RESUMO
Cattle, when in heat stress, deflect energy to increase dissipation to environment, compromising productivity. Thus, in dairy production system it is important to maintain thermal comfort to ensure homeothermy and full performance. One of the physiological measures to evaluate thermal comfort of domestic animals is hair coat surface temperature. Knowing this temperature allows the understanding whether animal performs thermal exchanges by convection through the activation of heat dissipation latent mechanisms. This study aimed to evaluate body surface temperature in crossbred dairy cows on Triângulo Mineiro climatic conditions. This was carried out at Estação Experimental Glória of Universidade Federal de Uberlândia using 53 lactating crossbred cows. Cows were housed in shaded pen for artificial insemination and after it was performed body surface temperature mensurements. Temperature was measured from body surface at four different regions: forehead, withers, groin and hock using an Instruterm infrared thermometer model TI-890. The statistical model used the region to test the effect of surface temperature comparing means by Tukeys test, with a significance level of 5%. Means and standard deviations of ambient temperature, maximum temperature, minimum temperature and relative humidity were respectively 23.96 ± 2.57C; 29.43 ± 2.50C; 17.54 ± 2.38C; and 67.18 ± 15.39%. Temper
O artigo não apresenta resumo em português.
RESUMO
In tropical and subtropical regions animals suffer pronounced heat stress effect on reproductive function, being one of the most noticeable effects the reduction of conception rate. When evaluating animals heat stress, rectal temperature measurement is important tool because indicates heat release mechanisms became insufficient to maintain homeothermy. This study aimed to evaluate body temperature at fixed time artificial insemination of crossbred dairy cows and their conception at 30 days pregnacy. Experiment was performed from April 26, 2010 to January 28, 2012 at Estação Experimental Glória of Universidade Federal de Uberlândia, at Triângulo Mineiro, Brazil. One hundred-twelve crossbred dairy cows and heifers were used. At the moment of insemination, animals were housed in shaded pen and body temperature was collect using clinical thermometer introduced in rectal mucosa. Environmental variables collect were air temperature, maximum temperature, minimum temperature and relative humidity. Data were analyzed in two different periods: from April to September (mild weather-MW) and from October to March (hot weather-HW). The statistical model included the effect of category, period, pregnancy diagnosis and their interactions, comparing means by Tukeys test, with a significance level of 5%. Means and standard deviations of air temperature, maximum temperature, minimum temperature
ptmo em português.
RESUMO
In tropical and subtropical regions animals suffer pronounced heat stress effect on reproductive function, being one of the most noticeable effects the reduction of conception rate. When evaluating animals heat stress, rectal temperature measurement is important tool because indicates heat release mechanisms became insufficient to maintain homeothermy. This study aimed to evaluate body temperature at fixed time artificial insemination of crossbred dairy cows and their conception at 30 days pregnacy. Experiment was performed from April 26, 2010 to January 28, 2012 at Estação Experimental Glória of Universidade Federal de Uberlândia, at Triângulo Mineiro, Brazil. One hundred-twelve crossbred dairy cows and heifers were used. At the moment of insemination, animals were housed in shaded pen and body temperature was collect using clinical thermometer introduced in rectal mucosa. Environmental variables collect were air temperature, maximum temperature, minimum temperature and relative humidity. Data were analyzed in two different periods: from April to September (mild weather-MW) and from October to March (hot weather-HW). The statistical model included the effect of category, period, pregnancy diagnosis and their interactions, comparing means by Tukeys test, with a significance level of 5%. Means and standard deviations of air temperature, maximum temperature, minimum temperature
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RESUMO
Cattle, when in heat stress, deflect energy to increase dissipation to environment, compromising productivity. Thus, in dairy production system it is important to maintain thermal comfort to ensure homeothermy and full performance. One of the physiological measures to evaluate thermal comfort of domestic animals is hair coat surface temperature. Knowing this temperature allows the understanding whether animal performs thermal exchanges by convection through the activation of heat dissipation latent mechanisms. This study aimed to evaluate body surface temperature in crossbred dairy cows on Triângulo Mineiro climatic conditions. This was carried out at Estação Experimental Glória of Universidade Federal de Uberlândia using 53 lactating crossbred cows. Cows were housed in shaded pen for artificial insemination and after it was performed body surface temperature mensurements. Temperature was measured from body surface at four different regions: forehead, withers, groin and hock using an Instruterm infrared thermometer model TI-890. The statistical model used the region to test the effect of surface temperature comparing means by Tukeys test, with a significance level of 5%. Means and standard deviations of ambient temperature, maximum temperature, minimum temperature and relative humidity were respectively 23.96 ± 2.57C; 29.43 ± 2.50C; 17.54 ± 2.38C; and 67.18 ± 15.39%. Temper
O artigo não apresenta resumo em português.