Níveis de energia metabolizável em rações para frangos de corte mantidos em ambiente de alta temperatura

Quatrocentas aves com peso médio de 675,00 g foram distribuídas em delineamento de blocos casualizados, com base no peso das aves, com cinco tratamentos e quatro repetições. As dietas experimentais foram constituídas de cinco níveis de energia metabolizável (2.800, 2.900, 3.000, 3.100 e 3.200 kcal de EM/kg de ração) formuladas para atender às exigências nutricionais, exceto de energia metabolizável. O aumento do nível de energia das rações foi obtido pela adição de óleo de soja. Realizaram-se análises de variância e de regressão, associando-se os níveis de energia aos valores das variáveis estudadas. As aves foram avaliadas quanto ao desempenho (consumo de ração, ganho de peso e conversão alimentar) e às características de carcaça nos períodos de 22 a 35 dias, 36 a 42 dias, 43 aos 49 dias e de 22 a 49 dias de idade. O ganho de peso e a conversão alimentar de frangos de corte da linhagem Hubbard mantidos em ambiente de alta temperatura não são influenciados pelos níveis de energia metabolizável da ração. Os níveis de energia da dieta não afetam os rendimentos de carcaça, coxa, sobrecoxa, asa, tulipa, moela coração fígado, proventrículo e intestino. Entretanto, a gordura abdominal aumenta e o rendimento de peito decresce proporcionalmente à elevação da energia da dieta em ambiente de altas temperaturas.

Efeitos da temperatura e da movimentação do ar sobre o isolamento térmico do velo de ovinos em câmara climática

Foram utilizados dez ovinos da raça Corriedale - cinco machos e cinco fêmeas com pesos entre 52,2 e 87,6 kg - com o objetivo de avaliar o efeito da combinação da movimentação do ar (0 e 5,0 m/s) com a temperatura do ar (25, 30 e 40ºC) sobre a temperatura retal (T R, ºC), da epiderme (T E, ºC), da superfície do velo (T V, ºC) e do interior do velo (T I, ºC) e a espessura do velo (E V, cm) e suas relações com o isolamento térmico do velo. A presença de vento não teve efeito sobre as variáveis estudadas, o que sugere que fluxo de ar (<5,0 m/s) paralelo ao eixo corporal do animal tem pouco efeito sobre o isolamento térmico do velo, independentemente da temperatura do ar, que se mostrou altamente correlacionada, de forma positiva, com as temperaturas retal, do velo, do interior do velo e da epiderme. Sob temperaturas inferiores a 30ºC, a transferência de calor através do velo ocorreu via condução e convecção livre, enquanto sob altas temperaturas (>40ºC) o fluxo de calor sensível não foi significativa.

Concentrações plasmáticas de cortisol, hormônios tiroídeanos, metabólitos lipídicos e temperatura corporal de cabras alpinas submetidas ao estresse térmico

The objective of this work was to determine the plasma concentrations of cortisol, thyroid hormone, lipids metabolites and corporal temperature or lactating Alpine goats submitted to heat stress. Six lactating Alpine goats were allotted randomly in a crossover experimental design for two groups: thermoneutral conditions or thermal stress. An adaptation period of 28 days was followed by Four-periods of 14 days each, when the animals submitted to thermal stress were exposed to the average temperature of 33.84 degrees C; THI of 86.20; BGT of 36.18 and BT of 32.11 degrees C from 8:00 am to 5:00 pm, including simulated solar radiation from 10:00 am to 3:00 pm. There were no differences between the groups in the plasma concentrations of cortisol, thyroid hormones (T-3-triiodothyronine and T-(4) tiroxine), and lipid metabolites (cholesterol and HDL). Rectal temperature was higher during thermal stress when compared to the group of animals in thermoneutral conditions. The goats maintained the thyroid plasma hormone concentrations, when exposed to repealed and intermittent stress, in spite of the occurrence of hypertermia during heat stress.

Modelagem da variação horária da temperatura do ar em Petrolina, PE, e Botucatu, SP

The air temperature is a climatic element of interest for several agricultural related studies. Hence, daily air temperature from two locations in Brazil (Botucatu and Petrolina, with different climate classification), hourly recorded from January 2004 to December 2005, were analysed to verify if 24 h long air temperature variation can be predicted with 6 h interval records. Three data set were selected, with different first time record of air temperature, and analyses performed using geoestatistics to confirm the temporal dependency of records. Then, ordinary krigging was used to model air temperature variation within 1 h interval, and spherical model presented the best approach, with range of 11.6 h for Botucatu and 12.7 for Petrolina. For both locations, the time of air temperature recording was the most importnat factor on accuracy of estimation of air temperature variation. Records at 2, 8, 14 and 20 h and at 4, 10, 16 and 22 h presented the best approaches, but for records at 9, 15 and 21 h, the approach was worst.

Rugosidade superficial de ligas com alto conteúdo de cobre, em função do aquecimento acima da temperatura de fusão.

