Autores
Henrique Barbosa Hooper, Mara Regina Bueno de Mattos Nascimento, Daniela Santana de Oliveira, Taís Ferreira de Oliveira, Cristiane Gonçalves Titto
Body surface temperature in crossbred dairy cows on Triângulo Mineiro/Brazil climatic conditions
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 Tukey’s 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 ±
2.57°C;
29.43 ± 2.50°C;
17.54 ± 2.38°C;
and 67.18 ± 15.39%. Temperature data from body surface are presented in Table 1.
Considering seasonal climate variation in Triângulo Mineiro region, it can be
concluded that body surface temperature varies among different body regions and
was higher at body central region (withers) than in periphery (forehead, groin
and hamstring) because it is the greatest solar radiation exposure area.
Temperatura de superfície corporal em vacas leiteiras mestiças em condições climáticas do Triângulo Mineiro/Brasil
Abstract
Íntegra (PDF)