The paper is available in its entirety but there's also a summary here at The Horse.
The objective of this study was to determine if competition intensity would have an effect on antioxidant status in horses before and during a three-day event. Body weight, body condition score, and blood was sampled from CCI2* (n = 19) and CCI3* (n = 23) horses before the start of dressage, 20 to 30 min following cross-country, and 18–24 h after cross-county. Data were analyzed using a PROC MIXED in SAS. There were no differences between CCI2* and CCI3* horses during competition for plasma cortisol, lactate, α-tocopherol, retinol, or erythrocyte glutathione peroxidase. After cross-country, CCI3* horses had higher serum creatine kinase (P = 0.003) and aspartate aminotransferase (P < 0.0001) than the CCI2* horses. Plasma β-carotene was higher in the CCI2* horses compared to the CCI3* horses (P = 0.0001). Total erythrocyte glutathione was also higher in the CCI2* horses versus CCI3* horses (P < 0.0001). These results are the first report of antioxidant status of horses competing in this level of a three-day event. The changes in antioxidant and muscle enzymes observed between divisions are likely due to the increased anaerobic and musculoskeletal demand on the upper level horses and the fitness required to compete at that level.
In conclusion, the cross-country jumping phase of a three-day event is a challenge to the horse's antioxidant systems, with the CCI3* competitions being a more rigorous exercise bout than the CCI2*. The increase or upregulation of markers of antioxidant status is potentially due to increased scavenging of ROS created by oxidative stress experienced by horses during intense exercise. The ROS could also cause increased muscle membrane permeability as observed by the increase in muscle enzyme concentrations in the blood. Horses that are more fit may be better able to handle the stress of a CCI3* three-day competition, but the increased intensity also places a great deal of stress on the muscle cells more than in lower levels of competition. It is also likely that levels of antioxidants in the diet could enhance the horse's ability to cope with the physical demands of the cross-country jumping phase of a three-day event. The question now becomes how much oxidative stress is too much and how much supplementation is really necessary to combat this stress or if by combating the stress we are disturbing the natural adaptation mechanisms necessary to allow the body to cope with physical and psychological stresses.
In english -- need more anti oxidants in the diet....grass? And can you supplement ENOUGH to meet the need? (I.e., feed enough?)This is nothing new. We have known for a long time that horses can't eat enough to physic themselves during periods of high fitness. The horse does not have nutritional wisdom.
Muscle stress higher at 3 star. Nothing new there. Translation: Fences are bigger and require more strength...
In english, at least from what is posted.
We don't know if we should, or should not, supplement. And if we do, how or what we should.
The rest of it says that *** horses work harder than ** horses, that fit horses do better than less fit horses and that this sort of work is hard work cuz we now have numbers to prove it.
Oh Viney: I had a pony that would eat huckleberries and blackberries...many many a purple mouth in my herd growing up the PacNW with blackberry borders on my parents farm....and had a friend with horses pastured in an old blueberry farm and they ate the blueberries all the time.
Seriously, what's an anti oxident for a horse? Flaxseed? Oils?