Thayla Morandi Ridolfi de Carvalho

Noise analysis to evaluate chick thermal comfort

The relationship between thermal environment and chick performance has widely been evaluated, however the consideration that the assessment of the comfort may be estimated by interpreting both amplitude and frequency of bird vocalization under tropical housing conditions is a new concept. This research had as objective of estimating thermal comfort for chicks during the heating phase using this new concept. An experiment was carried out inside a climate controlled chamber (A) for establishing the behavioral pattern related to environmental temperature limits. Forty five chicks were reared inside a 2.3 m2 box. A video camera was placed 2.0 m above the birds and the images were captured and registered in a computer. From the pattern determined in the controlled chamber an evaluation of the results was proceeded in a commercial broiler farm (experiment B) using similar bird density in order to validate the data. Environmental temperature, and both amplitude and frequency of the vocalizations of the chick group reared under heating were continuously recorded in both experiments. A correlation between group behavioral pattern and their vocalization, was found, evaluated not only by the noise amplitude but also by the noise frequency spectrum. When the thermal inertia is maintained by adequate use of curtains the birds vocalized less which is coincident with the low sudden variation of the temperature of the environmental. It was possible to estimate the thermal comfort for chicks at the heating stage by recording the amplitude and the frequency of the noise emitted by the reared group.

Strategies and facilities in order to improve animal welfare

To keep the position in being a world-wide exporter of chicken meat, Brazil must meet international quality standards, always seeking alternative resources of improvement, without increasing production costs, including litter quality, requirements of animal welfare and environment affairs, such as the use and reuse of broiler litter. Researches are performed in the areas of animal welfare, environment, animal behavior and use of modern climatization technology improving the quality of the environment created to raise broilers, also trying to reduce the greenhouse gas emissions and global warming in the environment, becoming a sustainable production system. This paper has a bibliographic revision of the subject mentioned above, intending to show a state-of-art key factors related to a new concept of broiler environment and welfare.Para manter a posicao de maior exportador de carne de frango, o Brasil deve se adequar as exigencias internacionais dos padroes de qualidade, procurando sempre recursos alternativos de melhoria, sem grande incremento no custo de producao, incluindo a qualidade da cama, requisitos de bem-estar animal e as questoes ambientais, como o uso e a reutilizacao das camas de frango. Para isso sao necessarias pesquisas nas areas de bem-estar animal, ambiencia, comportamento animal e uso de tecnologias de climatizacao modernas que aperfeicoem a qualidade do ambiente gerado para criacao dos frangos, visando, alem deste fator, menor emissao de gases com potencial efeito estufa para o ambiente, tornando-se um sistema de producao sustentavel. De acordo com o exposto, realizou-se uma ampla revisao bibliografica deste assunto, buscando mostrar o estado da arte dos principais fatores relacionados aos novos conceitos de ambiencia e bem-estar de frangos de corte.

Qualidade da cama e do ar em diferentes condições de alojamento de frangos de corte

The objective of this work was to assess the initial conditions of poultry housing for one-day-old chicks regarding the quality of reused bedding and of the air in commercial broiler houses with different types of minimum ventilation and typology, using geostatistical analysis. The experiment was carried out in four broiler houses: Blue House I (T1) and Blue House II (T2), Dark House (T3), and Conventional (T4). The following variables were evaluated: pH, moisture, surface temperature, and ammonia concentration, and samples were collected at bird height at 80 equidistant points in the brooding areas. Geostatistical analysis helped to identify the environmental critical control points. The management of minimum ventilation is not sufficient to guarantee air quality in the brooding area. The reused coffee and rice husk beds (T1 and T2) show better quality than the reused wood shaving beds (T3 and T4). The minimum ventilation system, in T2 and T4, is the most efficient regarding air renovation inside the brooding areas.

Ammonia emissions in tunnel-ventilated broiler houses

Gas production in broiler houses and their emissions are closely related to the microclimate established inside the house according to air temperature, humidity, and velocity. Therefore, the internal house environment is influenced by building typology and ventilation system. The objective of the present study was to evaluate ammonia emission rates in broiler houses equipped with different ventilation systems (negative or positive pressure) and litter conditions (new or built-up). The environment of six commercial broiler houses was evaluated internal and external NH 3 concentrations. Ventilation rates were recorded to estimate ammonia emission rates. The efficiency of circulation and exhaust fans was assessed, and higher ventilation rates were determined in negative-pressure houses due to the higher flow of the fans. Houses with new litter increased ammonia emission rates along the rearing period, indicating the relationship between gas emissions, bird age and ventilation rates, and presented a typical curve of NH 3 emission increase. Negative-pressure houses with built-up litter presented higher emission rates during the first rearing week due to the high NH 3 concentration during the brooding period, when the ventilation rates required to maintain chick thermal comfort are low. Although the results of the present study indicate an advantage of the positive-pressure systems as to gas emissions, further research is needed reduce gas emissions in broiler houses with negative-pressure systems.

