Processo de condicionamento e avaliação do equilíbrio térmico de bovinos Guzerá
Carregando...
Arquivos
Data
2016-07-12
Autores
Camerro, Leandro Zuccherato [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo deste estudo foi validar o condicionamento dos animais e o desenvolvimento de pesquisas que visem entender as respostas do equilíbrio térmico de bovinos Guzerá (Bos indicus), em consequência das variações meteorológicas ao longo do dia, em ambiente tropical e a emissão de metano. Foram avaliados dez bovinos da raça Guzerá, cinco machos e cinco fêmeas, com média de vinte meses, alojados em baias individuais, protegidos da radiação solar. A frequência respiratória, volume respiratório corrente, a produção de calor metabólico e a perda de calor latente via sistema respiratório, foram determinados usando um sistema de calorimetria indireta, com o auxílio de uma máscara facial. Simultaneamente, foram analisadas a temperatura retal (TR), temperatura da epiderme (TEP), temperatura do pelame (TS), temperatura do ar expirado (TEXP), além das variáveis meteorológicas, temperatura do ar (TA), umidade relativa (UR), radiação solar (RS), e temperatura radiante média (TRM). Também foram determinados os fluxos de calor por radiação e convecção. As temperaturas do ar expirado, do pelame e da epiderme, se mostraram dependentes da temperatura do ar, aumentando de 28 a 35°C, 31 a 38°C e 33 a 38°C, respectivamente, quando a temperatura do ar aumentou de 25 para 34°C, enquanto que a temperatura retal foi dependente da hora do dia. A produção de calor metabólico apresentou média de 115 e 155 W m-2 , para machos e fêmeas, respectivamente, e não se alterou com o aumento da temperatura do ar (25-34°C), o mesmo ocorreu para a emissão de metano e a frequência respiratória, para ambos os sexos. Este fato pode ser explicado pela capacidade de bovinos zebu estocarem calor.
The aim of this study was to validate the conditioning of animals and the development of research aimed at understanding the responses of the thermal equilibrium of Guzerá cattle (Bos indicus), as a result of weather variations throughout the day in a tropical environment and the methane emission. Evaluated ten Guzerat cattle, five males and five females, with an average of twenty months, housed in individual pens, protected from direct solar radiation. The respiratory rate, tidal respiratory volume, metabolic heat production and loss of latent heat via the respiratory system, were determined using an indirect calorimetry system with the aid of a facial mask. At the same time, we analyzed the rectal temperature (TR), skin surface temperature (TEP), hair coat temperature (TS), expired air temperature (TEXP), besides meteorological variables, air temperature (TA), relative humidity (UR) , solar radiation (RS), and mean radiant temperature (TRM). It was also determined heat flow by radiation and convection. The expired air temperature, hair coat temperature and skin surface temperature, proved to be dependent on air temperature, adding 28 to 35 ° C, 31 to 38 ° C and 33 to 38 ° C, respectively, when the air temperature increased from 25 to 34 ° C. While the rectal temperature is dependent on the time of day. The metabolic heat production averaged 115 and 155 W m-2 for males and females, respectively, and did not change with increasing air temperature (25-34 ° C), the same was true for emission of methane and respiratory rate, for both sexes. This fact can be explained by the ability of zebu cattle, heat stocked.
The aim of this study was to validate the conditioning of animals and the development of research aimed at understanding the responses of the thermal equilibrium of Guzerá cattle (Bos indicus), as a result of weather variations throughout the day in a tropical environment and the methane emission. Evaluated ten Guzerat cattle, five males and five females, with an average of twenty months, housed in individual pens, protected from direct solar radiation. The respiratory rate, tidal respiratory volume, metabolic heat production and loss of latent heat via the respiratory system, were determined using an indirect calorimetry system with the aid of a facial mask. At the same time, we analyzed the rectal temperature (TR), skin surface temperature (TEP), hair coat temperature (TS), expired air temperature (TEXP), besides meteorological variables, air temperature (TA), relative humidity (UR) , solar radiation (RS), and mean radiant temperature (TRM). It was also determined heat flow by radiation and convection. The expired air temperature, hair coat temperature and skin surface temperature, proved to be dependent on air temperature, adding 28 to 35 ° C, 31 to 38 ° C and 33 to 38 ° C, respectively, when the air temperature increased from 25 to 34 ° C. While the rectal temperature is dependent on the time of day. The metabolic heat production averaged 115 and 155 W m-2 for males and females, respectively, and did not change with increasing air temperature (25-34 ° C), the same was true for emission of methane and respiratory rate, for both sexes. This fact can be explained by the ability of zebu cattle, heat stocked.
Descrição
Palavras-chave
Calorimetria indireta, Condicionamento, Estoque térmico, Perda de calor sensível e latente, Termorregulação, Conditioning, Heat storage, Indirect calorimetry