evening feedings of hay in their diet would drink about 4.3 gallons of water
before being exercised the next morning, whereas those who ate hay as well as
grain drank only about 2.9 gallons. As the animals were exercised, it was
discovered that the animals on the hay diet had more water in their gut from
the start and were also able to hold on to the water the ingested since the
fiber inside the digestive system slowed the excretion.
While sweating was similar in both groups, the blood of the hay eating group
showed more fluid than that of the grain eating group. The conclusion drawn
simply pointed to the fact that the animals in the hay group were better
While these findings are logical, there are some detractors to this
study, especially when it comes to performance horses. Rivaling scientists
concede the fact that hay will act like a sponge in the gut and retain liquids,
yet in the case of performance animals this added water into the digestive
tract is not viewed as an advantage, after all, while 30 pounds of hay turn
into 43 pounds of manure, 12 pounds of hay and 12 pounds of oats only turn into
about 25 pounds of manure. They hold that temperature has just as much impact
on the levels of liquid in the bloodís plasma as liquid in the gut.
Additionally, the findings of the hay test are challenged since nobody was able
to measure the amount of water that remained in the fibrous content of the gut
after having been transported to the blood for the duration of the exercise.
Obviously, the high hay diet is not designed for competitive horses that
take part in events during which weight is a concern. On the other hand, during
endurance events, these animals shine.