ABSTRACT The objective of this study was to characterize the thermal environment and evaluate the behavior of finishing pigs housed in deep bedding and conventional systems. The work was carried out in the Department of Animal Science of the Federal Institute of Education, Science and Technology of Southeast Minas Gerais, Rio Pomba campus. Three pens were used in an installation for breeding pigs in their finishing phase. Two pens contained deep bedding, with wood shavings and rice husks. The remaining pen was a conventional system. The behavior of the piglets was observed from 8 a.m. to 5:30 p.m., noting the behaviors with the use of an ethogram, while data relating to the thermal environment in the stalls were automatically collected using data loggers. Thermal environment data for all systems presented thermal stress conditions. Regarding behavioral variables, animals in conventional systems had a higher frequency of visits to feeders, while animals in the deep bedding system were more active and visited the drinking fountains more frequently. Despite the higher level of activity of the animals in the deep bedding system, it is not possible to confirm that the deep bedding provides a better degree of well-being for the animals under thermal stress conditions.

ABSTRACT Although dry bulb temperature (T) is the environmental variable most commonly used to classify thermal comfort in pigs, environmental assessment ratios provide more accurate information. The objective of this study was to correlate the sound pressure levels (SPL) produced by piglet vocalization with the thermal environment observed during the nursery phase, and subsequently establish thermoneutrality ranges. The experiment was conducted on a pig farm where T, relative humidity (RH), and SPL data were recorded between 9 am-5 pm for 42 days. The association between SPL and T in nursery phase piglets was verified; for thermal comfort to be possible, SPLs were 56.3 to 60.3 dB. The SPLs were subsequently used in predictor equations of ratios, and thermal comfort ranges were 74.4-78.3 for temperature and humidity ratio (THI), and 71.6-75.8 for globe temperature and humidity ratio (BGHI). Although the SPL proved to be a convenient indicator of thermal comfort for the evaluation of pigs, further studies developed in different phases of the production system are required.

RESUMO O objetivo do presente trabalho foi estabelecer o zoneamento bioclimático por meio do índice de temperatura e umidade (ITU), considerando-se um período histórico e um cenário futuro, de forma a representar o ambiente térmico para criação de frangos de corte no estado de Minas Gerais. Foi utilizada uma série histórica (1976 - 2014) de ITU mínimo, médio e máximo, que foram calculados com base em dados oriundos de 48 estações meteorológicas convencionais, pertencentes ao Instituto Nacional de Meteorologia do Estado de Minas Gerais. A análise da série temporal se baseou no teste de Mann-Kendall e na regressão linear. Procedeu-se, também, à análise geoestatística para determinação do zoneamento do conforto de frangos de corte segundo os intervalos de ITU. Dessa forma, as metodologias de mapeamento espacial do ITU e a análise de tendência para predição de um possível cenário climático futuro podem auxiliar no desenvolvimento de mapas de risco para o monitoramento do conforto térmico de frangos de corte, sendo indispensáveis no planejamento de ações para mitigação dos impactos das mudanças climáticas sobre a cadeia produtiva do estado de Minas Gerais.

ABSTRACT The objective of the present study was to establish the bioclimatic zoning by the temperature and humidity index (THI), considering a historical period and a future scenario, in order to represent the thermal environment for broiler breeding in the State of Minas Gerais. A historical series (1976 - 2014) of THI minimum, average and maximum calculated based on data from 48 conventional meteorological stations was used, belonging to the National Institute of Meteorology of the State of Minas Gerais. The analysis of the temporal series was based on the Mann-Kendall test and linear regression. A geostatistical analysis was also carried out to determine the comfort zoning of broilers as a function of the THI intervals. In this way, the THI spatial mapping methodologies and trend analysis for the prediction of a possible future climate scenario can help in the development of risk maps for monitoring thermal comfort of broilers, being indispensable in the planning of actions for the mitigation of the climatic change impacts on the productive chain of the State of Minas Gerais.

