletadas amostras de aproximadamente 1 cm da porção média do duodeno, jejuno e íleo de cada ave. Os dados foram analisadas pelo Teste de Duncan (P0,05). A adição de AMI e OLS na dieta melhorou (P0,05) o consumo de ração, ganho de peso e conversão alimentar em comparação com a adição de PIS, respectivamente. A baixa relação E: P influenciou positivamente o ganho de peso e a conversão alimentar, quando comparada com a alta relação E: P (P0,05). As codornas alojadas em temperatura moderada tiveram melhor consumo de ração e ganho de peso, mas a conversão alimentar foi pior em comparação com as codornas alojadas em temperatura elevada (P0,05). Houve interações (P0,05) entre a fonte de energia e a relação E: P. A alta relação E: P diminuiu o consumo de ração e o ganho de peso quando a dieta continha PIS (P0,05). A baixa relação E: P reduziu o consumo de ração, mas melhorou o ganho de peso e a conversão alimentar quando o OLS substituiu o AMI na dieta (P0,05). A substituição do AMI pela PIS aumentou o consumo de ração e melhorou a conversão alimentar (P0,05). A substituição de AMI por OLS ou PIS não melhorou o desempenho de codornas alojadas em temperatura quente. Quando alimentadas com dietas com baixa relação E: P (108: 1% PB) contendo AMI ou OLS as codornas tiveram melhor ganho de peso e conversão alimentar que codornas alimentadas com PIS. A dieta controle influenciou positivamente a conversão alimentar quando comparada com as dietas de alta relação E: P contendo AMI, OLS e PIS. A PIS como fonte de energia e a temperatura de 35° C têm impacto negativo sobre o desempenho das codornas. A substituição do AMI pelo OLS atenua o efeito negativo da alta temperatura sobre o ganho de peso das codornas. A relação de 128/1% ou 23% de proteína aumenta a área de absorção da região do duodeno no conforto térmico e dos segmentos jejuno e íleo no estresse térmico.

The objective of this study was to evaluate the substitution of soybean oil (OLS) or isolated soy protein (PIS), as energy sources of carbohydrates, lipids and proteins in low energy (E) diets, respectively: protein (P) (108 kcal E: 1% P or 2950 kcal EMAn: 27.3% PB), control (128 kcal E: 1% P or 2950 kcal EMAn: 23% PB) or high E: P (128 kcal E: 1% P or 2950 kcal EMAn: 23.0% CP) in the diet of European quails from 10 to 35 days of age. age in room temperature thermoneutral (26 ° C) or hot (35 ° C). A total of 588 quails were used, half in thermoneutral environment, and half in warm environment, distributed in a completely randomized design in a factorial scheme (3 x 2 +1) x 2 [(3 energy sources x 2 E: P + 1 ratio diet control) x two temperatures], resulting in fourteen treatments with seven replicates of six birds. The energy of the starch (12.46% in the diet) was replaced by the energy of the OLS (5.00% in the diet) or the energy of the PIS (12.04% in the diet) within each diet of low E: P ratio or high. For the analysis of the histology of the small intestine mucosa, four birds per treatment were used, and samples of approximately 1 cm of the middle portion of the duodenum, jejunum and ileum of each bird were collected, the variables analyzed were villi height, depth of crypt, relationship villus: crypt and absorption area. Data were analyzed by Duncan's test (P0.05). The addition of starch and OLS in the diet improved (P0.05) feed intake, weight gain and feed conversion compared to the addition of PIS, respectively. The low E: P ratio positively influenced weight gain and feed conversion, when compared to the high E: P ratio (P0.05). Quails housed at moderate temperature had better feed intake and weight gain, but feed conversion was worse compared to quails housed at elevated temperature (P0.05). There were interactions (P0.05) between the energy source and the E: P ratio. The high E: P ratio decreased feed intake and weight gain when the diet contained PIS (P0.05). The low E: P ratio reduced feed intake, but improved weight gain and feed conversion when OLS replaced starch in the diet (P0.05). The replacement of starch by PIS increased feed intake and improved feed conversion (P0.05). The replacement of starch by OLS or PIS did not improve the performance of quails housed at hot temperature. Quails fed diets with low E: P ratio (108: 1 - 27.3% CP and 2,950 EMAn) with corn starch or OLS have better weight gain and feed conversion than quails fed with isolated soy protein as a source of energy. The control diet positively influenced the feed conversion when compared to the high E: P diets containing starch, OLS and PIS. Soya protein isolates as a source of energy and temperature of 35 ° C have a negative impact on the performance of quails. The replacement of starch by soybean oil attenuates the negative effect of high temperature on quail weight gain. The ratio of 128/1% or 23% of protein increases the area of absorption of the duodenum region in thermal comfort and the jejunum and ileum segments in thermal stress.

