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A Safer Always Have Hay Source – Mature Grass Hay

The #1 concern and source of stress for customers I have had the pleasure of speaking with is they worry about their horse “standing around with nothing to eat” or their horses are eating dirt, manure or shavings. This article focuses on the plight to choose the safest, always have hay source to slow feed if you can't test your hay. If you do test, the palatability factors described can still be used to your advantage!


Meals vs Free Choice/Always Have Forage

Meals are most often fed due to convenience or concerns about a horse's weight - and rightfully so. Obesity promotes inflammation and a host of other health challenges. However, meals restrict access to forage, which presents its own adverse effects - both mentally and physically.

Chew time is critical mentally and physically for grazing herbivores. Horses, donkeys, mules and their miniature counterparts produce gastric acid 24/7 in preparation for constant food uptake. Why? Physically and mentally they are designed to have access to forage 24/7. Chewing activates saliva production (an alkaline substance), which buffers the gastric acid. In addition, the digestive tract depends on a steady flow of fiber to maintain a healthy microbial population and promote gut motility. It's a perfect balance if we follow nature's design.

Slow feeding allows us to both slow consumption – and ensure an always have hay source to extend chew time.

4 Reasons Mature Grass Hay is a Safer Option

The most mature grass hay (head without seed) or grass hay straw (mature grass hay with the seed head harvested) is your best bet as an always have hay source for four reasons:
  1. It is the least palatable due to higher neutral detergent fiber (NDF) values, therefore naturally slowing the rate of consumption.
  2. Has the lowest propensity for storing sugar and starch (2nd to environmental conditions).
  3. You can visually identify the maturity of a cutting.
  4. The increased fiber requires longer chew time, naturally slowing the rate of consumption.
mature orchard grass hay straw

Did You Know?

Grass hay straw is a crop cut after seed heads have been harvested. Grass hay farmers routinely harvest seed heads for future plantings and subsequently cut the remainder of the crop selling it as grass hay. It's rarely labeled straw.

NDF% and the Palatability Factor

NDF is a measure (percentage) of insoluble (indigestible) fiber. Insoluble fiber isn't broken down by digestion or absorbed into the bloodstream. It simply adds volume/bulk. In theory, the higher the NDF, the more mature the cutting and the less palatable the hay will be. Mature hay has a much higher stem-to-leaf ratio. NDF percentages ranging from 40 to 55 are considered optimum for palatability and digestible energy. My tested hays have averaged 64% NDF over the last 12 years.

Tip: You can use higher NDF hays to your advantage if you want to add bulk and chew time to your horse’s diet! Just be sure to offer the additional fiber in an appropriate slow feeder to slow consumption, along with available water, salt and a healthy dental profile for optimum mastication.
Learn more about the palatability factor: Can Horses Eat More Hay Without Weight Gain? The Surprising Factors

What About NSC?

Non-Structural Carbohydrates (NSC) refer to the sugars and starch levels in your hay. The main contributing factors to NSC levels are:
  1. Environmental conditions
  2. Maturity
Low NSC (10% or below) straight grass hay is recommended for miniature horses, donkeys or individuals that are overweight, insulin resistant or have Cushings disease. Testing is the only way to accurately determine NSC levels in forage. Fortunately, maturity can be seen with the naked eye.

Testing Hay – What You'll Learn

Testing your hay enables you to:
  • Accurately determine the percentage of NSC present in your hay. Note: It’s impossible to visually identify accurate levels of NSCs, regardless of the cutting or type of hay. Learn how to test your hay, where to send the sample and how to calculate NSCs using the results.
  • Identify the amounts of protein, major and macro mineral content, nitrate levels, ADF%, NDF% and more. This information allows you to accurately balance the diet with proper levels and ratios of nutrients that are missing in the hay. Dr. Eleanor M. Kellon, VMD offers comprehensive courses online to learn how to formulate a custom vitamin mineral mix to balance your horse’s diet according to your hay test results. 

When You Cannot Test – Focus on Maturity

If you don't have the ability to store enough hay to make testing it worthwhile - or you board your horse -  you have a few options.

Although feeding untested hay is always a risk, the safest option is to offer slow fed* higher NDF (mature) hay with empty seed heads or grass hay straw (mature grass hay with the seed heads harvested) in addition to a limited amount of lower NDF (immature) hay. Your horse will eat the more palatable, lower NDF hay first and have his slow-fed higher NDF available to nibble on the rest of the time. The free choice forage benefits can prevent an array of adverse mental and physical conditions such as colic, ulcers, and stereotypies to name a few.

Note: The NDF value (percentage) increases with maturity. A simple comparison could be; 20 lbs. of a lower NDF (immature) hay may equate - in digestible energy, protein, nutrients, sugar/starch content and calories - to 30 lbs. of higher NDF (mature) hay. You are feeding more to extend chew time with the goal of achieving slow fed free choice forage. 

If you board your horse, it may be worthwhile to buy your own supplemental slow fed,* always have hay source (higher NDF/mature) and have them feed limited amounts of the hay included in your monthly fee.
*  We define slow fed as the smallest mesh size the individual can extract hay from without frustration. See Choosing A Mesh Size for more tips.

Cutting Verses Maturity

Cutting and maturity are not synonymous. Grass hay crops are cut and baled numerous times throughout a season. Whether it’s first, second or third cutting does not depict the maturity of the plant when it is cut.

