Willow Oak Ranch

Nutrition

Based on the nutrition guidelines set by Dr. Robert E. Bray (PhD in Animal Nutrition, current UC professor of Equine Nutrition), we at Willow Oak believe in the following:

• A horse’s diet needs to be measured in terms of weight, not volume
• Most adult horses need to be fed a minimum of 1.5% of their body weight (BW) in the form of forage
• At least 50% of this forage should be in the form of long-stemmed hay while processed feeds, such as cubes and pellets, should not consist of more that 50% of your horses diet
• Alfalfa should never be more that 50% of your horse’s diet
• 1.9g of crude fiber per pound of body weight is necessary to maintain gut integrity
• The maximum amount of balanced concentrate fed per day is 1.25% BW with no more that 5lbs fed per meal
• Dietary adjustments should be made in increments of ½ lb per day for hay and ¼ lb per day for concentrates
• Horses should never be fed directly off the ground
• Water should be provided free-choice without use of automatic waterers so that water intake can be observed and that a lack of drinking will not go unnoticed

Why alfalfa should never consist of more than 50% of your horse’s diet…

Here on the west coast, Alfalfa hay is a pretty popular feedstuff for horses. While a good source of protein, it is unsuitable and even dangerous to feed your horse a diet that consists only of Alfalfa hay. Here are some basic requirements for an 1100lb maintenance horse and how Alfalfa compares to those requirements:

So what? What do these numbers mean to the average horse owner? Lots of horses are on an all alfalfa diet and seem to be okay, so why the big deal? Well, let’s break it down biologically. A diet so extreme in either exceeding or falling short of the horse’s requirements has the following ramifications:

• Most importantly is the lack of fiber. Fiber in the horse’s diet sustains gut integrity. Fiber absorbs water in the horse’s GI tract and causes the gut to contract vigorously. When a horse’s diet has insufficient fiber, these gut contractions happen less frequently and colic is more likely to occur. Impactions form as the gut becomes poor at moving food through it’s system. A diet with the recommended amount of fiber not only assures proper gut motility, but will also help keep impaction, obstruction, and sand colic at bay as the horse is able to move these items out of his system.
• Another serious consequence of this all-alfalfa diet is the calcium to phosphorus ratio. The excessive calcium of the diet acts as a buffer and therefore raises pH of the hindgut. Why should you care? A higher pH in the hindgut has been associated with intestinal stones (enteroliths) forming in the hindgut. These intestinal stones are a major cause of colic and can only be removed surgically. Other factors that contribute to the formation of intestinal stones are
• High intake of magnesium
• High intake of nitrogen
• Amazingly enough, alfalfa hay provides an excess of both magnesium and nitrogen (this nitrogen is coming from all the protein in that alfalfa hay!) Therefore, alfalfa has been implicated in the formation of intestinal stones and is the reason why no one outside of California deals with enteroliths: alfalfa is not as common in other parts of the country, is not fed as much to horses, and therefore there is almost no enterolith formation outside of California.
• A possible benefit to alfalfa hay seems to be all the protein it provides. But, again when we break things down biologically, this is not such a good thing after all. Protein is simply a chain of amino acids linked together by a peptide bond. Of all the amino acids required by mammals, lysine is the most important. While alfalfa hay provides a lot of protein, it does not provide any lysine whatsoever. Lysine is a critical limiting amino acid, meaning that it’s deficiency causes the body to use less of the other amino acids. And since there is no storage of amino acids in the body, these other amino acids leave the body via the urine. Also, the horse’s diet is not normally deficient in protein. The horse is a hindgut fermenter, meaning that the hindgut contains trillions of microbes that break down the fiber and a by-product of microbial digestion is protein. This microbial protein source meets the requirements of the horse, which is why a horse on an all grass hay diet will still have enough protein to meet his energy demands.
• Excessive nutrients in an all alfalfa diet can cause a metabolic imbalance which can lead to laminitis. Lamina attaching the coffin bone to the hoof wall can become necrotic as the result of a metabolic insult and this leads to rotation of PIII (coffin bone

Simply put, we in California are lucky to have such ample access to a rich forage such as Alfalfa hay. However, as most things in life are, too much of a good thing can be hazardous. While the maximum amount of alfalfa hay in a horse’s diet should not exceed 50%, the ideal proportion of alfalfa hay as part of your horse’s diet is around 30%.