Ridecamp: Re: [RC] Clicking noise--Maureen's question about magnesium (long)

I forgot to mention something else--potassium levels in forages tend to vary
pretty widely, and are often high enough to throw off the balance between
magnesium and potassium.  In fact, this is a problem we deal with in what we
call transition cows in dairy nutrition--animals that are within 3 weeks of
calving are now frequently given mineral supplements designed to counteract
the effects of high potassium levels in forages, so that they start
mobilizing calcium from their bones in preparation for lactation.
Otherwise, there is such a large demand for calcium at calving that they
pull it from muscle tissue and develop milk fever, which is a temporary
paralysis.

So much for mineral nutrition being simple, huh?

----- Original Message -----
From: "Lisa Redmond" <lredmond23@xxxxxxxxxxx>
To: "ridecamp" <ridecamp@xxxxxxxxxxxxx>
Sent: Thursday, May 16, 2002 10:31 AM
Subject: Re: [RC] Clicking noise--Maureen's question about magnesium (long)


> Maureen--
>
> It sounds like the mare might have felt off-balance while trotting, and
was
> cantering because she felt more stable that way.  One thing I found
> interesting as I was reading through some textbooks to research the
problem
> was that what we typically refer to as grass tetany is a cattle problem.
> Grass grows so rapidly in the spring that it can't take up magnesium very
> efficiently, so cattle that aren't supplemented in the fall and winter
with
> hi-mag mineral don't have adequate stores of magnesium, and we end up with
> animals that can convulse and die.  On the other hand, research with pigs
> has shown the loss of equilibrium and trembling that Rae's mare was
> exhibiting when a magnesium deficiency was induced.  I think this is one
of
> those differences associated with non/ruminant versus ruminant that we
> sometimes see.
>
> Magnesium plays several roles in the body.  It is extremely important in
ATP
> production--the energy currency in the body.  It's also closely associated
> with calcium and phosphorus, and regulates  neuronal irritability. Big
> words, but basically this effects the ability of the muscles to respond to
> nerve impulses.  It is also involved in the maintenance of the central
> nervous system (which might explain the equilibrium angle), heart muscle,
> blood vessels, and bone structure, and calcium regulation.  The tetany is
a
> result of the magnesium deficiency throwing off the ion balance in the
> muscles.  Like calcium, sodium, and potassium, magnesium has a positive
> charge on it, so a deficiency of magnesium would cause a shift in the
> overall electrical charge in muscle cells and affect their ability to
> contract properly.
>
> Marshall Jurgens, the author of one of my favorite feeds texts, defines
> tetany as "a condition where animals have localized, spasmodic muscular
> contractions".  Most of us are familiar with the concept that if we suffer
> from muscle cramps in our legs that potassium helps that problem.
Potassium
> has a single positive charge, and magnesium has a double positive, so a
> deficiency in it can be expected to have an even greater effect on muscle
> spasms.
>
> I mentioned the potassium angle for a reason--I've mentioned before (and
so
> has Susan Garlinghouse) that minerals don't act independently of one
> another.  Excess potassium reduces the body's ability to absorb magnesium,
> which reduces the body's ability to retain potassium, and can lead to a
> potassium deficiency.  This would make the muscle problems more apparent.
I
> know that endurance riders supplement electrolytes frequently, and with
good
> reason.  But if the diet is borderline on magnesium balance, this
potassium
> in the electrolytes might be just high enough to cause a marginal
magnesium
> deficiency.  Rae's horse was fine the next morning, and she did eat
normally
> after this episode, so I suspect that she was able to get enough magnesium
> either from her food or from a mineral supplement to restore the balance
and
> clear up her problem.
>
> There is also a close association between magnesium and calcium and
> phosphorus, and prolonged magnesium deficiencies can result in calcium and
> phosphorus deposits in the aorta among other places (there's that blood
> vessel angle again.)  I don't think this is relevant in this case,
> though--the fact that the mare recovered overnight suggests that any
> deficiency was temporary.
>
> I tend to get carried away sometimes--did this help or confuse you?  =)
>
> Lisa
> ----- Original Message -----
> From: "Ridecamp Guest" <guest@xxxxxxxxxxxxx>
> To: <ridecamp@xxxxxxxxxxxxx>
> Sent: Thursday, May 16, 2002 9:38 AM
> Subject: Re: [RC] Clicking noise
>
>
> > Maureen A. Fager trottin27@xxxxxxxxxxx
> > Lisa said "but the fact that Scarlet's insistence on
> > cantering instead of trotting and her trot feeling "weird", along with
the
> wobbling and trembling sound like a magnesium deficiency--it can cause an
> equilibrium problem sometimes."
> >
> > Lisa, would you be able to elaborate on this, or perhaps can you tell me
> where to find more information on a magnesium deficiency?
> >
> > Thanks in advance,
> > Maureen
> > Reno, NV
> >
> >
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 Ridecamp is a service of Endurance Net, http://www.endurance.net.
 Information, Policy, Disclaimer: http://www.endurance.net/Ridecamp
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