Being the surface roughness a fundamental property in the fit of the castings, it was determined the roughness of 5 high-copper casting alloys, according to the heating over their melting temperature. That way, the specimens made with smooth plastic in the shape of a rectangular plate, 2 mm x 7 mm x 11 mm were invested into a cristobalite investment. After heating and elimination on the plastic, the molds were filled by 3 g of molten alloy, casted in a electrical casting machine at the casting temperature at 25 degrees C and 50 degrees C overheating. The surface roughness was measured in a roughness analyser, Talysurf. As a result, it was verified that there is a variation of surface roughness among the alloys tested, and the heating of the alloys until 50 degrees C over the melting temperature does not interfere in the roughness.

Efeito da temperatura sobre o desenvolvimento de Scymnus (Pullus) argentinicus (Coleoptera: Coccinellidae)

The biology of Scymnus (Pullus) argentinicus Weise on Schizaphis graminum at the temperatures 20, 25 and 30°C was studied. The temperatures of 25 and 30°C were favorable to S. (Pullus) argentinicus development. The average of the incubation period was 3.24 days and the larval development was 8.43 days at 25°C. The duration of the instars and pre-pupal and pupal periods was significantly shorter at 25 and 30°C. The percentage of emerging adults was higher at 30°C (98%) while at 20°C this percentual was 82%.

Efeito da restrição alimentar inicial e da temperatura ambiente sobre o desenvolvimento de vísceras e ganho compensatório em frangos de corte

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da relação entre a temperatura da superficie corporal e produção de vacas jersey submetidas à climatização na pré-ordenha

Jersey cows has been used in warm climates because they have better performance in dairy production. Generally milk production is reduced in warm climates due to the consequent reduction in feed intake because of the heat stress. When the heat stress occurs there is an increase in the body temperature, however it is not known if the skin temperature indicates a thermal discomfort or if it influences milk yield. The objective of this research was to verify if there was a correlation between skin temperature and milk yield using two treatments. Treatment (A) where the cows stayed for 30 minutes before the milking period, in a room with a shower and a fan; and treatment (B) where the cows did not had access to any cooling device (control). After milking the skin temperature were recorded in the places: forehead, back, leg and teats. Data were statistically analyzed and, even though in treatment (A) the skin temperature were reduced it was not found correlation between skin temperature and milk yield.

Extração de matéria orgânica aquática por abaixamento de temperatura: Uma metodologia alternativa para manter a identidade da amostra

In this work was developed an alternative methodology to separation of aquatic organic matter (AOM) present in natural river waters. The process is based in temperature decreasing of the aqueous sample under controlled conditions that provoke the freezing of the sample and separation of the dark extract, not frozen and rich in organic matter. The results showed that speed of temperature decreasing exerts strongly influence in relative recovery of organic carbon, enrichment and time separation of the organic matter present in water samples. Elemental composition, infrared spectra and thermal analysis results showed that the alternative methodology is less aggressive possible in the attempt of maintaining the integrity of the sample.

Amônia (NH3) atmosférica: Fontes, transformação, sorvedouros e métodos de análise

Ammonia is the most common alkaline gas of the atmosphere, being important in the neutralization of various processes that occur in the atmosphere. Its main sources of emission are the decomposition of organic matter and dejections of animals. Ammonia is used by man in diverse activities of production, therefore it is a gas that can contaminate work environments. Measurements of ammonia concentration in some parts of the world have shown great spatial and weather variation. This large variability makes it difficult to estimate the input of reduced nitrogen to different ecosystems from measurements.

Efeito da temperatura ambiente e da restrição alimentar protéica ou energética sobre o ganho de peso e crescimento ósseo de frangos de corte

The effect of protein or energy restriction during the second week post-hatching on body weight gain and femur development of broiler chickens reared at different environmental temperatures (18°C, 25°C and 33°C) was studied. From 1 to 7 days of age and after a restriction period broilers were fed on a control diet with 2850 kcal ME/kg and 20% crude protein. From 8 to 14 days of age, two groups of broilers were fed on restricted energy and protein diets with 2565kcal ME/kg and 20% of crude protein or 2850kcal ME/kg and 15% of crude protein, respectively. At 14, 21, 28, 35 and 42 days, the bones were weighed and the length and width of bones measured. The protein restriction reduced the body weight gain and the diameter of bone at second week of life. After 21 days of age no differences between treatments for these traits were observed. The body weight gain and femur growth were not affected by energy restriction. The high temperature (33°C) reduced weight gain and femur diameter from 21 to 42 days of age, and femur length at 42 days of age. The protein restriction at second week or the high environmental temperature after 21 st day of life decreased body weight gain and femur growth of broiler chickens.

