Navegando por Assunto "thermal comfort"
Agora exibindo 1 - 6 de 6
Resultados por página
Opções de Ordenação
Item BEHAVIOR OF BROILERS UNDER THE INFLUENCE OF LED LIGHTING AND MICROMETEOROLOGICAL ELEMENTS(2020) Rodrigues, Tatiana P. N. da S.; Pandorfi, Héliton; Guiselini, Cristiane; Almeida, Gledson L. P. de; Morrill, Waldirene B. B.ABSTRACT The objective of this research was to analyze the differences between the food behaviors observed under the factors of production environment, sex and lighting system, using stochastic tools of multivariate analysis. As for the thermal characteristics of the environment, air temperature (T, °C), enthalpy (H, kJ kg-1), and black globe temperature and humidity index (BGTHI) showed high positive correlation with each other and strong negative correlation with relative humidity (RH, %). The “male drinking” behavior was positively associated with thermal characteristics of the environment in the three periods of the day, that is, the act of drinking more water would be a way to alleviate thermal stress. Birds subjected to red LED showed a strong negative correlation with temperature associated with the “female drinking” behavior, in the afternoon period, according to the principal component analysis, which is justified by the orientation of the broiler house with its longitudinal axis in the NE/SW direction, so the sunlight directly hits the area where the drinker was located. Variation in body weight showed better response when the birds were exposed to a temperature of 27 °C, for the 5th week of the rearing cycle.Item Behavior of pigs subjected to climate control system in the Semi-arid Region of Pernambuco, Brazil(2021) Gomes, Nicoly Farias; Pandorfi, Héliton; Barnabé, Janice Maria Coelho; Guiselini, Cristiane; Almeida, Gledson Luiz Pontes de; Holanda, Mônica Calixto Ribeiro de; Holanda, Marco Aurélio Carneiro de; Silva, Marcos Vinícius daAbstract The objective was to thermally characterize the facilities during the growth and finishing phases of pigs and to evaluate the influence of climate control systems on the expression of the behaviors of pigs. The experiment was conducted at the Federal Rural University of Pernambuco, Serra Talhada, PE, Brazil, during the spring of 2019. Twenty-seven pigs aged 63 days were used. The animals were submitted to pens without climate control system, with forced ventilation, and with an evaporative adiabatic cooling system. Dry bulb temperature (°C), relative air humidity (%), black globe temperature (°C), and swine behavioral responses were recorded, submitted to multivariate analysis, using the principal component technique. Pens with the evaporative adiabatic cooling system showed a significant reduction in air temperature and an increase in relative air humidity, during the two phases. Pigs submitted to evaporative cooling showed greater ingestive activity and lethargic behavior, typical of the studied phases. Resumen El objetivo fue caracterizar térmicamente las instalaciones durante las fases de crecimiento y finalización de los cerdos y evaluar la influencia de los sistemas de control climático en la expresión de los comportamientos de los cerdos. El experimento se realizó en la Universidad Federal Rural de Pernambuco, Serra Talhada, PE, Brasil, durante la primavera de 2019. Se utilizaron 27 cerdos de 63 días. Los animales fueron sometidos a corrales sin sistema de climatización, con ventilación forzada y con sistema de enfriamiento adiabático evaporativo. Se registraron la temperatura de bulbo seco (° C), la humedad relativa del aire (%), la temperatura del globo negro (° C) y las respuestas de comportamiento de los cerdos, sometidas a análisis multivariante, utilizando la técnica de componentes principales. Los corrales con sistema de enfriamiento adiabático evaporativo mostraron una reducción significativa de la temperatura del aire y un aumento de la humedad relativa del aire, durante las dos fases. Los cerdos sometidos a enfriamiento evaporativo mostraron mayor actividad ingestiva y comportamiento letárgico, propio de las fases estudiadas.Item Infrared thermography as a method for evaluating the heat tolerance in dairy cows(2017) Daltro, Darlene dos Santos; Fischer, Vivian; Alfonzo, Evelyn Priscila München; Dalcin, Vanessa Calderaro; Stumpf, Marcelo Tempel; Kolling, Giovani Jacob; Silva, Marcos Vinícius Gualberto Barbosa da; McManus, ConceptaABSTRACT The objective of this study was to determine whether infrared thermography is a useful tool for the recognition of dairy cows in a state of thermal heat stress, as well as to identify the best region of the animal to be evaluated for this recognition. Physiological variables, including rectal temperature, respiratory frequency, cardiac frequency, and panting score were recorded in 38 lactating cows. For the assessment of environmental parameters, a digital black globe thermometer (TGD-200 model) was used. Thermographic photographs of different regions of the body of cows were taken using an infrared camera (FLIR® System T300) and indicated respective superficial temperature. Physiological variables and superficial body temperature in different regions varied between genetic groups (Girolando: ½ Holstein × ½ Gir and ¾ Holstein × ¼ Gir; purebred Holstein). The environmental temperature ranged from 20.7 to 37.9 °C with a relative humidity reaching 95%. The mean rectal temperature (40.84 °C), respiratory frequency (111.36 breaths/min), and cardiac frequency (99.22 beats/min) were higher for pure Holstein than for Girolando cows. Positive correlations were found between the physiological parameters and thermographic measures. The highest positive correlation (0.74) was found between the temperature in the lateral region of the udder and rectal temperature. Thermography is a good indicator of thermal comfort. The best region to identify heat stress in cows using thermography is the lateral region of the udder.Item PERFORMANCE