How To Know If Your Hay Is Bad: Essential Horse Hay Guide

Everything You Need to Know About Horse Hay

Horses consume an incredible amount of hay on a daily basis. In fact, most horses require between 12-30 pounds of hay each day depending on their size, metabolism, and other forms of supplemental nutrition. But not all hay is created equal! As a horse lover and equestrian, you must understand how to identify hay that is going bad. Feeding your horse hay that is of poor quality can result in a wide range of health concerns.

So, how do you know if your hay is bad? The best way to know if your hay is going bad is to learn how to identify high-quality horse hay! Signs that your horse hay may be bad include a lack of color or dried-out appearance, a moldy smell, excessive dust, visible mold, or excessive heat towards the center of the hay bale.

Because hay provides your horse with so many essential nutrients, you must provide your horse with the best quality hay available. In times when quality hay is hard to attain, or too expensive for your budget, you may need to supplement their nutrition with other forms of sustenance.

In this post, we will discuss everything you need to know about horse hay including how to identify high-quality hay and tips for storing your hay for the best results. By educating yourself in this important area, you will be able to ensure your horses’ health and happiness well into the future.

Why Do You Feed Horses Hay?

Hay is an essential part of any horses’ diet. In the wild, horses graze primarily on grass. However, high-quality grass is not often available in this quantity in a farm or stable environment. Hay allows equestrians to keep their horses happy and healthy, regardless of the environment or climate conditions. Hay provides your horse with the nutrients and metabolic fuel it needs to remain in optimal health. 

Horse Hay vs. Straw

Hay or straw – is there really a difference? While these terms are often used interchangeably, there is a difference! Hay is essentially a mix of dried grasses and plants that are grown to be harvested specifically for animals. Straw, on the other hand, is simply a byproduct of grain crops such as wheat. Because of this, straw is not nearly as high in nutritional value as hay.

Identifying High-Quality Horse Hay

As we mentioned previously, the best way to learn the signs of hay that is going bad is to educate yourself on identifying high-quality horse hay. This skill is of utmost importance, especially if you are the individual responsible for purchasing hay for your horse. 

Over time, identifying high-quality horse hay will become second-nature to most equestrians. However, here are a few tips you can follow as you take a closer look at the quality of horse hay.

Slightly Green in Color

As with any other type of food for both humans and horses, the fresher the better! One of the best ways to gauge the freshness of a bale of hay is to look at its color. High-quality horse hay should be slightly green in color. Additionally, the color should be relatively consistent throughout the bale, including the areas that may have been exposed to the sun. 

Sweet in Smell

There are not many smells quite as satisfying as high-quality horse hay. Good quality hay should be somewhat sweet in smell. If you have spent any amount of time around horses, this smell is likely one to which you are well-acquainted. 

Consistent Temperature Throughout Hay Bale

High-quality horse hay that has been baled and stored properly should be relatively consistent in temperature throughout the bale. Unfortunately, if the hay was too wet when it was baled, the center of the bale can become moldy, generating heat in the process. Of course, depending on the weather and climate, you may notice some slight variances in temperature throughout the bale. However, this should be a warning sign to further investigate the issue.

Soft & Pliable to the Touch

Hay that is high in quality will have fine stems that are small in diameter. This signals that the plant was less mature when it was harvested, keeping many of the nutrients that are so important to your horses’ health. Because of this, high-quality horse hay should be soft and pliable to the touch. When you squeeze a handful of hay in your hand, it should not feel as if you are squeezing a handful of sticks. Rather, it should more closely resemble grass or a fresh plant.

Being able to provide your horse with quality food is just one aspect of horse care. I have an entire article dedicated to sharing tips and tricks about caring for your horse. Read my article, How to Care For a Horse: Ultimate Guide For Beginners, to learn more.

Signs Your Hay is Going Bad

So, we now know how to identify high-quality horse hay. But even the best quality horse hay can go bad if it is stored in improper conditions. It is always best practice to carefully inspect horse hay before you make the purchase, especially if you are accepting a large delivery for your boarding barn or stable. Purchasing poor quality hay can not only cause financial loss but can also result in health concerns for your horses.

Here are a few of the most obvious signs that your hay is going bad: 

Lack of Color

High-quality horse hay that is dense in nutrients should be slightly green in color. Hay that is going bad may be more similar in color to straw, with areas that are bleached or lack color. As you look through the hay bale, be on the lookout for areas that are inconsistent in color. Hay that has been exposed to too much sun will quickly become dry and bleached, stripped of many of its essential nutrients.

Smells Like Mold or Mildew

Unlike the sweet smell of fresh, high-quality hay, hay that is going bad may smell like mold or mildew. Even if there is no visible mold, steer clear of any hay that hints of mold! Additionally, if the hay lacks smell or smells stale, it is likely not as fresh as you may have been told. 

Seems Excessively Dusty

High-quality horse hay that is full of nutrients should not have excessive amounts of dust. In fact, horse hay should not be dusty at all! As you are inspecting the hay, shift through a bale to see if there is any dust that is released in the process. While some fallout is to be expected, exceptionally dusty hay can cause harm to the respiratory system of your horse.

