Re: RC: HELP!!

[CMKSAGEHIL@aol.com]

In a message dated Thu, 26 Oct 2000  1:09:49 PM Eastern Daylight Time, 
DreamWeaver <dreamweaver@gbis.com> writes:

<< At 12:21 PM 10/26/2000 -0400, CMKSAGEHIL@aol.com wrote:
>While Karen is right that ideally, horses should have their selenium levels
>tested, in some areas, there is such a profound deficiency that there is
>virtually no risk of overdose with an injection, given a history of minimal
>or no supplementation.

Heidi:  But won't the selenium supplementation vary greatly depending on 
the horses diet?  Not every horse in the same area is fed hay grown from 
that region.  Or fed the same grain feeds.>>

That is all a part of taking a good history--finding out what a horse is 
eating and where it comes from.  And whether most horses eat local hay or not 
depends on where you are--where we were in Oregon, virtually ALL horses ate 
local hay, because we were in a major hay-producing region, and since our 
deficiency was severe, it was not difficult to understand that all horses 
were fundamentally deficient--the only difference between horses was how big 
the deficiency was.  However, when you live in an area where there is more 
consumption of hay than production (as is the case in much of CA), then you 
are right that the hay can come from virtually anywhere, so you have to know 
the source.  The grain really doesn't make that much difference in most 
endurance horses, as most are on a roughage-based diet--except to the extent 
that one might be feeding a selenium-enhanced feed.  Even there, FDA only 
allows 2 mg per recommended serving, and the daily requirement is 8-10 mg per 
day.

<<I know some horses in No. California who have had really toxic levels and 
serious problems because of too much selenium, and others in the same area 
that are deficient. >>

Northern CA has a special problem because selenium has leached into many of 
the wetlands, and there are actually toxic levels there.  Most of the ag 
lands are fairly deficient, though, but if forages are grown in areas 
bordering wetlands, it becomes another story.

<< Are there other factors that affect selenium levels in 
horses besides what you feed them?>>

I do think some horses inherently utilize selenium better than others.  Also, 
other minerals may tie up the available selenium, making a deficiency even 
more profound, even though the levels are "there" in the feed.

<<Another question:  Do certain types of hays contain more selenium than 
others?  Or is that going to be more related to the field that the hay was 
grown in, rather than type of hay?>>

The slower the hay grows, the better it will incorporate what selenium is 
there.  Therefore mid-summer cuttings will be more deficient than early or 
late cuttings, usually.  But the amount in the soil is the main factor.

Heidi