AND WELFARE OF FINISHING PIGS SUBJECTED TO CLIMATECONTROLLED ENVIRONMENTS AND SUPPLEMENTARY LIGHTING(2020) Barnabé, Janice M. C.; Pandorfi, Héliton; Gomes, Nicoly F.; Ameida, Gledson L. P. de; Guiselini, CristianeABSTRACT An adequate thermal environment in pig farming facilities is essential to ensure productivity and animal welfare. The objective of this study was to evaluate the behavior and performance of finishing pigs, subjected to climate-controlled environments and supplementary lighting. Twenty-seven pigs (3/4 Duroc, 1/4 Pietrain) were kept in pens with no climate control, pens with forced ventilation and pens with adiabatic evaporative cooling system, associated with 12 h of natural light, 12 h of natural light + 4 h of artificial light and 12 h of natural light + 6 h of artificial light. The experimental design was completely randomized, in a 3x3 factorial arrangement and the means were compared by Tukey test (p<0.05). Meteorological variables, temperature and relative humidity, were recorded and the zootechnical performance of the animals was evaluated by weight gain, feed intake and feed conversion. Behavioral analysis was performed using the frequency of ingestive and comfort behaviors (exploratory activities and social interactions). Better performance was found for animals subjected to evaporative cooling, and the program with supplementary lighting for 6 hours promoted better feed conversion. Pigs subjected to evaporative cooling showed higher frequency of comfort behaviors and higher frequency of ingestive activity, stimulated by better thermal conditions in the housing.Item Physiological parameters for thermal stress in dairy cattle(2016) Dalcin, Vanessa Calderaro; Fischer, Vivian; Daltro, Darlene dos Santos; Alfonzo, Evelyn Priscila München; Stumpf, Marcelo Tempel; Kolling, Giovani Jacob; Silva, Marcos Vinícius Gualberto Barbosa da; McManus, ConceptaABSTRACT The objective of this study was to investigate changes in physiological parameters of dairy cows and understand which physiological parameters show greater reliability for verification of heat stress. Blood samples were collected for analysis and included hematocrit (Ht), erythrocyte count (ERY), and hemoglobin count (HEMO). In addition, physiological variables, including rectal temperature (RT), heart rate (HR), respiratory rate (RR), and panting score (PS) were recorded in 38 lactating cows. These varied according to genetic group (1/2, 3/4, and pure bred Holstein (HO)). Analysis of variance considering the effects of genetic group, days, and their interaction as well as linear and quadratic effect of the black globe humidity index (BGHI) was performed, as well as broken-line regression. These values were higher in pure HO than in 3/4 and 1/2 groups. The average BGHI during the morning was 74, when 70, 43, and 13% of pure HO, 3/4, and 1/2, respectively, presented RR above reference value. The RR was the best indicator of heat stress and its critical value was 116 breaths/min for 1/2, 140 for 3/4, and 168 breaths/min for pure HO cows. In the HO group, physiological variables increased linearly with BGHI, without presenting inflection in the regression. The inflection point occurred at a higher BGHI for the 1/2 group compared with the other groups. Hematocrit and HEMO were different among genetic groups and did not vary with BGHI, showing that stress was not sufficient to alter these hematological parameters. The 1/2 HO group was capable of maintaining normal physiological parameters for at least 3 BGHI units above that of HO and 1 to 3 units higher than 3/4 HO for RR and RT, respectively. Respiratory rate is the physiological parameter that best predicts heat stress in dairy cattle, and the 1/2 Holstein group is the best adapted to heat stress.Item Physiological parameters for thermal stress in dairy cattle(2016) Dalcin, Vanessa Calderaro; Fischer, Vivian; Daltro, Darlene dos Santos; Alfonzo, Evelyn Priscila München; Stumpf, Marcelo Tempel; Kolling, Giovani Jacob; Silva, Marcos Vinícius Gualberto Barbosa da; McManus, ConceptaABSTRACT The objective of this study was to investigate changes in physiological parameters of dairy cows and understand which physiological parameters show greater reliability for verification of heat stress. Blood samples were collected for analysis and included hematocrit (Ht), erythrocyte count (ERY), and hemoglobin count (HEMO). In addition, physiological variables, including rectal temperature (RT), heart rate (HR), respiratory rate (RR), and panting score (PS) were recorded in 38 lactating cows. These varied according to genetic group (1/2, 3/4, and pure bred Holstein (HO)). Analysis of variance considering the effects of genetic group, days, and their interaction as well as linear and quadratic effect of the black globe humidity index (BGHI) was performed, as well as broken-line regression. These values were higher in pure HO than in 3/4 and 1/2 groups. The average BGHI during the morning was 74, when 70, 43, and 13% of pure HO, 3/4, and 1/2, respectively, presented RR above reference value. The RR was the best indicator of heat stress and its critical value was 116 breaths/min for 1/2, 140 for 3/4, and 168 breaths/min for pure HO cows. In the HO group, physiological variables increased linearly with BGHI, without presenting inflection in the regression. The inflection point occurred at a higher BGHI for the 1/2 group compared with the other groups. Hematocrit and HEMO were different among genetic groups and did not vary with BGHI, showing that stress was not sufficient to alter these hematological parameters. The 1/2 HO group was capable of maintaining normal physiological parameters for at least 3 BGHI units above that of HO and 1 to 3 units higher than 3/4 HO for RR and RT, respectively. Respiratory rate is the physiological parameter that best predicts heat stress in dairy cattle, and the 1/2 Holstein group is the best adapted to heat stress.