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| Registros recuperados: 49 | |
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| Ferraz,Patricia Ferreira Ponciano; Yanagi Junior,Tadayuki; Hernández Julio,Yamid Fabián; Castro,Jaqueline de Oliveira; Gates,Richard Stephen; Reis,Gregory Murad; Campos,Alessandro Torres. |
| The objective of this work was to develop, validate, and compare 190 artificial intelligence-based models for predicting the body mass of chicks from 2 to 21 days of age subjected to different duration and intensities of thermal challenge. The experiment was conducted inside four climate-controlled wind tunnels using 210 chicks. A database containing 840 datasets (from 2 to 21-day-old chicks) - with the variables dry-bulb air temperature, duration of thermal stress (days), chick age (days), and the daily body mass of chicks - was used for network training, validation, and tests of models based on artificial neural networks (ANNs) and neuro-fuzzy networks (NFNs). The ANNs were most accurate in predicting the body mass of chicks from 2 to 21 days of age... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Animal welfare; Artificial neural network; Broiler; Modeling; Neuro-fuzzy network; Thermal comfort. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2014000700559 |
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| Nascimento,GR; Nääs,IA; Pereira,DF; Baracho,MS; Garcia,R. |
| This study was conducted to determine the effect of the air temperature variation on the mean surface temperature (MST) of 7- to 35-day-old broiler chickens using infrared thermometry to estimate MST, and to study surface temperature variation of the wings, head, legs, back and comb as affected by air temperature and broiler age. One hundred Cobb® broilers were used in the experiment. Starting on day 7, 10 birds were weekly selected at random, housed in an environmental chamber and reared under three distinct temperatures (18, 25 and 32 ºC) to record their thermal profile using an infrared thermal camera. The recorded images were processed to estimate MST by selecting the whole area of the bird within the picture and comparing it with the values obtained... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Image analysis; Poultry; Thermal comfort. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2011000400007 |
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| Cravo,JCM; Fiorelli,J; Lahr,FAR; Fonseca,R da; Cruz,VC da. |
| This study aimed at evaluating the thermal performance of a modular ceiling system for poultry houses. The reduced- and distorted-scale prototypes used ceiling modules made of reforested wood and were covered with recycled long-life package tiles. The following parameters were measured for 21 days: tile internal surface temperature (ST), globe temperature and humidity index (WBGT), and radiant heat load (RHL). Measurements were made at times of highest heat load (11:00 am, 13:00 pm, and 03:00 pm). Collected data were analyzed by "R" statistics software. Means were compared by multiple comparison test (Tukey) and linear regression was performed, both at 5% significance level. The results showed that the prototype with the ceiling was more efficient to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Broiler house environment; Recycled tiles; Thermal comfort. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2009000400002 |
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| Pereira,DF; do Vale,MM; Zevolli,BR; Salgado,DD. |
| Layer mortality due to heat stress is an important economic loss for the producer. The aim of this study was to determine the mortality pattern of layers reared in the region of Bastos, SP, Brazil, according to external environment and bird age. Data mining technique were used based on monthly mortality records of hens in production, 135 poultry houses, from January 2004 to August 2008. The external environment was characterized according maximum and minimum temperatures, obtained monthly at the meteorological station CATI in the city of Tupã, SP, Brazil. Mortality was classified as normal (£ 1.2%) or high (> 1.2%), considering the mortality limits mentioned in literature. Data mining technique produced a decision tree with nine levels and 23 leaves,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Data mining; Layer production; Mortality; Thermal comfort. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2010000400008 |
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| Mendes,AS; Moura,DJ; Morello,GM; Carvalho,TMR; Sikorski,RR. |
| ABSTRACT Rearing environmental conditions are important for turkey production, because this bird is particularly sensitive to heat stress. This study aimed at measuring the wattle temperature response of turkeys of three different ages (61, 96, and 131 days old) exposed to different combinations of dry bulb temperature, relative humidity, and wind speed ranges, as an indication of their physiological responses. The experiment was conducted with 42 male birds housed in a controlled environment chamber and exposed to different combinations of two air speed (WS) ranges (WS1 = 0.3-0.6 ms-1, considered low, and WS2 = 1.2-1.6 ms-1, considered high), dry bulb temperature (DBT) between 22 and 34 °C, and relative humidity (RH) between 40 to 90 %. The statistical... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Wind speed; Thermal comfort; Relative humidity; Environmental exposure. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2015000400439 |
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| Mendes,AS; Moura,DJ; Nääs,IA; Morello,GM; Carvalho,TMR; Refatti,R; Paixão,SJ. |