ABSTRACT The selection of the type of fuzzy systems pertinence curve allows a better representation of the mathematical model and a smaller simulation error. We aimed to study the effect of pertinence curves in fuzzy modeling of broiler performance, created in different production systems. For the development and testing of fuzzy models, three commercial aviaries (conventional, tunnel with negative pressure, and dark house) were evaluated over one year, totaling six lots per system. For the development of the model, the input variables were enthalpy in each rearing phase (initial: phases 1, 2, and 3; growth: phase 4; and final: phase 5) and the output variables were feed intake (FE), weight gain (GP), feed conversion (FE), and the productive efficiency index (PEI). Triangular, trapezoidal, and Gaussian pertinence curves were combined and applied to represent the input and output fuzzy sets, totaling nine fuzzy models for each output variable. The combinations of pertinence curves provided adequate responses for the prediction of AL, GP, RC, and PEI. However, the selection of the types of curves should be studied on a case-by-case basis, so that the smallest possible simulation errors are obtained.

ABSTRACT Broiler chickens are classified as homoeothermic animals and require a production environment within well-defined thermal comfort intervals. Therefore, the development of algorithms (mathematical models) to control the environment that can be embedded in microcontrollers becomes necessary. Hence, this work aimed to develop a fuzzy model for predicting the productive performance of broiler chickens as a function of the thermal environment during the various breeding phases. The Mamdani inference and defuzzification methods were used, by means of the gravity center, to develop the fuzzy model. Two hundred and forty-three rules with weighting factors of 1.0 each were elaborated. Three commercial warehouses (conventional system, wind tunnel with negative pressure and dark house) were evaluated for testing of the model. We recorded the thermal environment (dry bulb temperature - tdb and relative humidity - RH) and productivity data (feed intake - FI, weight gain - WG, feed conversion - FC and productive efficiency index - PEI) over six lots in each aviary. The resulting fuzzy model was capable of forecasting FI, WG, FC, and PEI, with standard deviations and mean percentage errors of 4.16 g and 5.05%, 146.53 g and 8.04%, 0.06 g g−1 and 4.96%, and 24.51 g and 12.29%, respectively.

ABSTRACT Broiler chickens submitted to different intensities and durations of thermal stress are subject to variation in cloacal temperature and, consequently, to a decrease in performance. Given the complexity of these interactions, artificial intelligence is a useful methodology for decision-making. Thus, this study aimed to assess and predict, by means of a fuzzy model, the cloacal temperature of broiler chickens submitted to thermal stress in the second week of life, with varying durations and intensities, in climatized wind tunnels. Mamdani's inference and defuzzification methods by means of the center of gravity were used. One hundred and twenty rules were elaborated. The developed fuzzy model was used to predict the cloacal temperature of broiler chickens on the day of thermal stress as a function of air dry-bulb temperature (°C), stress duration (days), and the number of days after thermal stress. Cloacal temperature values simulated by the fuzzy model showed standard deviations and percentage errors lower than 0.02 and 0.08%, respectively, when compared to those obtained experimentally.

ABSTRACT Broiler chickens are homoeothermic animals, i.e., animals capable of maintaining their body temperature within quite narrow limits; therefore, climate change poses a great challenge to poultry. With this in mind, this research aims to evaluate the performance of broilers submitted to different commercial production systems and exposed to different future scenarios, taking into account the climate change trends. To achieve this objective, we developed and validated a fuzzy model able to predict the performance of a broiler as a function of enthalpy along its life stages. This model was developed and validated in part I of this article based on experimental data collected for one year in three aviaries: conventional, negative pressure, and dark house systems. A Mann-Kendall nonparametric test and linear regression analysis were applied to the enthalpy values, which were calculated as a function of the ambient air temperature and relative humidity in order to study the climate change trends. Later, simulations were performed using the fuzzy model for 2025, 2050, 2075, and 2100 future scenarios. Specific improvements were observed when the heating trends coincided with the initial stages of breeding; however, in general, the productive responses of broilers in the different evaluated systems worsened with the climate change trends. Faced with the climate change trends, the responses improved in the order dark house aviary > negative pressure aviary> conventional aviary.

