Effect of shearing and environmental conditions on physiological mechanisms in ewes.

The aim of this study was to establish the influence of shearing in dairy sheep during summer season. Several physiological and haematological parameters, which are closely related to thermoregulatory potential, have been investigated with the purpose to assess shearing influence on thermoregulation. Forty dairy sheep, clinically healthy and well-fed, were used. They were divided into two groups of 20 subjects each. Twenty sheep were let unshorn as a control group (Group A), and twenty sheep were shorn (Group B). On each subject of group A and Group B, rectal temperature, respiration and heart rates were recorded and blood samples were collected in order to asses the following parameters: red blood cells, white blood cells, platelets, haematocrit and haemoglobin. All measurements taken on day 0 (before shearing), were repeated after 1, 15, 30, 45 and 60 days after shearing. The statistical analysis, the ANOVA followed by the Bonferroni's test, showed statistical differences between two groups for rectal temperature (F(1.90) = 5.57, p < 0.0001), respiratory rate (F(1.90) = 18.40, p < 0. 0001) and white blood cells (F(1.190) = 7.61, p < 0.0001). These results suggest that the shearing induce adaptative responses in the organism.