ABSTRACT Ventilation systems are incorporated at intensive poultry farms to control environment conditions and thermal comfort of broilers. The ventilation system operates based on environmental data, particularly measured by sensors of temperature and relative humidity. Sensors are placed at different positions of the facility. Quality, number and positioning of the sensors are critical factors to achieve an efficient performance of the system. For this reason, a strategic positioning of the sensors associated to controllers could support the maintenance and management of the microclimate inside the facility. This research aims to identify the three most representative points for the positioning of sensors in order to support the ventilation system during the critical period from 12h00 to 15h00 on summer days. Temperature, relative humidity and wind speed were measured in four different tunnel ventilated barns at the final stage of the production cycle. The descriptive analysis was performed on these data. The Temperature and Humidity Index (THI) was also calculated. Then, the geostatistical analysis of THI was performed by GS+ and the position of sensors was determined by ordinary kriging. The methodology was able to detect the most representative points for the positioning of sensors in a case study (southeastern Brazil). The results suggested that this strategic positioning would help controllers to obtain a better inference of the microclimate during the studied period (the hottest microclimate), considered critical in Brazil. In addition, these results allow developing a future road map for a decision support system based on 24 h monitoring of the ventilation systems in broiler houses.
ABSTRACT This study aimed at identifying the best gender division pattern for swine at nursery stage, through the evaluation of behavioral and environmental parameters. Three treatments were established to achieve our objective: single-sex housing of 26 surgically castrated male pigs; mixed-sex housing of 13 castrated males and 13 females; and single-sex housing of 26 females. Environmental and behavioral data have been recorded. It was used an ethogram to make an inventory of behaviors and that was used in multivariate analysis. Bite addiction differed statistically among treatments, and the lowest occurrence was in mixed-sex housing. Results of the multivariate analysis suggested that regardless of the treatment chosen, relative humidity is positively associated with the production of gases and dry-bulb temperature with airspeed. Mixed-sex housing had multivariate relations suggesting less aggressive behaviors over food resources, being an example of social interaction that improves swine welfare.
ABSTRACT Using geostatistics, this study aimed to analyze environmental conditions for wean-to-finish swines at 3 pm, during the most sensitive phases to thermal stress (growth/ finishing and finishing). To this end, dry-bulb temperature, relative humidity, air speed, ammonia and carbon dioxide concentrations were measured at 81 equidistant points within the barn. Descriptive statistics was used to classify attribute variability, generating mean, median, variation coefficient, asymmetry and kurtosis, through the normality of Kolmogorov-Smirnov (KS). For that, it was used Minitab 15 software. Moreover, semivariograms were used to assess spatial dependence using the GS+ software, and through Surfer, spatial distribution maps were designed. Dry-bulb temperature and relative humidity showed a more homogeneous distribution whether compared to the other attributes. Furthermore, critical points were observed within the facility, with temperatures and low humidity, indicating the need for fogging equipment and fans to improve thermal comfort and animal welfare.
The ventilation and cooling systems are important to environmental control inside broilers house enabling the bird to express the maximum potential of production. The aim of this study was to evaluate, using geostatistical analysis, the influence of the ventilation system and the different typologies of building in relation to thermal welfare and air quality in broilers house with birds in the final phase. The broiler facilities evaluated were: Blue House - ventilation systems with exhaust fans and nebulizers, Dark House - ventilation systems with exhaust fans and pad cooling and Solid Wall - ventilation systems with exhaust fans and pad cooling. The attributes evaluated were dry bulb temperature, relative humidity, air velocity, concentration of carbon dioxide and ammonia, during the summer time at 2PM on 52 equidistant points inside the building. The data analysis was by statistical and geostatistical. Geostatistical analysis was an efficient tool to evaluate distribution of environmental conditions in the broilers houses and was able to identify the influence of presence or absence of evaporative panel inside conditions.
O sistema de ventilação e de resfriamento utilizado em instalações para frangos de corte desempenha um papel importante no controle ambiental, possibilitando que a ave expresse seu potencial máximo de produção. Nesse sentido, o objetivo deste trabalho foi avaliar, por meio da geoestatística, a influência do sistema de ventilação e das diferentes tipologias construtivas em relação ao ambiente térmico e aéreo em aviários de frangos de corte na fase final de criação. Os aviários avaliados com sistema de ventilação artificial de pressão negativa, por meio de exaustores, foram: Blue House com nebulizadores na entrada de ar e vedação de cortinas; Dark House com painel evaporativo (tijolo cerâmico) e vedação de cortinas e Solid Wall com painel evaporativo (celulose) e vedação de alvenaria. Os atributos avaliados foram: temperatura, umidade relativa, velocidade do ar, concentração de dióxido de carbono e amônia, durante o período de verão às 14h, em 52 pontos equidistantes, no interior do aviário. Os dados foram avaliados pela análise estatística e geoestatística. A análise geoestatística apresentou-se como ferramenta eficiente para a avaliação da distribuição das condições ambientais nos aviários, e a presença ou não do painel evaporativo influenciou na condição padrão de funcionamento do sistema de ventilação.