Efeito da temperatura ambiente e da idade do frango sobre o valor energético do farelo de soja / Effects of environmental temperature and age of broilers on energy value of soybean meal

Foram utilizados 288 pintos de corte Cobb, distribuídos em delineamento experimental inteiramente ao acaso, em esquema de parcelas subdivididas no tempo, sendo as três temperaturas de criação - fria, termoneutra e quente - as parcelas, e as três fases de avaliação - inicial, crescimento e final - as subparcelas, com seis repetições de seis aves cada. A dieta-teste foi obtida pela substituição de parte da ração basal pelo alimento-teste: 40 por cento do farelo de soja + 60 por cento da ração basal. Foram calculados os coeficientes de metabolizabilidade aparente e verdadeiro da matéria seca, do nitrogênio, do extrato etéreo da dieta-teste e os valores de energia metabolizável aparente e verdadeira (EMA e EMV), e corrigidas pelo balanço de nitrogênio do farelo de soja (EMAn e EMVn). Foram encontrados valores médios de EMAn do farelo de soja para aves criadas em temperatura fria, termoneutra e quente de 2110, 2016 e 2022kcal/kg, respectivamente, e para as fases de criação inicial, crescimento e final de 1840, 2052 e 2256kcal/kg, respectivamente. O valor de energia metabolizável do farelo de soja, os balanços e os coeficientes de metabolizabilidade dos nutrientes da dieta-teste aumentaram com a idade do frango de corte, porém não são afetados pela temperatura ambiente.(AU)

Two hundred and eighty-eight Cobb chicks were distributed in a completely randomized design with a split-plot arrangement with six replication of six chicks each, the main plots were in three temperatures (cold, thermo neutral and hot) and the secondary plot were by phase (initial, growing and final). The test diet was produced by replacing the basal diet with test food: 40 percent soybean meal+60 percent basal diet. The coefficient of apparent and true metabolizability of dry matter, nitrogen, ether extract of the test diet and apparent and true metabolizable energies (AME and TME) of soybean meal were calculated and energy values were corrected for nitrogen balance (AMEn and TMEn) of soybean meal, in kcal/kg, as fed basis. The mean values of AMEn observed for broiler chicks in cold, thermo neutral and hot temperature were 2110, 2016 and 2022kcal/kg, respectively, and the initial, growing and final phases were 1840, 2052 and 2256kcal/kg, respectively. The metabolizable energy values of soybean meal, the balance and coefficients of metabolizability of the nutrients of the test diet increased with the age of broiler; however, they were not affected by environmental temperature.(AU)

Efeito da temperatura ambiente e da idade do frango sobre o valor energético do farelo de soja

