Your horse eats forage every day, but how closely are you looking at what's going into the feeder? Hay quality varies quite a bit, even between bales from the same supplier. A batch that looks fine from the outside may have problems hiding deeper inside.

Knowing what to check when assessing horse forage quality gives you a better idea of what you're feeding your horse. Some problems are easy to spot once you know where to look, while others require testing. Here's what to examine before deciding whether a batch is suitable.

Color

The color of your hay can tell you a little about how it was dried and stored. Green hay has retained more of its original plant pigments, but that doesn't guarantee better nutrition. Hay that spends longer in the sun may turn yellow while still providing adequate nutrients.

Darker discoloration is more concerning, particularly when you notice brown patches inside a bale. Excess moisture during baling can cause hay to heat up, leaving behind darker areas as it deteriorates. If the discoloration appears throughout the bale, check for other signs of spoilage before feeding it to your horse.

Smell

Good hay has a mild, grassy smell that shouldn't be unpleasant when you open a bale. A sour or musty odor suggests something went wrong during drying or storage.

Excess moisture encourages microbial growth, which changes the smell as the forage begins deteriorating. Unfortunately, contaminated hay doesn't always have visible warning signs.

If a bale smells moldy, don't feed it just because the rest of the batch seems fine. Horses have sensitive respiratory systems, and exposure to mold spores can aggravate breathing problems. Your nose is a useful first check, even though it won't catch every problem.

Moisture content

Hay needs to dry sufficiently before baling because trapped moisture encourages microbial growth. As those organisms multiply, they produce heat inside the bale. Excessive heating damages forage and, in severe cases, creates a fire hazard.

For small square bales, moisture content should generally stay below 18 to 20 percent at baling. Larger bales require lower moisture levels because they retain heat more readily.

You won't always detect excessive moisture by touching the hay. A moisture meter provides a much more accurate reading, particularly when you're evaluating a large delivery.

Leaf retention

Leaves contain a large share of the nutrients found in many forage plants. With alfalfa, for example, leaves contain considerably more protein than the stems. Losing them during harvesting reduces the nutritional value of the finished hay.

When you pull apart a bale, look at how many leaves remain attached to the stems. A large amount of broken leaf material collecting at the bottom suggests losses during handling.

Some breakage is normal, especially with very dry hay. However, a bale consisting mostly of stems may provide fewer nutrients than you'd expect.

Stem thickness

Thick, coarse stems are common in forage harvested later in its growth cycle. As plants mature, they develop more structural fiber and lignin, making the material harder for horses to digest.

Younger forage tends to have thinner stems and is easier to digest. However, stem thickness varies between grass species, so you'll get a more accurate comparison when looking at the same type of forage.

If you're comparing batches of the same hay, differences in stem thickness can tell you something about when each was harvested. Coarser hay isn't necessarily unsuitable for your horse, but it may contain fewer digestible nutrients than hay cut earlier.

Seed head development

Seed head development is another way to assess how mature grass was when harvested. As grasses begin producing seeds, their nutritional composition changes. Protein levels and digestibility decrease as the plants continue maturing.

Hay containing numerous fully developed seed heads was harvested at a later stage of growth. For horses with higher nutritional requirements, the reduced nutrient content may be a concern.

However, mature grass hay isn't necessarily poor quality. Horses with lower energy requirements may benefit from forage that provides fewer calories, particularly if they spend most of their time resting. What counts is whether the hay provides enough nutrition for your horse's individual needs.

Dust levels

Some loose particles are expected when handling dried hay, but a large amount of dust can irritate your horse's respiratory system. Horses with existing breathing problems, such as equine asthma, are even more sensitive to dusty forage.

To check the dust level, gently shake a handful of hay in good lighting. If a thick cloud rises from the material, there's too much dust.

Dust doesn't always come from mold. Dry leaves and stems can break into tiny particles during harvesting or handling. Regardless of the source, excessively dusty hay isn't a good choice for horses with respiratory problems.

Mold growth

Mold thrives when hay contains too much moisture. You may notice fuzzy patches or unusual discoloration inside affected bales, although some contamination isn't visible without testing.

Opening a bale is important because its exterior doesn't always reveal what's happening inside. Moisture sometimes collects in certain sections, allowing mold to develop beneath otherwise normal-looking hay.

Don't assume you can remove a moldy section and feed everything surrounding it. Fungal growth may extend beyond what you can see, and moldy hay poses respiratory and digestive risks. The affected forage should stay out of your horse's diet.

Foreign material

During harvesting, weeds and other unwanted materials can get mixed into hay. Some weeds are toxic to horses, and drying doesn't necessarily remove the harmful compounds. Even a small amount of certain poisonous plants can cause serious health problems.

As you pull apart the hay, look for plants that don't match the surrounding forage. If you find an unfamiliar weed, identify it before deciding whether the hay is safe to feed.

Hay may contain foreign objects picked up during harvesting, too. Pieces of wire or other debris can injure your horse if swallowed. Checking several bales from the same batch gives you a better idea of whether contamination is an isolated problem or something more widespread.

Nutritional content

Appearance alone won't tell you how nutritious your hay is. Two bales that look nearly identical can contain different amounts of protein and energy, which affects how well they meet your horse's dietary needs.

A forage analysis measures these nutrients so you know what your horse is getting from its hay. For example, a horse doing demanding work needs more energy than one that spends most of the day resting. Testing allows you to account for those differences when planning their diet.

Carbohydrate levels are important to examine if your horse has a metabolic condition. Understanding how starch in horse feed affects digestion can help you interpret the results and determine whether your horse needs forage with lower sugar and starch levels.

Keeping your horse's forage in good condition

Once you understand how to assess horse forage quality, examining a new batch becomes a regular part of feeding rather than something you think about only when problems appear. Small changes in appearance or smell sometimes reveal that hay hasn't dried or stored properly.

Still, your eyes and nose can't tell you everything. Nutritional testing provides information that physical inspection can't, particularly when your horse has specific dietary requirements. Combining those results with regular checks gives you a much better understanding of the forage you're feeding and whether it's meeting your horse's needs.