Influence of shearing on the circadian rhythm of body temperature in the sheep.

The presence of functional rhythmic variations is a well-demonstrated phenomenon at all levels of physiological organization and especially in the functioning of the cell components, of tissues and of organic systems. In domestic animals, the body temperature presents spontaneous and regular periodic oscillations over different periods of time, which are the result of complex mechanisms that witness the existence of endogenous and exogenous factors. Taking this knowledge as a starting-point, the authors studied 12 Comisana breed ewes to observe the influence of shearing on the circadian periodicity of rectal and skin temperature. The obtained results show the transient loss of body temperature rhythm by shearing, with an exogenous component, the shearing itself, and an endogenous component, the modifications of metabolic levels induced by the removal of the fleece, the external insulating layer.