Mythbuster Monday: Hay Keeps the Same Nutrition Level from Six Months to Two Years

On Mythbuster Monday, we tackle a variety of equestrian myths to either bust or confirm. Today’s discussion: Does hay have the same nutritional value from six months to two years old?

It’s Mythbuster Monday, where Horse Nation dives into different equestrian myths and provides research-based evidence to either bust or confirm those myths. Today’s topic: Does hay have the same nutritional value from six months to two years old?  How long does it take for the hay to lose its nutritional value? When will the have have no nutritional value? Read further to find out!

Myth: Hay keeps the same nutritional value from six months to two years

Myth or Fact: Fact

Canva/CC

Forage is the foundation of a horse’s diet. On any given day, a horse of average weight should be eating approximately 20 pounds of forage per day. There are different options of hay, including Timothy, Bermudagrass, Oat, Alfalfa, and Clover.

But, how long does hay keep the its nutritional value?

Canva/CC

According to Kentucky Equine Research, hay will lose its vitamin content in the first few months. After that few months, the content stays about the same up to three years if stored in a dry spot with optimal air flow. Vitamin A does not fare well in hay. At 24 hours, the hay has already lost 75% of its Vitamin A content.

Canva/CC

Conway Feed and Supply writes that hay loses approximately five percent of its nutritional value in the first three months. After that, the hay will have a relatively similar nutritional value up until two years old. This article states that the key to keeping the nutrition in the hay is to store it in a dry area. Storing the hay outside where it can be exposed to moisture will decrease the chances it can last two years.

Canva/CC

Clair Thunes, PhD, wrote an article published in The Horse. In the article she writes that protein, mineral, and energy content stays about the same up to two years. However, vitamin A and Vitamin E decrease rapidly in hay. The majority of these vitamins content is lost while cutting. Timothy hay seems to lose the most vitamin content at approximately 60% during the cutting and baling process. Regardless of the early nutrient and content loss. After the first few months, the hay holds its nutritional value for up to three years.

Canva/CC

Kathryn Watts of Rocky Mountain Research and Consulting, Inc., performed a study on three different types of hay: one 100% Italian ryegrass, one approx 75% alfalfa/ 25% brome/orchard grass mix, and one 100% alfalfa. The hay was tested on the day of baling, and at two weeks, two months, six months, nine months, and 13 months. In all three testing samples, between two weeks and two months the hay lost nutritional value, but from two months to 13 months, the nutritional content stayed close to the same.

Canva/CC

The consensus is that hay does hold its nutritional value from six months up to two years. As long as storage is optimal in a dry spot with ventilation, the hay will remain a good source of nutrition for horses. So, Horse Nation, don’t be afraid to feed your horses last year’s cut of hay.


Do you have an equine myth you’d like us to tackle? If so, send it our way! Email your suggestions to [email protected]. Put Mythbuster Monday in your subject line.