Perfect Pastures
Dan Moore, DVM
The Natural Horse Vet®

Part Two

Mineral supplements though well intentioned, may give them too much of what they don’t need. Hoof supplements are especially bad for
this – massive amounts often, chosen by man
and based on a RDA (recommended daily
allowance standard) that is 15 years old or
more. Natural minerals and salt like colloidal
minerals and sea salt (often from desert sources
that used to be the ocean millions of years ago)
contain other micronutrients as well, and are
balanced by mother nature not by man. The
confusing issue here is that if you compare
mineral amounts to man-made products,
natural sources often look like they contain
very low levels. But what they do contain is so
much more usable or bio-available that it packs
a much greater, yet balanced, punch! They
literally contain every nutrient and mineral
that was once in the “living oceans”. Often
with man-made our horses over-consume what
they don’t need while trying to get what they
do need. AND what they really need may not
even be in the mix because man is not aware of
it – Natural is better!

Pasture horses must have access to loose salt
and minerals at all times. If they don’t, they can
colic, founder, abort and die almost without
warning. It all comes back to the health of
the horse’s gut. Any sudden change, as we well
know, can be disastrous. Obvious concerns are
getting too much grain or sudden exposure to
lush green grass – but a weather change without
free access to loose salt and minerals can be just
as deadly to a pasture horse. Grass is a living
breathing organism (it just breaths carbon
dioxide rather than oxygen) and its changes
hour to hour – if the grass “thinks” it is going
to die or has less chance of survival it conserves
and prepares – just like we would. Conservation
of water would be a likely action. Grass does
this by actually drawing potassium up from the
ground, and if the soil is heavily fertilized, it can
draw a lot, because a major part of fertilizer is
potassium. Potassium allows the plant to attract
more water. This is good for farmers who sell
hay and crops by the pound but bad for the
actual nutritional value because the grass, crop
or whatever is mostly just water. Devastation
can occur if horses, cattle or other creatures are
exposed to too much potassium at one time. If
you are a cattleman, I am sure you are familiar
with Grass Tetany and Milk Fever, and the
sudden death associated with its occurrence.
These were once thought to be magnesium and
calcium defi ciencies. We now know it is from
high potassium forages and grasses. Similar
situations causing abortions and gut problems
often occur in horses. What happens is that the
potassium spikes during cool, wet conditions
and especially after long droughts followed
by rainfall and rapid growth. Situations like
frost and freezing are especially bad – have
you ever had horse colic after a frost? Probably
so…the reason is a sudden mineral change in
the grass, not just frozen grass! During these
times sodium, calcium and magnesium
decrease, while potassium increases. This spike
in potassium is often deadly. A major problem
like this occurred in 2001 in the Midwest where
reproductive losses occurred in thousands of
horses, cattle, sheep and goats. This was severe
in Kentucky. as well. Often cattle were found
dead just a few hours after frost and freezes.
Mineral blocks just cannot provide the minerals
fast enough for such rapid changes in weather.
Free choice, loose salt and minerals must
be available to pasture horses at all times
if such problems are to be prevented! It is
also important to consider that since sodium
(the Na part of NaCl, or salt) is so similar to potassium, horses often think they have enough sodium (but really have too much potassium) so they stop eating salt. This is especially so in the winter when they need it most. Force-feeding salt is a viable solution particularly in pregnant
mares. This should be in addition to making it readily available free choice. (Always be sure to put any salt product near readily available water). One further point is that fescue alone is usually blamed for abortions in mares when
it is actually the fungus like organisms on the fescue that cause the problems. BUT again it is elevated potassium that generally makes these organisms more deadly! The bottom line here is that less fertilize is better and fescue should be avoided for pregnant mares. It would also seem obvious to me to avoid hay that has been grown on heavily fertilized fi elds – especially for pregnant mares.Now, the big question is how can I make my fields better if I can’t fertilize? The answer is to avoid the typical types of fertilizers – those that are salt based. Salt fertilizers are destroying our environment as well as our soils. Year after year of fertilizer use kills benefi cial earthworms
that oxygenate the soil with their tunnels. Lack of oxygen kills the soil just like it would us. Fortunately, there are “time tested” ways to fertilize that are often even more economical and certainly more benefi cial.