Educação no Século XXI - Volume 15 - Ciências e Biologia

Thermal comfort indexes and physiological parameters of Santa Inês and crossbreed ewes in the semi-arid

“…It was observed that there was a significant difference (P <0.01) in sheep heart rate between the shifts (Table 3), with the highest values in the afternoon, similar to those reported by Oliveira et al (2005) and Andrade et al ( 2007), which describe values of lower heart rate in the morning in relation to the afternoon shift. Among the pure and crossbreed animals, a significant difference (P <0.01) was observed, with the lowest values for Santa Inês in the two shifts, and this reduction may be associated to the greater adaptability of these animals to the climate of the semi-arid region.…”

“…The fact that the indoor temperature environment is lower than the external environment demonstrates the importance of the shading promoted by the coverage of the confinement facility. This is confirmed by Andrade et al (2007) and Oliveira et al (2013) when evaluating the physiological parameters of Santa Inês sheep subjected to shading and exposed to the grazing sun. They concluded that shading provided a reduction in all physiological variables analyzed, mainly in the afternoon, when the environmental conditions were more unfavorable for the animals.…”

“…Eustáquio Filho et al (2011) in sheep research observed a significant linear effect on the fur temperature, which increased with increasing environment temperature, and as it increases, the efficiency of the losses of sensible heat decreased due to the lower temperature gradient between the animal's skin and that of the environment. Andrade et al (2007) in experiments with Santa Inês sheep in the semi-arid region of Paraíba, mentions that thermal comfort indexes were higher in the afternoon, which resulted in higher rectal, superficial, respiratory and cardiac temperature in the animals.…”

“…In the Brazilian semi-arid all year round, and especially in the dry season occur high temperatures (Rocha et al 2014), associated with the low relative humidity of the air and the small air movement, and according to Silva (2000) in hot and dry environment occurs evaporation rapidly, causing dermal irritation and general dehydration and in hot and humid environment, evaporation processes slowly, reducing thermolysis and increasing heat stress, mainly because the convolution thermolysis is ineffective when the temperature differential between body surface and the atmosphere. Animals under thermal stress may be limited in development, production and reproduction, also affecting their physiological variables (Oliveira et al 2005;Andrade et al 2007 andEustáquio Filho et al 2011).…”