title: Investigation of blood oxidant/antioxidant markers in healthy competition horses of different breeds.
abstract: BACKGROUND
  There is increasing evidence that the equine athlete is exposed to exercise-induced changes of its oxidant/antioxidant balance and antioxidant supplementation is frequently recommended. However, it is unknown whether there is a specific need for antioxidants according to performance, breed, gender or age.
  
  
  OBJECTIVE
  To assess whether breed-, gender- and age-related differences of blood oxidant/antioxidant markers occur in competition horses.
  
  
  METHODS
  Healthy horses (n = 493) underwent oxidant/ antioxidant blood marker determination. Vitamin E, lipophilic antioxidant capacity (ACL), ascorbic acid (AA), glutathione (GSH, GSSG), gluthione peroxidase (GPx), superoxide dismutase (SOD), selenium (Se), copper (Cu), zinc (Zn), lipid peroxides (Pool), oxidised proteins (Protox) were determined, as well as magnesium (Mg), creatine phosphokinase (CPK), lactate dehydrogenase (LDH), packed cell volume (PCV) and haemoglobin (Hb). A mixed linear model assessed the effect of breed, gender and age category. P<0.05 was considered significant.
  
  
  RESULTS
  Thoroughbreds showed the highest values of vitamin E, ACL, GPx, PCV and Hb, whilst standardbreds had the highest values of AA and LDH. Jumping horses had the highest Protox values. Females had significantly higher SOD values, whereas most of the other markers were higher in stallions and geldings. Horses age 2-6 years had higher AA, SOD and LDH values than horses age >6 years. Correlation analyses were positive and significant between vitamin E and GPx, VitE and ACL, Se and GPx, Cu and Pool and negative between Pool and vitamin E, Pool and ACL, Protox and GPx, Protox and vitamin E.
  
  
  CONCLUSIONS
  Blood oxidant/ antioxidant status of horses is influenced by breed, gender and age. The correlation analyses suggest synergistic relations between GPx, vitamin E and Se and an antagonistic relation between Protox-GPx, Protox-vitamin E, and Pool-vitamin E.
  
  
  CONCLUSIONS
  The results of this investigation provide definition of the specific need for antioxidants and vitamins in competition horses.
authors.affiliation: Department for Functional Sciences, Department for Animal Productions, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium.
authors.forename: N
authors.initials: N
authors.lastname: Kirschvink
authors.forename: B
authors.initials: B
authors.lastname: de Moffarts
authors.forename: F
authors.initials: F
authors.lastname: Farnir
authors.forename: J
authors.initials: J
authors.lastname: Pincemail
authors.forename: P
authors.initials: P
authors.lastname: Lekeux
mesh_terms: D000367:Age Factors; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood; D001947:Breeding; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood / Q000378:metabolism; D006736:Horses / Q000097:blood* / Q000378:metabolism; D008297:Male; D008903:Minerals / Q000097:blood* / Q000378:metabolism; D010084:Oxidation-Reduction; D012643:Selenium / Q000097:blood / Q000378:metabolism; D012737:Sex Factors; D014810:Vitamin E / Q000097:blood / Q000378:metabolism; D014815:Vitamins / Q000097:blood* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D008903:Minerals; D014815:Vitamins; D014810:Vitamin E; D005979:Glutathione Peroxidase; D012643:Selenium