Visible Mold

Even the smallest sign of mold should be a sign to steer clear! Before you purchase or accept a delivery of horse hay, be sure to cut open a bale to inspect the flakes of hay towards the center. High-quality hay should be relatively consistent in color. Moldy hay, on the other hand, may have darker areas that are black or grey in color. 

Moldy hay is a sure sign that the hay was too wet when it was baled. Not only does this damage the quality of the hay and impede the nutritional value, but it may cause serious digestive issues for your horse such as colic.

Excessive Heat in Center of Hay Bale

Another problem that can be a result of hay that was too wet when it was baled is a bale that is excessively hot in the center. This is another reason to cut open a bale of hay before you purchase or accept the delivery.

When mold begins to grow in the center of a hay bale, heat can be generated in the process. In extreme cases, the hay can get so hot that it may even catch fire! Obviously, you should do everything in your power to mitigate this risk. 

Tips for Storing Horse Hay

It is no secret that high-quality horse hay is not cheap! However, it is one of the best ways to invest in your horse’s health and happiness. Because high-quality hay requires an investment, you must take steps to optimize storage.  

Always Check the Quality of Hay Upon Arrival

As we have mentioned previously, one of the most important things you can do is to inspect the quality of your horse hay upon arrival at your farm. Oftentimes, horse owners purchase large quantities of hay in order to receive a discount. Take your time to inspect several bales, looking for the signs we mentioned above. The hay you purchase should be at peak quality when you accept the delivery.

Invest in Hay Analysis to Verify Quality of the Hay

If you are caring for several horses, or you board horses as a business venture, you must invest in nutrient-dense hay. When you are working with a new supplier, it may be wise to invest in a hay analysis. This test, done in a laboratory, will give you further insight into the true quality of the horse hay. 

Store Hay in Cool, Dry Space When Possible

When hay is exposed to heat, sun, or moisture, it will go bad more quickly. It is important to carefully consider the location in which you store your hay to maintain its condition for as long as possible. The best place to store your hay is in a cool, dry space where it is not exposed to any natural elements.

Stack Hay Bales on Pallets or a Layer of Old Hay

In addition to storing hay in a cool, dry location, it is best to keep your fresh hay off the ground. When hay comes in contact with concrete flooring often found in barns, it will be exposed to unnecessary moisture. This can cause horse owners to lose at least the bottom half of their hay stores. 

Instead of storing your hay directly on the barn floor, stack your hay bales on pallets or a thick layer of old hay or straw. This will also act as an added layer of protection, deterring pests and rodents. 

How Long Can You Store Hay?

Oftentimes, horse owners will purchase hay in large quantities as this is often offered at a discount. Hay can be stored indefinitely as long as it is kept in proper conditions. However, in areas where moisture is present (most of the country), hay is best if used within three years.

Because hay requires a considerable amount of storage space, it is often impractical to purchase excessive quantities. Additionally, hay begins to lose nutritional value with each passing year, another reason to restrict your stores to what you will use within the foreseeable future.

Nutrients in Horse Hay

High-quality horse hay consists of a number of plants and grasses. Because of this, it is high in nutritional value! Horse hay contains vitamins, fatty acids, carbohydrates, protein, and minerals. Some of the key vitamins that your horse receives from hay include Vitamin A, Vitamin D, Vitamin E, and Vitamin K. In addition to the nutrients that your horse receives from hay, you may need to add supplemental vitamins to their daily diet.

Risks of Feeding Your Horse Hay That Has Gone Bad

You may be tempted to purchase poor-quality horse hay to save a few dollars. This, however, is not just a bad practice but can also be harmful to the health of your horses! 

Respiratory Issues

Similarly to humans, hay that is moldy or contains excessive amounts of dust can cause respiratory issues for your horse. While this may not seem like a big issue, it can lead to discomfort and illness that can impact your horse’s overall health and wellbeing. 


Bad hay, especially hay that is moldy, can also have a negative impact on your horse’s digestive tract. Bad hay has been known to cause colic in horses, an incredibly uncomfortable condition. Colic, when left untreated, can lead to serious health issues or even death. 

Lack of Nutrients

Finally, as a horse owner, it is your responsibility to ensure that your horse has the nutrients they need to survive. When you feed your horse hay that has gone bad, it is essentially empty calories. They are not receiving the nutrients they both crave and deserve. By taking the time to educate yourself on the importance of high-quality horse hay, you can provide your horse with happiness and health well into the future.

Want to learn more about what horses can eat? Check out my article The Ultimate Guide to What Horses Can (And Can’t) Eat.

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Carmella Abel, Pro Horse Trainer

Hi! I’m Carmella

My husband and I started Equine Helper to share what we’ve learned about owning and caring for horses. I’ve spent my whole life around horses, and I currently own a POA named Tucker. You can learn more here.

Thank you for reading, and happy trails!

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