Two hundred and eighty-eight Cobb chicks were distributed in a completely randomized design with a split-plot arrangement with six replication of six chicks each, the main plots were in three temperatures (cold, thermo neutral and hot) and the secondary plot were by phase (initial, growing and final). The test diet was produced by replacing the basal diet with test food: 40% soybean meal+60% basal diet. The coefficient of apparent and true metabolizability of dry matter, nitrogen, ether extract of the test diet and apparent and true metabolizable energies (AME and TME) of soybean meal were calculated and energy values were corrected for nitrogen balance (AMEn and TMEn) of soybean meal, in kcal/kg, as fed basis. The mean values of AMEn observed for broiler chicks in cold, thermo neutral and hot temperature were 2110, 2016 and 2022kcal/kg, respectively, and the initial, growing and final phases were 1840, 2052 and 2256kcal/kg, respectively. The metabolizable energy values of soybean meal, the balance and coefficients of metabolizability of the nutrients of the test diet increased with the age of broiler; however, they were not affected by environmental temperature.

Foram utilizados 288 pintos de corte Cobb, distribuídos em delineamento experimental inteiramente ao acaso, em esquema de parcelas subdivididas no tempo, sendo as três temperaturas de criação - fria, termoneutra e quente - as parcelas, e as três fases de avaliação - inicial, crescimento e final - as subparcelas, com seis repetições de seis aves cada. A dieta-teste foi obtida pela substituição de parte da ração basal pelo alimento-teste: 40% do farelo de soja + 60% da ração basal. Foram calculados os coeficientes de metabolizabilidade aparente e verdadeiro da matéria seca, do nitrogênio, do extrato etéreo da dieta-teste e os valores de energia metabolizável aparente e verdadeira (EMA e EMV), e corrigidas pelo balanço de nitrogênio do farelo de soja (EMAn e EMVn). Foram encontrados valores médios de EMAn do farelo de soja para aves criadas em temperatura fria, termoneutra e quente de 2110, 2016 e 2022kcal/kg, respectivamente, e para as fases de criação inicial, crescimento e final de 1840, 2052 e 2256kcal/kg, respectivamente. O valor de energia metabolizável do farelo de soja, os balanços e os coeficientes de metabolizabilidade dos nutrientes da dieta-teste aumentaram com a idade do frango de corte, porém não são afetados pela temperatura ambiente.

Impact of global warming on beef cattle production cost in Brazil

Global warming is affecting agribusiness in its economic aspects. Therefore, the prediction of the evolution of Brazilian beef cattle production cost was made using the IPCC forecast scenario for global warming. The methodology consisted of two steps: (i) the development of a fuzzy model that estimated the grazing land capacity (RP) decrease risk as a function of the changes in the average total rain index, air temperature and increase in extension of the dry season; and (ii) the design of an algorithm for predicting the decrease in production as function of the RPfuzzy model, that results in the impact in beef cattle productivity, and consequent increase in production costs. Historical environmental data from important producing counties in the Cerrado were organized and a set of fuzzy Gaussian functions were developed, and three possible settings (optimistic, medium and pessimistic) were considered. The decrease in beef cattle productivity was estimated using the losses in production due to the increase in air temperature and vulnerability of pasture capacity. The boundary settings for the total increase of production cost scenario used the number of animals per area of grazing land, the adoption of grain supplement and its future scenario; and the result output function pointed to a threshold within a variation from an increase in production cost of 80% (optimistic) to 160% (pessimistic). Under the optimistic scenario the total cost of Brazilian beef cattle production in the Cerrado became near to US$ 2.88 kg-1, while in the pessimistic scenario this cost reached US$ 4.16 kg-1, challenging the international competitiveness of this economic segment.

