Quantitative buffy coat analysis related to adrenocortical function in horses during a three-day event competition.
This study was carried out to investigate stress induced in a cross-country by measuring plasma cortisol and to compare the changes in cortisol level with the leucocytic changes measured with the quantitative buffy coat (QBC) analysis, which is a new method applicable in field conditions for the evaluation of haematological parameters in horses. Seven healthy horses competing in a national three-day event were investigated. Venous blood was sampled under resting condition, 2 min and 180 min after the completion of the cross-country and analysed for haematological parameters, plasma cortisol, protein and lactate levels. Immediately after the event, there was a significant increase in all values except in the granulocytes (Gr) to lymphocytes-monocytes (LM) ratio. 180 min after the event, all the parameters returned to their resting levels while white blood cells (WBC), Gr and Gr/LM ratio were significantly higher with respect to their resting values. A high correlation (r = 0.82) was found between the relative increase in plasma cortisol levels 2 min after exercise and the relative increase in Gr/LM 180 min after exercise. Therefore it was concluded that the Gr/LM ratio measured 180 min after exercise with the QBC analysis is a reliable index to estimate the plasma cortisol levels measured 2 min after exercise. This new technique could consequently be used in order to evaluate, in field conditions, the exercise-induced stress.
Linden
A
A
Laboratory for Functional Investigation, Faculty of Veterinary Medicine, University of Liège, Belgium.
Art
T
T
Amory
H
H
Massart
A M
AM
Burvenich
C
C
Lekeux
P
P
D000302:Adrenal Cortex / Q000502:physiology*; D000818:Animals; D006098:Granulocytes; D006736:Horses / Q000097:blood*; D006854:Hydrocortisone / Q000097:blood*; D007958:Leukocyte Count / Q000662:veterinary; D008214:Lymphocytes; D009000:Monocytes; D005082:Physical Exertion / Q000502:physiology*
D006854:Hydrocortisone