A comparison of surface and rectal temperatures between sheared and non-sheared alpacas (Lama pacos)

The objective of this research was to determine if whole-body shearing would effect gross thermoregulation in alpacas. Eight mature, intact male alpacas were randomly assigned to one of two groups and maintained in outdoor pastures with adequate artificial shade from June through August (summer climate) in east central Alabama, USA. Group one animals (N=4) were sheared to remove all fiber to within 2cm of their skin. Group 2 animals (N=4) were left non-sheared. Sheared alpacas tended to have lower rectal temperatures during high ambient temperatures than did non-sheared alpacas (P=0.06). Thermographic studies of the scrotum revealed cooler surface temperatures in sheared versus non-sheared alpacas (P=0.05). Temperatures in the right medial thigh of sheared animals were 0.9 degrees C cooler than the thigh region of non-sheared animals in the morning (P<0.03). Right medial thigh temperatures were 1.6 degrees C cooler in sheared alpacas in the afternoon (P<0.01). Significant positive correlations were found in non-sheared animals between ambient temperature and rectal temperature in the morning (r=0.612, P=0.014). In sheared animals during the morning significant positive correlations were established between the Heat Stress Index (HSI) and the right medial thigh surface temperatures (r=0.648, P=0.003), the HSI and rectal temperature (r=0.729, P=0.0003), the ambient temperature and right medial thigh surface temperature (r=0.485, P=0.04), and the ambient temperature and the rectal temperature (r=0.823, P<0.0001). In the afternoon a significant positive correlation was found in the sheared alpacas between the HSI and the right medial thigh surface temperature, rectal temperature and surface scrotal temperature (r=0.538, P=0.02, r=0.543, P=0.019 and r=0.522, P=0.045), respectively. These data indicate that whole-body shearing of alpacas could have a beneficial effect on thermoregulation when used as a preventative measure against heat stress. Shearing may assist heat dissipation resulting in a cooler surface body temperature and rectal temperature in alpacas when challenged by the heat and humidity experienced in the summer months in the southeastern United States.