Efeito da temperatura na germina̧ão de sementes de Sebastiania commersoniana (Baillon) Smith & Downs separadas pela colora̧ão do tegumento

Sebastiania commersoniana (Euphorbiaceae) is a tree species of riparian forests in Brazil. Seeds of this species released from mature fruits have heteromorphy in coat colour: dark (dark-brown to black), striated (dark with light-grey stria) and clear (light-grey to whitish). In this work two experiments were carried out in order to study the effect of temperature on seed germination in interaction with coat colour. Germination final percentage and speed index were evaluated. In the first experiment seeds of the three colours were submitted to constant (30°C) and alternating (20-35°C) temperatures. For all the seed colours, best results were obtained at alternating temperature. Physiological quality of striated seeds was greater than those clear seeds and dark seeds were intermediate. In the second experiment striated and clear seeds were submitted to three amplitudes of alternating temperature: 5°C (20-25°C and 25-30°C), 10°C (20-30°C and 25-35°C) and 15°C (20-35°C). Both germination percentage and speed were higher in striated seeds and for the two seed colours, best results were obtained at 20-30°C and 20-35°C. These temperatures are recommended for the germination test.

Temperatura ambiente e concentrações séricas de cortisol em suínos em crescimento-terminação

Thirty-six castrated males and females Landrace x Large-White pigs (74 to 149 days of age) were randomly allotted to two environmental conditions: high temperature in a climatic chamber (HT; 22.2 to 32.8 °C) and comfort temperature in a conventional shed (CT; 17.6 to 26.6 °C), with night-and-day variations. Blood samples were weekly collected from animals of both HT and CT conditions for determination of serum cortisol levels. Cortisol levels of both sexes were not different, and there was no interaction with environmental temperature. Pigs of HT showed significantly higher average cortisol level (P<0.01) than the CT ones (7.06 and 4.82 mg/dL, respectively). Increasing in serum cortisol was continuous and linear (P<0.05) during the experimental period, suggesting the cortisol as a possible indicator of the heat stress in growing-finishing pigs.

Contaminación atmosférica y conciencia ciudadana

En el conjunto de textos reunidos en este libro se exponen los propósitos y resultados del proyecto "Fortalecimiento de la conciencia ciudadana para la formulación de políticas de control de la contaminación atmosférica en tres metrópolis de América Latina", ejecutado por la División de Desarrollo Sostenible y Asentamientos Humanos de la CEPAL, con el auspicio del Gobierno de Japón, en el período 2000-2002. El proyecto se centró en un aspecto crucial para el éxito de los planes de descontaminación atmosférica: la conciencia ciudadana con respecto a la problemática ambiental; en este caso específico, la contaminación del aire. En este contexto, cabe preguntarnos: ¿qué valor le asignamos a la conciencia ciudadana con relación a este problema? ¿Se trata acaso de una simple convicción que nos lleva a adoptar estilos de vida acordes con la protección del medio ambiente o estamos ante un fenómeno más complejo, como la comprensión de las causas y efectos del problema, para promover la participación del ciudadano en la toma de decisiones sobre las acciones a desarrollar para el logro de una calidad atmosférica socialmente aceptable? La conciencia ciudadana resulta imprescindible para promover dicha participación y asegurar así el éxito de las políticas de protección del medio ambiente. El libro se divide en dos partes: la primera, a su vez, agrupa dos estudios, uno de ellos referido a la conciencia ciudadana necesaria para promover la descontaminación atmosférica y la acción proactiva de los ciudadanos, y otro sobre los nexos entre participación, ciudadanía y contaminación. En la segunda parte del libro se presentan los resultados y las conclusiones del proyecto realizado en las ciudades de México, D.F., Santiago de Chile y São Paulo. El primer capítulo contiene un análisis sobre las teorías referidas a la revolución de los problemas ambientales desde la perspectiva de las ciencias sociales y la importancia de una mayor participación ciudadana como complemento de la formulación tradicional de políticas de protección del medio ambiente. El segundo capítulo ahonda en la reflexión sobre la participación en torno a la aplicación de políticas relativas a la contaminación del aire en América Latina, cuyos temas articuladores son la participación popular en la gestión pública y las transformaciones cualitativas en la relación Estado/sociedad civil, que aparecen como puntos de inflexión en el fortalecimiento de las políticas públicas. En la segunda parte se presentan los tres casos de estudio realizados en México, D.F., Santiago de Chile y São Paulo, sus resultados y conclusiones y las direcciones futuras. Estas tres ciudades seleccionadas figuran entre las más particularmente afectadas de la región en cuanto a la calidad de su atmósfera. En la ejecución del proyecto ha resultado claro que en ninguna de estas ciudades existe un grado de conciencia ciudadana que supere los niveles básicos de sensibilización y que se está muy lejos de lograr un comportamiento proactivo en materia de protección del medio ambiente. Parece incuestionable la necesidad de involucrar a la ciudadanía en cciones destinadas a limitar la circulación de vehículos, pero, por otra parte, es necesaria su participación en procesos de toma de decisiones que lleven a las autoridades a desempeñar efectivamente las funciones que les competen y que no asumen, por falta de presión ciudadana. En esta última conclusión está implícita la necesidad de perfeccionar la democracia a través de un mayor protagonismo de la ciudadanía, para superar los límites del modelo representativo que en muchos casos ha hecho crisis en la región.