ABSTRACT This study aimed to compare fuzzy systems with different configurations to predict the surface temperature (ts) of broiler chickens subjected to different intensities and durations of thermal challenges in the second week of life. Data on the ts of broiler chickens aged 8 to 11 days were acquired by infrared thermography and subjected to combinations of four dry-bulb temperatures (tdb) (24, 27, 30, and 33 °C) and four durations of thermal challenges (DTC) (1, 2, 3, or 4 days). The input variables of the fuzzy systems were tdb and DTC, and the output variable was ts. The Mamdani inference method involving five defuzzification methods [center of gravity (centroid), bisector of the area (bisector), largest of maximum (lom), middle of maximum (mom), and smallest of maximum (som)], and Sugeno inference with two defuzzification methods [weighted average (wtaver) and weighted sum (wtsum)] were evaluated. For both inference methods, triangular and Gaussian pertinence functions were tested for input and output variables, except for Sugeno inference, which used singletons functions as output variables. While developing fuzzy systems, different configurations must be compared, and the system with smaller simulation errors should be selected.

RESUMO Uma interessante maneira de se mensurar a eficiência de sistemas produtivos é por meio da análise energética, identificando quais insumos ou operações demandam mais energia. Portanto, objetivou-se no presente trabalho avaliar a eficiência energética de um sistema de criação de frangos de corte, confinados em galpões com tipologia Darkhouse. Foram considerados os fluxos de energia referentes a um ciclo completo de produção, 56 dias, onde foram computadas as entradas e saídas de energia, na forma direta e indireta, por meio da estimação da energia presente na ração, água, máquinas e equipamentos, trabalho humano, galpões, silos, dentre outros que compõem o sistema produtivo, multiplicando-se pelos seus respectivos coeficientes energéticos. Foram encontradas a demanda total de energia pelo sistema em um ciclo de produção, a energia necessária para produção de 1 kg de frango vivo e o coeficiente de eficiência energética do mesmo. O sistema estudado apresentou um coeficiente de conversão da energia de 46%, valor próximo ao encontrado para sistemas de produção animal. Foram necessários, em média, 37,55 MJ kg-1 de frango vivo. O principal ponto estrangulador do sistema correspondeu à energia consumida na forma de ração, com 75% do total da energia direta.

ABSTRACT The objective of this study was to evaluate the sustainability of a broiler chicken production system, with confinement in Darkhouse sheds, by energetic analysis. Energy flows of a complete production cycle, 56 days, were considered, of which the energy inputs and outputs were computed in direct and indirect forms, by estimating the energy coming from the quantity of feed, water, machinery and equipment, human labor, sheds, silos, among other components of the productive system, multiplied by their respective energetic coefficients. The total energy demand of a system in a production cycle for the production of 1 kg of live chicken and its energy efficiency coefficient were determined. The studied system had energy conversion coefficient of 95%, demonstrating that the production model has high energy conversion efficiency and fits a sustainable model. On average, 37.55 MJ kg-1 of live chicken were necessary. The main limiting point of the system corresponded to the energy consumed in the form of feed, with 75% of the total direct energy.

Abstract The aim of the present research was to propose a bioclimatic mapping to classify the thermal comfort and discomfort of rural workers within the state of Minas Gerais, considering historical and future scenarios. Monthly historical series (1976-2014) of minimum, mean and maximum temperature-humidity index (THI), determined through the values of air temperature (minimum, mean and maximum) and relative humidity from 48 weather stations located in the state of Minas Gerais were used to analyze the trends through Mann-Kendall and linear regression assays. The bioclimatic mapping of human comfort, obtained via geostatistical analysis, was developed as a function of the minimum, medium and maximum THI for the historical period (1976-2014) and future scenario (2024). Results indicate an overall trend of increasing in thermal discomfort conditions throughout the mesoregions of the state of Minas Gerais during the weather seasons, being more incisive in summer and spring.