Use of geostatistics on broiler production for evaluation of different minimum ventilation systems during brooding phase

The objective of this research was to evaluate different minimum ventilation systems, in relation to air quality and thermal comfort using geostatistics in brooding phase. The minimum ventilation systems were: Blue House I: exhaust fans + curtain management (end of the building); Blue House II: exhaust fans + side curtain management; and Dark House: exhaust fans + flag. The climate variables evaluated were: dry bulb temperature, relative humidity, air velocity, carbon dioxide and ammonia concentration, during winter time, at 9 a.m., in 80 equidistant points in brooding area. Data were evaluated by geostatistic technique. The results indicate that Wider broiler houses (above 15.0 m width) present the greatest ammonia and humidity concentration. Blue House II present the best results in relation to air quality. However, none of the studied broiler houses present an ideal thermal comfort.

Efeito do resfriamento evaporativo e do balanço eletrolítico sobre a lactação de porcas em condições de verão tropical

O experimento foi realizado em uma granja comercial com 72 femeas suinas da genetica DanBred(r) e objetivou avaliar os efeitos do resfriamento evaporativo e do balanco eletrolitico sobre o desempenho e os parâmetros de termorregulacao de porcas lactantes no verao. O delineamento experimental foi blocos ao acaso com quatro tratamentos em disposicao fatorial 2 x 2 e 18 repeticoes por tratamento. Os tratamentos foram dois sistemas de ventilacao (ventilacao natural ou resfriamento evaporativo) e duas dietas (balanco eletrolitico de 175mEqkg-1 ou balanco eletrolitico alto de 275mEqkg-1). Os valores medios encontrados para temperatura ambiente e umidade relativa do ar foram de 24,8oC e 64,5%, respectivamente, sendo obtidos valores diarios de 31,6°C para a temperatura ambiente maxima e de 19,8°C para a temperatura ambiente minima. Nao houve efeito (P>0,05) significativo do resfriamento evaporativo e do balanco eletrolitico sobre o consumo de racao, a condicao corporal e o intervalo desmame-estro das porcas. O sistema de resfriamento evaporativo proporcionou reducao (P<0,05) na frequencia respiratoria e temperatura superficial mensuradas nos periodos da manha e da tarde e na temperatura retal a tarde e aumento (P<0,10) no peso dos leitoes ao desmame. A dieta com balanco eletrolitico alto nao influenciou essas variaveis. Concluiu-se que a utilizacao do sistema de resfriamento evaporativo contribuiu para reduzir os efeitos do calor sobre as variaveis relacionadas a termorregulacao das porcas em lactacao durante o verao e proporcionou aumento no peso dos leitoes ao desmame. Em dieta com niveis nutricionais especificos para climas quentes, o balanco eletrolitico alto nao minimizou os efeitos do estresse calorico.

The impact of evaporative cooling on the thermoregulation and sensible heat loss of sows during farrowing

Em comparacao com outras especies de animais de criacao comercial, os suinos sao mais sensiveis a temperatura ambiente elevada, pois sao incapazes de suar, e a respiracao ofegante nao e eficiente. O sistema de resfriamento evaporativo pode favorecer o conforto termico dos animais durante a exposicao a altas temperaturas e reduzir os efeitos prejudiciais do estresse termico. Objetivou-se com este estudo avaliar a troca de calor sensivel e os parâmetros de termorregulacao de porcas em lactacao submetidas a dois sistemas de climatizacao: natural e resfriamento evaporativo, durante o verao. O experimento foi conduzido em uma granja comercial com 72 porcas em lactacao, no qual foram monitoradas as variaveis ambientais (temperatura, umidade relativa do ar e velocidade do ar), os parâmetros fisiologicos das porcas (temperatura retal, temperatura superficial e frequencia respiratoria) e, assim, foi calculada a troca de calor sensivel no periodo de 21 dias de lactacao. Os resultados nao indicaram efeito significativo dos sistemas de climatizacao sobre a temperatura retal. Porem, o resfriamento evaporativo proporcionou reducao significativa na temperatura superficial e na frequencia respiratoria, alem do aumento significativo na troca de calor sensivel das porcas. A utilizacao do resfriamento evaporativo contribuiu para aumentar a perda de calor sensivel, e, portanto, este sistema pode amenizar os efeitos negativos do calor na termorregulacao das porcas lactantes durante o verao.

