What Happens If a Horse Eats Too Much Alfalfa Hay?

white horse on brown grass field

Yes, horses can get hot and agitated from eating too much alfalfa hay. Alfalfa has a higher protein and energy concentration than grass hay, so it should be limited and fed in small amounts.

Protein is required to help muscles, bones, cartilage, skin, hair, and blood develop properly. However, excess protein will cause ammonia to be produced and voided in the urine. Here’s what can happen with too much alfalfa for horses:

Diarrhea

One of the more common reasons for horses eating too much alfalfa is diarrhea. This is because the legume contains complex carbohydrates in the form of cellulose, hemicellulose, and fructan polysaccharides that resist enzymatic digestion in the foregut. This allows hindgut microbes to use them as a safe energy source through fermentation. However, if too many complex carbohydrate sources enter the digestive tract at once, it can form acidic volatile fatty acids (VFA) that produce gases, including hydrogen carbonate, methane, and butane. When VFA reaches the large intestine, it can cause fluid to leak out of the gut, producing loose manure.

This is also why it’s important to make sure that the hay you’re feeding has been thoroughly cleaned and screened. You should also look for hay that hasn’t been in storage for a long time, particularly vitamin E, as the nutrient levels will have decreased.

Another concern with alfalfa is that it can trigger laminitis in susceptible horses because it’s more energy-dense than other types of forage. This can be true, but the cause is more likely multifactorial and involves training, exercise, and an overall diet.

In fact, adding a little alfalfa to a diet that’s normally low in it can be beneficial for some horses with ulcer problems because the legume helps buffer stomach acid. A study done by Texas A&M University compared horses fed Bermuda grass hay with pelleted concentrate and alfalfa hay and found that the horses on the alfalfa had lower ulcer severity scores than the horses on the Bermuda grass hay. If you have a horse that tends to get ulcers, try giving him a small amount of alfalfa a few hours before he is exercised or trailered.

Hotness

Alfalfa has high protein content, which can make a horse hot. The body uses excess protein as energy and breaks it down into simpler amino acids. This process requires a lot of water to work, so when too much protein is consumed, the horse will become hot. In addition, excess protein increases the need to eliminate nitrogen via urine, affecting hydration status and electrolyte balance during and after exercise.

When horses are in rest or light work, they usually can meet their protein and mineral requirements without alfalfa hay. However, the protein content in alfalfa hay can help meet the needs of young growing horses. In these cases, it is important to consider the nutritional requirements of the individual horse to determine if the supplemental protein is necessary.

Some horses, especially those with liver or kidney problems, do not tolerate alfalfa well. In these cases, the high protein content in alfalfa imposes additional metabolic burdens on the animal, increasing the risk of kidney and liver damage. Also, horses that suffer from the genetic muscle disease hyperkalemic periodic paralysis should be fed limited amounts of alfalfa due to its high potassium content.

Overfeeding any type of hay or forage is dangerous to the health of a horse. A horse eating too much of any nutrient-based food can cause colic, a serious illness that causes abdominal pain and may be life-threatening. If you notice your horse has eaten a lot of alfalfa, call your veterinarian immediately.

Skin Allergies

A horse’s skin can be irritated by the high levels of plant matter (cellulose) in alfalfa hay. This can result in a dry, flaky coat. This can also cause itching and hives to occur, both of which can be difficult to treat.

Some horses may also have an allergic reaction to the hay itself. This can be due to an allergy to a specific ingredient or to the dust from the hay itself. If this is the case, the horse should be switched to grass hay, such as Timothy or orchardgrass, as these are typically less dusty.

Another possibility is that the hay itself is contaminated with mould or has been infected by blister beetles (Cymodothea trifolii), which are particularly attracted to alfalfa. If this is the case, it’s important to switch back to grass hay or talk to your hay provider to ensure you buy healthy hay.

Lastly, some horses are simply not well suited to a diet heavy in alfalfa. In these cases, a slow and measured approach is recommended for the introduction of this hay into the horse’s feed.

Generally speaking, feeding a mixture of different hays is ideal for horses as it provides a balanced nutrient profile and helps with digestive health. A mix of hays is often able to provide the same nutrients that a mono-component feed does but at a much lower calorie count. It is also good to start with a clean slate and slowly reintroduce different ingredients, such as micronized linseed, unmolassed sugar beet, and Dengie Pure Grass Pellets, one at a time. This will allow you to see which ingredients don’t trigger unwanted reactions in your horse.

Gastric Issues

Alfalfa is energy-dense and can make horses hyperactive. However, the reality is that these changes in behaviour are multifactorial. Other factors like training, environment, and overall diet play a role. A good feed salesman or equine nutritionist can help create a balanced and optimal ration for each horse.

Another common myth is that alfalfa makes horses hot due to its high protein content. However, this is not an issue if the protein content in the hay is in balance with the rest of the diet and the horse’s specific needs.

If a horse eats a high percentage of alfalfa or consumes more protein than they need, it can lead to gastric upset. The reason is that a horse’s intestinal tract is designed to break down protein, but when the horse is consuming excess protein, it can cause fermentation and putrefaction in the hindgut. This produces too much ammonia, which can be toxic to the liver and kidneys.

Excessive protein consumption also leads to increased urination and sweating, which can impact a horse’s ability to cool down during exercise. This is a greater concern for endurance racehorses, who are expected to sweat extensively during long races.

A good rule of thumb is to always feed hay that has been well-cured and analyzed for the proper nutrient profile. This is especially important when feeding young, growing horses or lactating mares. In addition, a good feed salesman or equine nutritionist can help you tailor the ration to each horse’s specific needs and activity level. This will help keep them healthy and happy and save you money in the long term.

Digestive Issues

Unlike other types of hay, alfalfa has higher protein and caloric content, making it popular for weight gain or high-performance horses that need extra energy. However, it also has a lower level of starch than grass hay. This means that horses eating alfalfa may need to drink more water because it can make the digestive tract work harder.

Another concern is that too much alfalfa can lead to bloat in horses prone to the condition. However, research shows that while a diet rich in legumes can increase the risk of bloating, the problem is more likely to stem from the type of hay or grain being fed than the amount of alfalfa in the diet.

One more thing to keep in mind is that the quality of the hay being used is also important. Heavier bales can indicate that the hay was not properly cured or dried before baling. This can cause problems with mold growth and dust ingestion, which can be a health issue for horses.

If you notice that your horse is coughing a lot after eating alfalfa, it could be because of the dust and mold. If this is the case, the hay should be changed as soon as possible.

Some horse owners worry that alfalfa hay will make their horses “hot.” This is a myth because it isn’t the alfalfa that makes them hot but rather how the horses are being exercised and managed. The truth is that horses can get hyperactive if fed too many calories from any source, including hay, pellets, or grain. The most important thing is to carefully monitor the horse’s behaviour and overall health and address any concerns as they arise.