Interpreting an Equine Hay Analysis

Most universities and equine nutritionists encourage horse owners to have their hay tested. However, most horse owners need help interpreting the results of their analysis. Below is a list of some of the primary components commonly analyzed for in hay, and a basic interpretation of each. Keep in mind that additional components can be analyzed for by request (and/or for an additional cost) and that each laboratory will have a unique display of results. Also, remember the analysis you receive is only as good as the sample you submit. For more information on taking a hay sample, click here.

As Sampled vs. Dry Matter Results

When your sample is returned, there will be two main columns of numbers; As Sampled and Dry Matter. As sampled reports nutrients in their natural state, including moisture. Dry matter reports nutrients with the moisture removed. Results reported as dry matter allow for the direct comparison of nutrients across different feeds and often simplifies the ration balancing process; therefore, we recommend owners use the percent dry matter column. In this example, this is the third column of numbers.

Moisture
The optimum moisture for horse hay ranges from 10 to 15%. Hay under 10% may be too dry, leading to brittle hay. Hays over 17% moisture have an increased risk of molding (unless propionic acid is used), and hays over 25% moisture pose the threat of severe heat damage and serve as a potential fire hazard. In the above example, the moisture of this hay is 7.8% (moisture is usually listed above the other components at the top of the report). Please note, this hay was used for a research trial, so was dried prior to analysis.

Equine Digestible Energy (DE)
DE is the measure of the digestible energy in the hay and is used to balance the energy portion of the equine diet. Most hays range from 0.76 to 0.94 Mcal/lb of DE. Different classes of horses require different amounts of DE. For example, a light working horse requires approximately 20 Mcal/day of DE. In the above example, the hay has 0.92 Mcal/lb of DE. If this hay was used to feed a horse in light work, 22 pounds of hay each day would be needed to meet the horse’s energy requirement (20 Mcal/0.92 Mcal per lb/= 22 pounds). Make sure you request an equine DE when having horse hay analyzed as sometimes the default DE calculation is for cattle.

Crude Protein (CP)
Crude protein is a measure of the protein concentration in the hay. Crude protein can range from 8 to 14% in grass hays, 14 to 17% in mixed hays, and 15 to >20% in legume hays. Hay containing approximately 12% CP is thought to meet the amino acid requirements of most adult, idle horses. Other groups of horses (e.g. lactating mares, horses in heavy work, and foals) require greater amounts of CP. If feeding hay with less than 12% CP, supplemental protein sources will likely be required. In the above example, the hay has 15.1% CP.

Acid Detergent Fiber (ADF)
ADF represents cellulose and lignin, the highly indigestible fractions of plant material. The lower the ADF value, the more digestible the nutrients in the hay are. Hays with ADF values of 30 to 35% are readily digested, while those above 45% are appropriate for feeding horses with lower energy needs (e.g. horses at maintenance). In the above example, the hay has 35.9% ADF and nutrients should be readily digested by the horse.

Neutral Detergent Fiber (NDF)
NDF is a measurement of the insoluble fiber and is classified as cell wall or structural carbohydrates. These components provide the plant with structural rigidity. The higher the NDF, the less a horse will consume; it is generally accepted as an indicator of preference. NDF levels between 40 and 50% represent hays that will be highly palatable, while those above 65% will likely not be readily consumed by most horses. However, high NDF hays can be used as “busy hays”. Both ADF and NDF can be used to help determine maturity; the higher the values, the more mature that hay tends to be. In the above example, the hay has 64.8% ADF and will likely be more slowly consumed by horses.

Non Structural Carbohydrates (NSC)
NSC is an analysis of the starches and sugars in the forage. NSC is commonly estimated by adding starch and water-soluble carbohydrates (WSC). Since some horses are very sensitive to dietary starch and sugar (e.g. horses with laminitis and metabolic syndrome), the NSC level can be helpful in selecting hay. Hays containing greater than 12% NSC should not be fed to horses diagnosed with metabolic syndromes, while NSC is rarely a concern for healthy horses. In the above example, there is 5.3% WSC and 0.9% starch for an estimated NSC of 6.2%. This example is teff hay, an annual warm-season grass becoming popular among owners managing laminitic and metabolic horses.