Thermal comfort is of great importance in preserving body temperature homeostasis during thermal stress conditions. Although the thermal comfort of horses has been widely studied, there is no report of its relationship with surface temperature (T S). This study aimed to assess the potential of data mining techniques as a tool to associate surface temperature with thermal comfort of horses. T S was obtained using infrared thermography image processing. Physiological and environmental variables were used to define the predicted class, which classified thermal comfort as "comfort" and "discomfort". The variables of armpit, croup, breast and groin T S of horses and the predicted classes were then subjected to a machine learning process. All variables in the dataset were considered relevant for the classification problem and the decision-tree model yielded an accuracy rate of 74 %. The feature selection methods used to reduce computational cost and simplify predictive learning decreased model accuracy to 70 %; however, the model became simpler with easily interpretable rules. For both these selection methods and for the classification using all attributes, armpit and breast T S had a higher power rating for predicting thermal comfort. Data mining techniques show promise in the discovery of new variables associated with the thermal comfort of horses.
Heat-regulation mechanisms, such as changes in peripheral blood flow, are activated by thermal stress to maintain body homeostasis. The infrared thermography enables to identify changes in blood flow and it has been valuable for recognizing stress in animals. This research aimed to evaluate the use of infrared thermography in the training horse thermoregulation. An Anglo-Arab horse was studied and exercised once a day. Infrared thermography images of horse´s armpit, croup, breast and groin and physiological parameters were taken before and after exercise and 0, 5 and 10 minutes after shower for eight days. The air temperature, relative humidity and air velocity were also registered. There were no differences between the surface temperature of croup and breast and the treatments, implying low participation in thermoregulation. However, the armpit and groin temperature increased after the exercise and decreased after shower, suggesting that vasomotor mechanisms were activated to heat exchange. Similar results were found for physiological parameters which show organism thermal responses for heat loss. It was concluded that infrared thermography allowed accuracy in determining the horse body surface temperature and it was possible to infer on thermoregulation.
O estresse térmico em equinos aciona mecanismos termorregulatórios, como mudanças no fluxo sanguíneo periférico, para a manutenção da homeostase corporal. A termografia infravermelha permite detectar estas alterações, sendo uma ferramenta útil para avaliar o estresse em animais. Assim, o objetivo deste estudo foi avaliar o uso da termografia infravermelha na termorregulação de equino em condição de treinamento. Foi utilizado um cavalo anglo-árabe, exercitado uma vez ao dia. Foram captadas imagens termográficas da axila, garupa, peito e virilha do cavalo e registrados os parâmetros fisiológicos antes e após exercício e 0; 5 e 10 minutos após o banho, durante 8 dias. A temperatura, a umidade relativa e a velocidade do ar foram monitoradas. A temperatura de superfície da garupa e do peito não diferiu entre os tratamentos, indicando baixa participação destas partes na termorregulação. Em contrapartida, a temperatura superficial da axila e da virilha aumentou após o exercício e diminuiu após o banho, sugerindo evidência dos mecanismos vasomotores para a troca térmica do cavalo. Comportamento semelhante foi observado para as variáveis fisiológicas, o que demonstra tentativas orgânicas do organismo para sair das condições de estresse térmico. Concluiu-se que a termografia infravermelha permitiu determinar com precisão a temperatura de superfície corporal do cavalo, sendo possível inferir sobre a termorregulação.
Broiler chickens in Brazil are generally reared from 1 to 42 days when they are exposed to procedures such as fasting, harvesting, crating and transport to slaughter. Maintaining homeostasis is of great importance for broiler survival under harsh environment especially prior to slaughter. Heat loss varies in the distinct parts of the body during the growth period, and it is related to the air temperature of the environment and to the amount of feather covering. This research aimed to study the surface temperature distribution using infrared thermographic image processing to characterize 42 day old broiler chicken surface temperature prior to slaughter. Broilers were reared for 42 days and prior to harvest and transport to slaughter the infrared surface temperature was recorded along the day. Data from the thermograms taken in feather and featherless regions were compared during the 42nd day of growth. High correlation between featherless regions and air temperature was found showing that these areas respond fast to changes in the rearing environment. Two functions were developed for predicting both surface temperature for featherless and feather covered areas of the broiler body parts.
No Brasil frangos de corte são normalmente alojados de 1 até 42 dias, quando são expostos a procedimentos como: jejum, apanha, colocação em caixas e transporte até o abate. Manter a homeostase do corpo é de grande importância para a sobrevivência de frangos de corte sob ambiente quente, especialmente na 7ª semana de crescimento. A perda de calor varia nas partes do corpo e está relacionada à temperatura do ar e à cobertura de penas. Avaliou-se a distribuição da temperatura superficial usando o processamento de imagens de câmera termográfica infravermelho, para caracterizar a temperatura superficial de frangos de corte de 42 dias de idade, no período anterior à apanha para o abate. Os frangos foram alojados de 1 a 42 dias e, antes de serem apanhados e transportados para o abate, foram registradas temperaturas superficiais infravermelho durante o dia.. Os resultados dos termogramas das regiões com penas e sem penas foram comparados, durante o 42º dia. Alta correlação entre regiões sem penas e a temperatura ambiente foi encontrada, mostrando que estas áreas respondem rapidamente a alterações no ambiente do alojamento. Duas funções foram desenvolvidas para predizer a temperatura superficial das regiões com e sem penas, do corpo de frangos com 42 dias, sendo conhecida a temperatura do ar do ambiente.