Nutrients Provided and How to Buy, Store, and Feed Hay

Good quality hay can provide all of the calorie, protein, calcium, potassium and magnesium requirements (to name a few) for most mature idle horses, as well as those in light to low-moderate work. Certainly, growing horses, lactating mares or high-level performance horses will need additional calories, protein, minerals and vitamins, but a substantial portion of nutrients will still be met by hay.

In addition to providing ample nutrients for all horses, hay provides a horse with fibre, which is important for gastrointestinal health and satisfies their innate “foraging” behaviour.

Despite the nutrients from hay and the physiological importance, most people just buy whatever is available, toss it into a hay loft, and then feed it as a complement to a grain mix. But, in fact, supplemental grain mixes should only be fed when nutrients are lacking in the hay.

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To get the best bang for your hay dollar, you should consider the following advice:

Secure Good Hay

Many hay producers sell their hay through brokers, though you might be lucky enough to find a farmer who will sell to you directly. Either way, you want to make sure you get the most appropriate hay for the best price.

Differences in hay quality depend on the species of plant it comes from, the maturity of the plant when cut, and which cutting of the year the hay is from. A good and experienced eye can help you identify some of these features. If your eye is not experienced enough or your needs are very specific, you are best to have your hay’s nutritional content analyzed. See ‘Get a Hay Analysis’ at right.

Species: Legumes such as alfalfa and clover have higher amounts of calcium and protein (14-20% protein) than grass such as timothy, orchardgrass or fescue (more like 6-11%). Straight legume hay should not be fed to horses unless they are growing, and even then, it should be limited, as it is higher in protein and calcium than most horses actually need (not to mention it is expensive).

Straight grass hay is sufficient for most classes of horses, even though it is lower in protein. This is because mature, non-lactating horses don’t actually need much protein. For example, a 500kg hard working horse such as a show jumper or low level eventing horse, only requires about 862 grams of protein per day, which can easily be met with good quality grass hay (10kg of hay x 9% protein = 900g of protein).

Growth stage: The maturity of the plant when cut influences its nutrient profile greatly, as when a plant grows older and taller, it is more stemmy and has higher amounts of lignin, an indigestible type of fibre, as well as lower protein content. Big seed heads (like > 15cm timothy seed head) mean that the plant is more mature.

Cutting: The cut (first or second cut) can also influence nutritional quality, but to a lesser degree than plant type or maturity. The only way to know for sure is by having a hay analysis done.

Store it Well

Proper storage is vital to ensure you are feeding what you actually bought, particularly if you buy your hay in the fall to last over the winter. Over time, the “dry matter” (non-water portion) of the hay actually breaks down and is lost – up to 10% over an eight-month period. Imagine buying 1,000 bales and losing the equivalent of 100 of them!

Similarly, some nutrients break down over time. Fresh cut, sun-cured hay is a good source of vitamins E and D, as well as beta-carotene, which is used by the horse to make vitamin A. Over time, these vitamins, as well as protein, break down, to the point that hay stored for more than six months will be void of these vitamins, and the protein content will be reduced.

Storing hay indoors is ideal, but it can pose a fire hazard, so I prefer to use a different building separate from the horses. If hay is stored outside, it should be stored up off the ground, on pallets or old tires to protect it from ground moisture, and then should be well-covered by tarps.

Feed it Plentifully

Hay, or other forage such as pasture, should be considered the most important component of a horse’s diet. It should be fed in ample amounts, ideally free-choice. If offering free-choice is not an option, note that a horse should receive about 2% of his body weight in hay per day (eg. 10kg for a 500kg horse) at minimum. A fish or luggage scale with a hay net can be used to weigh flakes easily. Horses that need to lose weight can be fed at about 1.5% of their body weight, or lower as needed, though never below 1%, unless supervised by a veterinarian.

I prefer hay to be fed on the ground, in some kind of tub to decrease wastage, as this is the most natural position for horses to eat and allows them to chew and breathe most efficiently. Slow feeder hay nets or tubs are good for those fed limited amounts of hay to maximize the time it takes them to eat, in order to decrease boredom.

If feeding hay outside, particularly round bales, the hay “hut” type of product that protects the hay from the elements decreases wastage and, ultimately, pays for itself.

Get a Hay Analysis

Even with the best eye to pick out alfalfa leaves or orchardgrass seed heads, you will never know the exact nutrition quality of hay unless you get it analyzed and I wish more hay producers would offer this as part of their marketing.

Getting hay analyzed is simple. You can just use your hands to grab deep within an opened bale to get a sample, or, better yet, use a core sampler, which you can borrow from a feed store or agricultural lab. It is also relatively inexpensive, at under $30 for a basis analysis.

If you do get an analysis, for most growing horses or lactating mares, I would recommend looking for hay with about 14-18% protein. For most athletic horses, I would suggest about 10% protein, and for most idle or light work horses I would recommend in the 8% protein range. Ideally, the fibre fractions should be low as well, with neutral detergent fibre (NDF) lower than 65% and acid detergent fibre (ADF) lower than 45%. In general, the higher these values are, the less energy-dense the hay is. Lower values mean the hay has more calories per unit weight.