• horse;
  • stress;
  • serum;
  • superoxide-scavenging ability;
  • lipid peroxide


It has been suggested that a variety of stresses on animals may accelerate their production of superoxide. Racehorses are considered to be exposed to substantial oxide stress due to transport and exercise for training and racing. To determine the effect of exercise and transport on racehorses in terms of superoxide and antioxidative ability, changes in the superoxide-scavenging ability of equine serum were observed using electron spin resonance (ESR). Changes in the concentration of lipid peroxide, which is produced in equine serum by superoxide, were also examined.

The analysis revealed that lipid peroxide concentrations increased as a result of stress from exercise and transport. On the other hand, the superoxide-scavenging ability of equine serum showed a decline during transport, which is in sharp contrast to the increase seen immediately after a race due to the severe load exerted in exercise.