RE: [RC] Vitamin E deficiency in horses - Susan E. Garlinghouse, D.V.M.
From: M Paul
latiolais [mailto:hmpl@xxxxxxx] Sent: Saturday, June 17, 2006 4:42
PM To:suendavid@xxxxxxxxxxxxxxxx Cc: Ridecamp (E-mail) Subject: Re: Vitamin E deficiency
in horses
Susan,
>So is vitamin E an
issue for horses in general? The only selenium supplement I have found (and
use) also contains vitamin E. Is there a particular reason for >that?
The
selenium supplements also contain vitamin E because the two work
synergistically. Both are antioxidants, and yes, it’s an issue for endurance
horses because they use up a lot more just during “normal” distance exercise.
It doesn’t imply you’re doing anything wrong, or the horse is being overridden
(although injury will also greatly increase the requirement), just all the
normal wear and tear of trotting down the trail all day increases the body’s
need for substrates that repair tissues working overtime.
The
thing is that even the best quality of any hay contains relatively little
vitamin E, so if your horse’s forage is provided by hay, pellets or cubes, he’s
getting very little vitamin E. The vitamin E content that’s contained in fresh
forage oxidizes pretty quickly after cutting and curing and is pretty much gone
within 4 months or so of harvest. Grain has a little, but not enough. Rice
bran has a lot, and it’s probably a more bioactive form of vitamin E, but there
are other issues with feeding a lot of rice bran that limit its use.
So for
any endurance horse that isn’t getting access to daily fresh green forage, IMO,
they should be getting a daily vitamin E supplement. The natural forms (ie,
green forage, a pound or so of rice bran or the KER supplement) are apparently
more bioactive than the tocopherol forms you can get at Wayy World. For my
money, I don’t lose too much sleep over the exact form if the horse is not
showing any signs of muscle pathology. I give my guys maybe 1000-2000 iu per
day when they’re working, and if I see some nice grass out on the trail, I’ll
stop and let them graze for 10 minutes or so---can’t beat getting those
supplements for free. <g> If I have some muscle injury or tieing up
issues to deal with, then I break out the more expensive supplements.
I tend
to sort of disregard the vitamin E content in the selenium supplements---most
places, those supplements don’t fly off the shelves, and I suspect the majority
of the vitamin E content has long since oxidized. If there’s still some in
there, great, no harm done (the upper daily max dose for horses is roughly
10,000 iu per day). If there’s none in there, as I suspect is the case in many
instances, then I’ll have covered my bases already with other vitamin E sources.
