Description of the Responses of Some Blood Constituents to Rodeo Exercise in Chilean Creole Horses

The aim of this study was to assess the effect of the Chilean rodeo exercise on some blood constituents, classically used to assess welfare, during rest; training with and without steer; and before and after official competitions. During the training season, 13 horses were assessed at their farms of origins, and samples were taken at rest and after training with and without a steer; then during the competition season, 16 horses were assessed at four different times, one before and three after the competition. The blood constituents assessed were packed cell volume (PCV), total proteins, fibrinogen, cortisol, neutrophil:lymphocyte ratio, creatine phosphokinase, aspartate transaminase, glutathione peroxidase, and serum amyloid A. Analysis of variance for repeated measures was applied using the Statistix 8.0 software, and a significance level of P <.05 was applied. For horses assessed during exercise with and without a steer, significant differences were observed for PCV, which were significantly lower at rest than after both exercises, and total proteins, which showed a significant increase only after exercise with steer. In the case of official competitions, PCV was significantly higher immediately after rodeo, and the lowest value for cortisol was observed the evening after competition (P <.05); among the enzymes assessed, creatine phosphokinase plasma concentrations immediately after rodeo and the evening after competition were significantly higher than concentrations the next morning. The use of physiological indicators did not seem to be sufficient to assess the overall effect of rodeo on the welfare of these horses, and other types of indicators should be considered in future studies. (C) 2013 Elsevier Inc. All rights reserved.