Heat transfer to calculate minimum ventilation rates for broilers house.

The correct use of minimum ventilation and heating system on broiler’s brooding phase is important even in tropical climates such as Brazil. Thus, the study of heat exchange is important to determine new materials of insulation for the walls and roof, in order to achieve optimal levels of thermal comfort to raise the birds. The objective of this study was to evaluate the actual minimum ventilation rate compared to the ideal ventilation rate calculated throw the heat balance of the brooding area from a tunnel ventilated broiler house totally closed with black side curtains and to improve the minimum ventilation and the heating systems to reach the ideal temperature inside the brooding area. The trail was performed at Mombuca city, State of Sao Paulo. The broiler house had a brooding area that was divided in 80 grids to collect the climatic variables (dry bulb temperature, relative humidity and air velocity) at the birds’ level and inside and outside the broiler house and the CO2 concentration was collected only inside the brooding area. The inside and outside surface temperature of all the brooding area (curtains, ceiling and roof) was collected using a thermograph camera. All data were collected 4 times a day (9AM, 2PM, 5PM and 9PM), in winter-time. The minimum ventilation rate was calculated according the methodology proposed by Albright (1990). The temperature was always below the ideal temperature according Nicholson et al. 2004 demonstrating the need of a 58Kg of diesel/day to reach the birds ideal temperature.

Different light intensity on the behavior and welfare of commercial broiler chicks.

In Brazil, the use of buildings with negative pressure system is increasing. The influence of different colors of side curtains on bird’s behavior is unknown. Depending on the curtain’s color its causes more or less luminosity inside the building, especially because the birds are photosensitivity. The luminosity has direct influence on the incidence of leg problems, and the UV rays may prevent it. This research aimed to evaluate the use of different curtain’s colors of broiler houses with negative pressure system with an emphasis in behavior and the incidence of leg problems. Three poultry farms located in Tiete / SP and Cerquilho / SP were studied, where treatment T1 was a negative pressure broiler house with black curtain, treatment T2 negative pressure broiler house with blue curtain and treatment T3 negative pressure broiler house with yellow curtain. Environmental data, animal behavior and the incidence of leg problems were monitored, during 3 flocks. Also, variable “Comfort TA” was created to evaluate the environmental conditions of the studied broiler houses. It was found a significant difference in bird’s behavior between treatments and some of them were related to luminosity. There was no relation between the incidence of leg problems with the light intensity and ultraviolet rays. The behavior of birds was influenced by the environmental variables.

Study of Statistical Methods in the Spatial Variability Measurement of Climatic Variables within Broiler Houses

Natural ventilation is important for bird welfare in Brazilian poultry housing, increasing the heat loss by convective ways. The objective of this research was to analyze the feasibility of geostatistical methodology in estimating the spatial pattern of climatic variables within broiler houses. Dry-bulb temperature (DBT, °C), relative humidity (RU, %), light intensity (L, lux), and air velocity (V, m/s) were collected in the middle of 72 cells in two similar broiler houses located at Tuiuti city, state of Sao Paulo, Brazil. A portable thermoanemometer (Extech® Model 45160) was used to collect the temperature, relative humidity, and air velocity data. To measure the light intensity, a luximeter (Hagner®) was used. The temperature, humidity and air velocity index, THIV, was calculated with the climatic data. The software MatLab® was used to perform the statistical analysis. The software SURFER® 1995 was used to build the maps of climatic variables. The results showed that the statistical technique allows finding some areas within the houses with different spatial variability on all studied climatic variables. The values show an asymmetrical distribution for the variables of light intensity, air velocity, and THIV. The statistical analysis showed a spatial dependence of the climatic variables on both broiler houses. Therefore, it can be concluded that the homogeneity was observed for the climatic variables from the relative humidity and wind velocity in the broiler house with the use of tunnel ventilation. The light intensity was more homogeneous in the tunnel ventilation compared to the natural ventilation.