ABSTRACT: The cloacal and surface temperatures are important physiological parameters to quantify the thermal comfort of animals, its variations may occur as a function of thermal variables. In this context, the goal of the present study was to evaluate the cloacal (tclo) and surface (tsur) temperatures of Cobb 500® broilers, in the second week of life, subjected to different air dry-bulb temperature (24, 27, 30 and 33 °C) and stress durations (1, 2, 3 and 4 days). The experiment was carried out in four climate-controlled wind tunnels. Air relative humidity and air velocity were set at 60% and 0.2 m s-1, respectively. The tclo and tsur were measured daily through digital thermometer and thermographic camera, respectively. Analysis of variance and Scott Knott mean test at 5% probability were applied to the data. The results indicate that the stress by low air temperature (24 and 27 °C) resulted decreased of tclo and tsur (p<0.05, Scott-Knott test). When subjected to high air temperature stress (33 °C), there was no significant difference (p>0.05, Scott-Knott test) compared to the control treatment (30 °C). Acclimation of broilers to thermal stress occurred from the second day of stress.

RESUMO O objetivo do trabalho foi avaliar a concentração de gases em três instalações de crescimento e terminação para suínos, com tipologias construtivas diferentes no que tange ao piso e divisórias. Compararam-se três tratamentos: baia com lâmina d’água, baia com piso parcialmente vazado nas laterais e baia com piso parcialmente vazado nas laterais e no centro. Foram feitas medições das concentrações instantâneas de amônia (NH3, ppm) e dióxido de carbono (CO2, ppm) a nível dos animais; também foram registrados os níveis de pressão sonora (dB) a nível dos animais e a 1,50 do piso. Observou-se que a baia com lâmina d’água foi a que apresentou o maior valor médio de concentração de NH3. Apesar de haver ocorrido diferenças significativas nas concentrações de CO2, os valores encontrados estão dentro dos limites permitidos pelas normas brasileiras, presumindo-se, assim, que as instalações não ocasionam desconforto em relação aos níveis de CO2. A baia com lâmina d’água demostrou proporcionar um possível desconforto aos animais, com nível de concentração de NH3 acima de valores que já podem acarretar problemas aos animais de acordo com o preconizado pela literatura. Não foi observada influência do tipo de piso da baia sobre a pressão sonora em nenhum horário.

ABSTRACT The objective of this study was to evaluate the concentration of gases in three swine growing and finishing facilities with different building typologies, regarding floor and dividers. The experiment compared three treatments: pen with water depth, pen with partially slotted floor on the sides, and pen with partially slotted floor on sides and in the center. Measurements of instantaneous concentrations of ammonia (NH3 ppm) and carbon dioxide (CO2 ppm) were taken at animal level. The levels of sound pressure (dB) at animal level and at 1.50 m from the floor were also recorded. It was observed that the pen with water depth was the one with the highest average concentration of NH3. Although there was a significant difference in CO2 concentrations, the observed values are within the limits allowed by the Brazilian standards; thus, it is assumed that the facilities do not cause discomfort in relation to CO2 levels. The pen with water depth possibly caused discomfort to the animals, since the NH3 concentration was above the values that can cause problems to the animals, according to the recommendation of the literature. There was no influence of the type of pen on the sound pressure at any time.

ABSTRACT The aim of this study was to develop an automated fuzzy controller with microcontroller, consisting of hardware and software for the control and supervision of thermal environment in broiler farms. The study has been conducted in two steps: in the first one it was performed a computer analysis through simulation. In the second step it was performed the evaluation of the software and hardware developed by the equipment test in the registration of the thermal environment variables within the facility and activation of the climate control equipment. The experiment was conducted in a poultry house with broilers of Cobb 500 lineage, aged between 1 and 28 days in an experimental farm located in Bambuí - MG. The presented prototype is able to operate in an automatic way, the equipment control for the ambience in poultry farms and supervision of meteorological variables. The developed fuzzy controller estimated satisfactorily the thermal comfort for the poultry during 28 days of experiment, keeping the thermal parameters within the specified by literature. The system can be used in the automation of ambience equipment for the four steps of the production chain for broiler chickens.