O aquecimento global afeta o agronegócio em seus aspectos econômicos. Foi feita previsão daevolução do custo de produção de carne bovina brasileira usando a predição de aquecimento global do IPCC. A metodologia consistiu de duas etapas: (i) o desenvolvimento de modelo fuzzy que estimou o risco de decréscimo da capacidade de pastagens (RP) em função das mudanças no índice pluviométrico total, na temperatura do ar e na extensão da estação de seca; e (ii) o desenvolvimento de um algoritmo para predição do decréscimo da produção em função de um modelo fuzzy de RP que resulte no impacto na produtividade bovina de corte e conseqüente aumento no custo de produção. Foram organizados os dados históricos de fatores ambientais dos municípios importante produção no Cerrado e um conjunto de funções Gaussianas fuzzy foi desenvolvido e três estimativas possíveis (otimista, média e negativa) foram consideradas. O decréscimo na produtividade do gado foi estimado usando as perdas de produção devido ao acréscimo da temperatura bem como da vulnerabilidade da capacidade de pastagem. O estabelecimento dos limites para o cenário do acréscimo do custo de produção usou o número de unidade animal por área de pastagem, a adoção de suplemento de grãos e o cenário de produção futura; e o resultado da função de saída apontou para uma variação do acréscimo do custo de produção de 80% (otimista) até 160% (pessimista). Sob o cenário otimista, o custo total da produção brasileira de carne bovina no Cerrado chega a US$ 2,88 kg-1, enquanto no cenário pessimista este custo pode atingir US$ 4,16 kg-1, o que pode comprometer a competitividade internacional do setor.

Impact of global warming on beef cattle production cost in Brazil

Global warming is affecting agribusiness in its economic aspects. Therefore, the prediction of the evolution of Brazilian beef cattle production cost was made using the IPCC forecast scenario for global warming. The methodology consisted of two steps: (i) the development of a fuzzy model that estimated the grazing land capacity (RP) decrease risk as a function of the changes in the average total rain index, air temperature and increase in extension of the dry season; and (ii) the design of an algorithm for predicting the decrease in production as function of the RPfuzzy model, that results in the impact in beef cattle productivity, and consequent increase in production costs. Historical environmental data from important producing counties in the Cerrado were organized and a set of fuzzy Gaussian functions were developed, and three possible settings (optimistic, medium and pessimistic) were considered. The decrease in beef cattle productivity was estimated using the losses in production due to the increase in air temperature and vulnerability of pasture capacity. The boundary settings for the total increase of production cost scenario used the number of animals per area of grazing land, the adoption of grain supplement and its future scenario; and the result output function pointed to a threshold within a variation from an increase in production cost of 80% (optimistic) to 160% (pessimistic). Under the optimistic scenario the total cost of Brazilian beef cattle production in the Cerrado became near to US$ 2.88 kg-1, while in the pessimistic scenario this cost reached US$ 4.16 kg-1, challenging the international competitiveness of this economic segment.

O aquecimento global afeta o agronegócio em seus aspectos econômicos. Foi feita previsão daevolução do custo de produção de carne bovina brasileira usando a predição de aquecimento global do IPCC. A metodologia consistiu de duas etapas: (i) o desenvolvimento de modelo fuzzy que estimou o risco de decréscimo da capacidade de pastagens (RP) em função das mudanças no índice pluviométrico total, na temperatura do ar e na extensão da estação de seca; e (ii) o desenvolvimento de um algoritmo para predição do decréscimo da produção em função de um modelo fuzzy de RP que resulte no impacto na produtividade bovina de corte e conseqüente aumento no custo de produção. Foram organizados os dados históricos de fatores ambientais dos municípios importante produção no Cerrado e um conjunto de funções Gaussianas fuzzy foi desenvolvido e três estimativas possíveis (otimista, média e negativa) foram consideradas. O decréscimo na produtividade do gado foi estimado usando as perdas de produção devido ao acréscimo da temperatura bem como da vulnerabilidade da capacidade de pastagem. O estabelecimento dos limites para o cenário do acréscimo do custo de produção usou o número de unidade animal por área de pastagem, a adoção de suplemento de grãos e o cenário de produção futura; e o resultado da função de saída apontou para uma variação do acréscimo do custo de produção de 80% (otimista) até 160% (pessimista). Sob o cenário otimista, o custo total da produção brasileira de carne bovina no Cerrado chega a US$ 2,88 kg-1, enquanto no cenário pessimista este custo pode atingir US$ 4,16 kg-1, o que pode comprometer a competitividade internacional do setor.