Events
Groups
Rider Directory
Market
RideCamp
Stuff
Boy, do I love this question. It's not "no alfalfa for performance
horses", it's "no alfalfa EXCLUSIVELY for performance horses". The
primary reason is because it's too high in protein. Even poor grade
alfalfa is usually 15-16%, and good, leafy, rich alfalfa is often way
over 20%. Protein contains large amounts of nitrogen, which in the body
is degraded to ammonia. Ammonia is toxic, so the body tries to get rid
of it, either via sweat, or through the urine. Alot of nitrogen coming
out through the sweat glands is in part what produces that thick,
patchy, lathery sweat which is much less efficient in cooling the horse
than the thin, clear, watery sweat.
Two, to dilute all that ammonia, the horse has to urinate more. In an
endurance situation, he's losing more body fluids than he would be
without the excess ammonia problem, and is more likely to become
dehydrated during an endurance ride. If the horse is kept in a box
stall, as many are, the amount of cleaning and bedding is going to be
increased. Ammonia fumes are going to be greater (in other words, the
stall stinks) which is hardly a good thing for the upper respiratory
tract.
Three, there is some evidence (Glade, Equine Veterinary Journal 15(1)
31-36, 1983) that excess protein slows energy production. In 171
Thoroughbreds running in 563 races, the time required to finish 1673
meters increased by 3 seconds for every 1000 grams of crude protein that
were fed in excess of NRC recommendations. Endurance horses don't tend
to sprint much, but why do anything that might impede energy production?
Four, while alfalfa is excessive in protein, it is deficient in energy
compared to any of the grains. The vast majority of performance horses
are deficient in energy, which is why so many people are always trying
to get more weight onto their horses with corn oil, rice bran,
whatever. This is becoming even more important now that some data is
coming out that horses with a little fat on them do better than
hat-racks do. While excess protein can be utilized for energy
production, it is much more expensive to try to put fat on a horse by
feeding excess protein than is is to provide more energy in the form of
an energy feed.
Five, west coast alfalfa especially is very high in magnesium---the
alfalfa plant seems to have the ability to concentrate magnesium, they
don't know why. Magnesium, ammonium and phosphorus are the three
minerals which primarily make up enteroliths (gut stones). If you're
feeding alot of alfalfa, you're feeding alot of magnesium. AND you're
feeding alot of ammonium from---you guessed it---all that nitrogen in
alfalfa's protein content. Now all you need is a nice load of
phosphorus, from say, rice or wheat bran or lots of grain. Guess what
lots of performance horses are fed? Is it any surprise that enteroliths
are such a problem in causing colic in horses? Here in So Cal, the
majority of horses are fed straight, California-grown alfalfa. And the
incidence of enteroliths is higher here than in anywhere else in the
country. Why would you feed a hay that is supplying two of the three
ingredients needed for enterolith formation when you can get all the
advantages and not nearly as much disadvantage by cutting the alfalfa
ration in half? Doesn't this start to come under the category of "no
brainer"?
Six, alfalfa is very high in calcium. There is some argument that
having a large supply of calcium in the diet gets the calcium-mobilizing
hormones in the body "lazy". Calcium is required for muscular
contraction and a fairly large amount of it is required during an
endurance ride. Assuming the horse isn't munching alfalfa every step of
the way, his body MAY not be able to mobilize sufficient calcium for the
work load and the chances of myopathies such as thumps MAY be increased.
There's also something in the back of my mind about excess calcium
impeding absorption of something else in the gut, but can't remember
what it is right now. Someone else will probably remember.
Seven, there is increasing evidence that some horses just don't tolerate
it well. Horses that are grumpy, grouchy, high, just all-around nasty
customers VERY often settle down when taken off an all-alfalfa diet.
There's also increasing evidence that scratches may be related to high
protein intake levels.
Finally, high protein diets seem to be implicated in increasing the
incidences of osteochondrosis (OCD) in fast-growing foals. But that's
going into nutrition for growing horses, not performance horses, so I'll
leave that one more or less alone.
This is not to say alfalfa is bad. It's a great feed for what it is.
But you shouldn't feed a rich, high protein hay to an equine athlete
any more than you would stuff a 16 oz. top sirloin into a marathon
runner every day. It's just too much of a good thing. There ARE some
instances when I might/would feed straight alfalfa for a specific
circumstance, but a high-performance performance horse isn't one of
them. At Cal Poly, we teach (for all the above reasons) to keep alfalfa
to less than half of the hay ration. At that level, you get all the
advantages and hardly any of the disadvantages.
Hope this helps.
Susan Evans Garlinghouse
Events
Groups
Rider Directory
Market
RideCamp
Stuff