RESUMO Dentro de um galpão avícola o ambiente térmico exerce grande influência sobre o bem-estar e a produtividade dos animais, ao longo do ciclo de produção. A entalpia é uma propriedade termodinâmica que tem sido proposta para avaliação do ambiente interno de galpões de criação de frangos de corte por ser um indicador da quantidade de energia contida em uma mistura de vapor d'água e ar seco razão por que se objetivou, com o presente trabalho, caracterizar a variabilidade espacial da entalpia em um galpão de frangos durante a fase de aquecimento de pintinhos utilizando a geoestatística. O experimento foi conduzido na primavera, em um galpão comercial com sistema de aquecimento constituído de duas fornalhas de aquecimento indireto do ar, durante os primeiros 14 dias de vida das aves. Utilizando as técnicas da geoestatística foi possível caracterizar a magnitude da variabilidade espacial da entalpia permitindo a observação da dependência espacial por meio de mapas de krigagem. A análise dos mapas permitiu observar a existência de falhas no sistema de aquecimento em regiões do galpão, que podem ser possíveis causadoras de desconforto térmico para os animais, além de perdas produtivas e econômicas.

ABSTRACT The thermal environment inside a broiler house has a great influence on animal welfare and productivity during the production phase. Enthalpy is a thermodynamic property that has been proposed to evaluate the internal broiler house environment, for being an indicator of the amount of energy contained in a mixture of water vapor and dry air. Therefore, this study aimed to characterize the spatial variability of enthalpy in a broiler house during the heating phase using geostatistics. The experiment was conducted in the spring season, in a commercial broiler house with heating system consisting of two furnaces that heat the air indirectly, in the first 14 days of the birds' life. It was possible to characterize enthalpy variability using geostatistical techniques, which allowed observing the spatial dependence through kriging maps. The analyses of the maps allowed observing problems in the heating system in regions inside the broiler house, which may cause a thermal discomfort to the animals besides productive and economic losses.

RESUMO Diante da necessidade de se obter sistemas, para melhor controlar o ambiente de produção de frangos de corte, foi realizado um experimento com frangos de corte de 1 a 21 dias, os quais foram submetidos a diferentes intensidades e durações de temperaturas do ar em túneis de vento climatizados, e os resultados foram utilizados para a validação de um modelo fuzzy. O modelo foi desenvolvido, utilizando como variáveis de entrada: duração do estresse térmico (dias), temperatura de bulbo seco do ar (°C) e, como variável de saída: consumo de ração (g), ganho de peso (g) e conversão alimentar (g.g-1). O método de inferência utilizado foi o de Mamdani, tendo sido elaboradas 20 regras, e a técnica de defuzzificação usada foi a do Centro de Gravidade. Nos resultados, obtidos na simulação do modelo, quando comparados com os dados experimentais, evidencia-se uma eficiência satisfatória na determinação das respostas produtivas, nas quais os valores de R2 calculados, para consumo de ração, ganho de peso e conversão alimentar, foram de 0,998; 0,981 e 0,980, respectivamente.

ABSTRACT Given the need to obtain systems to better control broiler production environment, we performed an experiment with broilers from 1 to 21 days, which were submitted to different intensities and air temperature durations in conditioned wind tunnels and the results were used for validation of afuzzy model. The model was developed using as input variables: duration of heat stress (days), dry bulb air temperature (°C) and as output variable: feed intake (g) weight gain (g) and feed conversion (g.g-1). The inference method used was Mamdani, 20 rules have been prepared and the defuzzification technique used was the Center of Gravity. A satisfactory efficiency in determining productive responses is evidenced in the results obtained in the model simulation, when compared with the experimental data, where R2 values calculated for feed intake, weight gain and feed conversion were 0.998, 0.981 and 0.980, respectively.