2015 ACVIM Forum Research Abstract Program

The possibility that plasma hormone variations could be objective biomarkers of fatigue to exercise was tested by monitoring Iberian show horses (22 geldings and 15 stallions, 11 AE 4 years; bodyweight = 481 AE 34 kg, BCS = 2.8 AE 0.2) during a work season. Plasma adrenocorticotropic hormone (ACTH), cortisol, free thyroxine (FT 4 ), testosterone, prolactin, insulin-like factor-I (IGF-I), insulin and leptin concentrations were assessed monthly. The workload intensity score was determined according to exercise data and grouped into four categories: W 1 to W 4 . Repeated-measures ANOVA with post hoc Bonferroni's test were used to evaluate the effects of workload on plasma hormone concentrations and body condition parameters.