How to Identify Maturity

You can easily identify the maturity of a cutting by opening a bale of hay or pulling multiple bunches from the sides.
  • Immature grass hay cuttings will be shorter and softer with no seed heads and a high leaf to stem ratio. The length is typically 3” – 5”.
  • The more mature cuttings will be longer and more course, with a higher stem to leaf ratio, empty seed heads or void of seed heads (straw). The length is typically 9” – 16”.
All stages provide nutrients. Mature hay is never void of nutrition.
High Quality Immature Orchard Grass Hay.
High Quality Immature Orchard Grass Hay
High Quality Mature Bermuda Grass Hay
High Quality Mature Orchard Grass Hay
Tip: Keep in mind that hay is grass with the water reduced. Each mouthful is a more concentrated source of calories. Hay contains seven to eight times more calories than live grass per pound. Grass is 70 to 80% water as opposed to sun cured hay at 5 to 10%.

Quality Verses Maturity

For some, the definition of quality can be debatable. If your goal is to:
  • Offer more palatable hay and feed the least amount of forage to meet the daily caloric requirements in order to maintain body condition and energy requirements - then more immature cuttings (low NDF) would be considered higher quality hay.
  • Provide more volume and chew time - then a good quality mature forage (high NDF) is key.

Quality forage, for all intents and purposes, is free of adverse odor, dirt, mold, weeds, trash or other foreign materials with acceptable color.

Using the Palatability Factor to Naturally Slow Consumption

  • Less palatable hay should naturally reduce the rate of consumption. When combined with a slow feeder, which prevents them from picking through it, you’ve got a win/win situation!
  • Cool season grasses - such as orchard grass, timothy and rye (having the highest propensity of all grass hays to be high in NSC’s) - tend to be more palatable than warm season grasses (such as bermuda, teff and tifton hays).
  • Feeding a combination of warm and cool season grasses can be beneficial by providing a more diverse amino acid profile.
  • ​My preference is a slow fed mature warm season grass hay as an always have hay source and a slow fed cool season grass hay in limited amounts. Both my orchard grass and bermuda hays are tested with confirmed NSC levels well below 10% and averaged 64% NDF. My horses have consistently preferred orchard grass over bermuda despite the maturity of the cutting.
  • If you feed more than one type of hay, feed them separately. Blending less palatable hay with more palatable hay will defeat the natural influence of the palatability factor.
  • Learn how to introduce new forages gradually, step by step.

Additional Tips

Implement Slow Feeders

Using slow feeders or bale nets promotes increased chew time and further reduction of particle size. Chewing activates saliva production providing moisture (higher saliva to forage ratio) and aids in digestion. The faster they eat, the quicker the stomach empties. Once the stomach becomes two-thirds full, it begins to empty regardless of how well the particles are prepared to advance to the small intestine. Gastric acid aids in the breakdown of feed particles combined with the enzyme pepsin initiating protein digestion in the stomach. This better prepares fiber content for optimal digestion as it travels through the remainder of the digestive tract.

Perform Routine Dental Exams to Avoid Colic

Include exams for all ages to check for retained caps, lost and/or broken teeth, abnormal or uneven bite planes, infected teeth and/or gums, periodontal disease and hooks - which are sharp protrusions of teeth that can penetrate the opposing gum.

High NDF forage requires optimum mastication (grinding), which depends upon unobstructed motion of the jaw. Any condition causing pain can discourage the required chew time necessary for proper digestion - and may induce colic and/or choke.

Feed From Ground Level

​A natural grazing position allows the mandible (jaw bone) to come down and forward in the atlantoaxial and temporomandibular joints. This enables the mandible to move freely up and down, side to side, forward and back without any restriction. This free movement facilitates natural wear of teeth along with optimum mastication and reduction of particle size.

Supplement for Balance

Unlike their domestic counterparts, horses in the wild have a wide variety of forages to choose from. They self balance naturally. Every hay-only diet requires supplementation. No hay is ever balanced to itself (optimum ratios), nor will it contain the National Research Council (NRC) minimum requirements of all vitamins and minerals. If you don’t test and balance your hay, feed at least the minimum requirements of salt, a healthy source of omegas and a comprehensive concentrated vitamin mineral supplement to promote optimum immune, hormone, neurological and thyroid function. 

Concluding Thoughts

  • While it is common knowledge that free-choice forage is optimum for all grazing herbivores mentally and physically - finding solutions within domestic environments can be challenging.
  • Consult your veterinarian prior to making dietary changes. 
  • ​Research is lacking to accurately determine the bio availability of nutrients comparing low NDF hay to high NDF hay in horses.
  • Always introduce any new feedstuff gradually.
  • Offering a natural lifestyle, routine exercise and an appropriate diet promotes a happier, healthier herd and can relieve your stress levels as well!

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Monique Warren, Hay Pillow Founder with the Hay Pillow Slow Feeder product line - standard ground hay pillow, mini hay pillow, hanging hay pillow & horse trailer manger hay pillow

About the Author

Monique Warren invented the Hay Pillow® slow feeder and is the owner of Hay Pillow Inc. ​Warren has been an equine guardian for over forty years and slow-feed advocate for over 10 years. She contributes equine nutrition, digestive and hoof health articles to publications such as Equine Wellness, The Journal, The Naturally Healthy Horse, Natural Horse Magazine, Nicker News, The Horse's Hoof and Miniature Horse World Magazine. Equine nutrition and horses feet are her passions. She resides in Southern California.

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