Uso do sistema de resfriamento adiabático evaporativo no conforto térmico de vacas da raça girolando

Almeida, Gledson Luiz Pontes de; Pandorfi, Héliton; Guiselini, Cristiane; Henrique, Hugo Manoel

doi:10.1590/s1415-43662011000700015

Cited by 15 publications

(7 citation statements)

References 18 publications

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“…This result indicates that the higher the enthalpy, the lower the expected RR. This theory appears to be false because an enthalpy system, utilizing the amount of heat referred above, by kilogram of dry air, shows positive correlation with RR as a consequence of increased animal discomfort (DE ALMEIDA et al, 2011). For this reason, enthalpy was eliminated from the equation to grant greater reliability to the model.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of thermorregulatory capacity of dairy buffaloes using infrared thermography

2016

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ABSTRACT:The objective of this study was to evaluate the thermoregulatory response of dairy buffaloes in pre-milking and post-milking. To identify animal thermoregulatory capacity, skin surface temperatures were taken by an infrared thermometer (SST), a thermographic camera (MTBP) as well as respiratory rate records (RR). Black Globe and Humidity Index (BGHI), radiating thermal load (RTL) and enthalpy (H) were used to characterize the thermal environment. Artificial Neural Networks analyzed those indices as well as animal physiological data, using a single layer trained with the least mean square (LMS) algorithm. The results indicated that pre-milking and post-milking environments reached BGHI, RR, SST and MTBP values above thermal neutrality zone for buffaloes. In addition, limits of surface skin temperatures were mostly influenced by changing ambient conditions to the detriment of respiratory rates. It follows that buffaloes are sensitive to environmental changes and their skin temperatures are the best indicators of thermal comfort in relation to respiratory rate.KEYWORDS: buffalo, heat stress, respiratory rate, surface temperature. AVALIAÇÃO DA CAPACIDADE TERMORREGULATÓRIA DE BÚFALAS LEITEIRAS UTILIZANDO TERMOGRAFIA DE INFRAVERMELHORESUMO: O objetivo deste trabalho foi avaliar a resposta termorregulatória de búfalas leiteiras nos ambientes de pré-ordenha (sala de espera) e pós-ordenha. Para identificar a capacidade termorregulatória dos animais, coletou-se a temperatura de superfície da pele, utilizando um termômetro de infravermelho (TMPT) e uma câmera termográfica (TMPC), e a frequência respiratória (FR) dos animais. Para a caracterização do ambiente térmico, foram calculados o índice de temperatura de globo e umidade (ITGU), a carga térmica radiante (CTR) e a entalpia (H). Os índices e os dados fisiológicos dos animais foram analisados utilizando-se de Redes Neurais Artificiais com uma única camada, treinadas com o algoritmo mínimo quadrado médio (LMS -Least mean square). Os resultados indicaram que os ambientes de pré e pós-ordenha alcançaram valores de ITGU, FR, TMPT e TMPC acima dos limites relacionados à zona de termoneutralidade dos bubalinos, sendo a temperatura superficial da pele influenciada mais intensamente pela variação das condições ambientais em detrimento da frequência respiratória. Conclui-se que os bubalinos são sensíveis às variações ambientais, sendo o s valores de temperatura de superfície da pele melhores indicadores de conforto térmico em relação à frequência respiratória.

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Section: Resultsmentioning

confidence: 99%

Evaluation of thermorregulatory capacity of dairy buffaloes using infrared thermography

2016

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“…De acordo com Almeida et al (2011), uma vez que o resfriamento evaporativo implica em redução da temperatura do ar com consequente aumento da sua umidade relativa, pressupõe-se que este sistema seja mais eficiente em regiões de clima quente e seco, como é o caso da região em estudo.…”

Section: Figura 1 Médias E Desvio Padrão Da Temperatura De Bulbo Secunclassified

Comportamento, produção e qualidade do leite de vacas Holandês-Gir com climatização no curral

Almeida

Pandorfi

Barbosa

et al. 2013

Rev. bras. eng. agríc. ambient.

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RESUMOObjetivou-se, com este trabalho, avaliar o tempo de exposição dos animais ao sistema de resfriamento adiabático evaporativo no curral de espera sobre as variáveis meteorológicas (temperatura e umidade relativa do ar), comportamento animal, produção e aspectos qualitativos do leite de vacas Girolando, utilizando-se 16 vacas multíparas de composição genética 7/8 Holandês-Gir em lactação, com produção média de 18 kg de leite animal. O delineamento experimental utilizado foi o quadrado latino 4 × 4. O experimento teve duração de 56 dias, realizado durante o período de verão. Os tratamentos corresponderam aos intervalos de 10, 20 e 30 min de exposição à climatização e controle, sendo que o tempo de 30 min de exposição ao sistema possibilitou condicionamento térmico na segunda ordenha (turno da tarde), proporcionando aumento na produção de leite na ordenha seguinte de 0,640 kg animal -1 . Verificou-se maior percentual de tempo despendido com a ingestão de alimentos e ruminação (17,31 e 30,19%) no tratamento 30 min, comparativamente ao controle (15,50 e 27,37%), respectivamente. Não se verificou efeito significativo na composição do leite, entre os tratamentos. Palavras-chave: bem-estar animal, bovinocultura de leite, conforto térmico animalBehavior, production and milk quality of Holstein-Gir cows under acclimatization in the corral ABSTRACT This study was conducted with the objective to evaluate the duration of exposure of animals to the evaporative cooling system in the waiting barn on the weather variables (temperature and relative humidity), animal behavior, production and quality aspects of milk from Girolando cows. Sixteen multiparous lactating cows were used having a genetic composition of 7/8 Holstein-Gir and mean milk production of 18 kg animal -1 day -1 . A 4 x 4 Latin square design was used. The experiment was conducted during the summer season (February-March 2009) and lasted 56 days. The treatments consisted of different periods of 10, 20 and 30 minutes of exposure to acclimatization and control. Time of 30 minutes of exposure to thermal conditioning system enabled the second milking (evening shift), providing an increase in milk production in the next milking of 0.640 kg animal -1 . A higher percentage of time spent on food intake and rumination (17.31 and 30.19%) in 30 minutes treatment, compared to control (15.50 and 27.37%), respectively. There was no significant effect of treatments in the composition of milk.

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“…Stressful environmental conditions become a limiting factor for animal production in the tropics as the thermal environment has a direct effect on the efficiency of the production system, as well as on animal health and welfare (Paim et al, 2013). The optimal ambient temperature for dairy production depends on the species, breed, age, feed intake, acclimatization, yield levels, hair and coat characteristics, as well as the animal tolerance to heat and cold (Almeida et al, 2011). Establishing an economically viable system in a given region requires the choice of breeds or varieties that are suited to local environmental conditions (McManus et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Infrared thermography as a method for evaluating the heat tolerance in dairy cows

et al. 2017

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-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.

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Uso do sistema de resfriamento adiabático evaporativo no conforto térmico de vacas da raça girolando

Cited by 15 publications

References 18 publications

Evaluation of thermorregulatory capacity of dairy buffaloes using infrared thermography

Evaluation of thermorregulatory capacity of dairy buffaloes using infrared thermography

Comportamento, produção e qualidade do leite de vacas Holandês-Gir com climatização no curral

Infrared thermography as a method for evaluating the heat tolerance in dairy cows

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