| This study aimed at evaluating the live performance of turkeys during the initial stage of production (1-26 days of age) and to map the environmental variables inside turkey houses, such as temperature, relative humidity, CO2 concentration, at two distinct minimum ventilation systems. House 1 (H1) was equipped with a negative-pressure ventilation system and House 2 (H2) was equipped with a positive-pressure ventilation system. This study was performed in commercial poultry houses, located in Francisco Beltrão, Paraná, Brazil, in June, 2008. A number of 14,000 turkeys toms at the same age, provided by the same local hatchery and were housed at a stocking density of 23 birds m-2. Three 13 m² boxes with 300 turkeys each were placed inside the poultry houses.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Air renewal; Gases; Poultry house; Thermal comfort. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2013000100002 |
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| Abreu,VMN; Abreu,PG de; Jaenisch,FRF; Coldebella,A; Paiva,DP de. |
| This study was conducted with the objective of evaluating the use of concrete or hard-packed dirt floor in broiler houses. This experiment was carried out in two different phases. The following performance parameters were studied: live weight, feed intake, feed conversion ratio, and mortality. Litter moisture, pH and temperature were measured. Litter residual contamination after cleaning and disinfection was also evaluated. A dry bulb thermometer, a wet bulb thermometer, and a black bulb thermometer were placed inside each broiler house at bird height and outside the broiler house for data collection. Environmental data were collected at 3h intervals from 00:00 to 24:00 hours during weeks 4, 5, and 6 of the grow-out. Based on the collected data, air... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coliforms; Litter pH; Litter temperature; Live performance; Thermal comfort. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2011000200007 |
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| Santos,MJB; Pandorfi,H; Rabello,CBV; Silva,EP; Torres,TR; Santos,PA; Morril,WB; Duarte,NM. |
| An experiment was carried out to evaluate the effect of environmental enrichment in a free-range chicken production system on live performance as a function of microclimate, physiological parameters, and performance parameters. Four production modules were divided into four pens with 10 birds each, totaling 60 birds. The following treatments were applied: access to a paddock (TEST), access to a paddock with perches (PER), access to a paddock with artificial shade (SHA), and access to the paddock with perches and artificial shade (PESH). The PESH production module presented the best globe temperature (Tbg,ºC) and enthalpy (h, kJ/kg), and thereby, the best thermal environmental conditions, which ensured the longest permanence time of the birds in the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Animal behavior; Physiological parameters; Poultry production; Thermal comfort. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2014000100003 |
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| Cunha,Gisele C. de A.; Lopes Neto,José P.; Furtado,Dermeval A.; Borges,Valéria P.; Freire,Elias A.; Nascimento,José W. B. do. |
| ABSTRACT Negative pressure ventilation in poultry houses has been used to enable the correction of their internal microclimates, and studies point to the heterogeneous distribution of air along the aviaries and the inadequacy of the environmental variables to the recommended ranges for thermal comfort of adult birds, especially in the hottest hours of the day. This study aimed to diagnose the facilities of a poultry house in the state of Paraíba, Brazil, regarding the distribution of environmental variables and thermal comfort; develop a computational model and validate it for Computational Fluid Dynamic - CFD simulations. Air temperature (Tair), air relative humidity (RH) and air velocity (Vair) data allowed characterizing the internal environment by... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Thermal comfort; Thermal index; Simulations. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662019001000761 |
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| 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,Concepta. |
| ABSTRACT 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... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Broken line; Critical values; Thermal comfort; Thermoregulation. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982016000800458 |
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| 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,Concepta. |
| ABSTRACT 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... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Animal welfare; Dairy cattle; Thermal comfort; Thermographic images. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000500374 |
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| Souza,Wander de; Barbosa,Orlando Rus; Marques,Jair de Araújo; Costa,Marco Aurélio Teixeira; Gasparino,Eliane; Limberger,Erni. |
| The aim of this work was to verify if the presence of trees and its height in formed silvipastoral systems with eucalyptus planted in rank can modify the microclimate and improve the environment for bovine raising during the day in summer. It was evaluated the microclimate of the environment in formed silvipastoral systems in rank of eucalyptus with 8 m, 18 m and 28 meters of height, compared to a system no shade in the summer. The experimental design was a split plot with six hour time in sub parcels. The systems are made up of parcels and the months as block in four replications and the interaction hour × system. The air temperature, black globe temperature, relative humidity and wind speed were observed to create the following indexes for thermal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ambient; Heat stress; Index; Shade; Thermal comfort; Trees. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010000300030 |
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| Registros recuperados: 49 | |
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