Calcium (Ca) and Phosphorus (P)
Ca and P are two macrominerals required in the diet by all horses in specific amounts. The levels of these minerals can vary among different types of hay. For example, legume hays have high Ca levels relative to P. For the adult, maintenance horse, the Ca:P ratio should be between 3:1 to 1:1. In the above example, the hay has 0.44% Ca and 0.39% P for a Ca:P ratio of 1.13:1. Additional minerals can be tested for if necessary.

Relative Feed Value (RFV)
RFV can be used when selecting hay but is not used in balancing equine rations. Generally speaking, higher RFV reflects higher quality, greater intake, and digestibility. An “average” hay has a RFV of 100 and most agree would be suited for horses in light work. In the above example, the RFV is 87% indicating this hay would be best suited for adult horses at maintenance.

Written by Krishona Martinson, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.

Hoary Alyssum in Hay – Ask the Expert

Hoary Alyssum in HayQuestion: We suspect we have hoary alyssum in our hay. We’ve noticed our horses are stocked-up, but we are not sure if its from hoary alyssum or because all of the snow is limiting their ability to walk around. Can you confirm if this is hoary alyssym in our hay?

Answer: Yes, hoary alyssum is in this hay.

One seed head is circled in red and more can be seen throughout the photo.

Hoary Alyssum can be identified by small, oval seed pods that become translucent as they mature showing the small brown to black colored seeds inside the pods.

We recommend you immediately stop feeding the hoary alyssum-infested hay. Hoary alyssum only affects horses, so the hay can be fed to cattle, sheep and goats.

Horses can react differently to hoary alyssum, but signs of toxicity are usually seen 12 to 24 hours after a horse ingests the plant.

Common signs include swelling and fluid build-up in the lower legs (e.g. “stocking-up”), a fever of 103F or higher, stiff joints, and an unwillingness to move. More severe cases can progress to laminitis.

Mild stocking up is most common; however, more severe signs can occur in horses eating hay with more hoary alyssum or when ingesting the hoary alyssum-infested hay for longer periods of time.

Clinical signs normally go away with supportive treatment 2 to 4 days after removing the infested hay. Horses with laminitis may take more time to recover.

For more information on hoary alyssum toxicity, click here.

Written by Krishona Martinson, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.

Ask the Expert: Large Round-Bales

Question: We are having a hard time finding small-square bales and as a results, are going to start feeding round-bales. How many small square-bales are in a round-bale?

Answer: It depends on the weight of both the large and small-square bales. For example, if the round-bale weighs 1,000 pounds, then 20, 50-pound small-square bales would be equivalent to 1 round-bale. If the large round-bale weighs 1,200 pounds and the small-square bales weigh 40 pounds, then 30 small-square bales would be equivalent to 1 round-bale. It important to know the weight of hay bales both for feeding and economic purposes.
Also keep in mind storage and feeding losses associated with round-bales are usually higher compared to small-square bales. Especially if the round-bales are stored outside and fed without a hay feeder.

This article is reprinted with permission from Krishona Martinson, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.

Tips on Growing and Selling Horse Hay

Five horse hay growers in Minnesota share their tips on growing and selling horse hay, including how they monitor moisture throughout the baling process, how they work around the weather, what types of forages they grow and the investment it takes to grow and harvest hay.

The farmers also share their advice for individuals wanting to grow and/or sell horse hay and their greatest challenges associated with growing and selling horse hay.

This video was shared with permission from Krishona Martinson, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.

Group Feeding Tips for Small Facilities

Feeding TimeWe are a far cry from a fancy operation with four horses on my property to manage.  The horses in our herd live outside in one of two paddocks with fulltime access to a run-in shed which is divided in half.  They get rotational turn out onto the pasture whenever possible.

With the variety of horses we have, our little operation is anything but simple.  And oh how they vary!  One is a 32-year-old hard keeping Arabian mare with a princess complex who has progressively lost dentition efficacy in the last few years.  Next is her 14-year-old gelding son who is an air fern, aka quite possibly the world’s easiest keeper.  Finally the two Warmblood geldings, half-brothers both in light work.  One is a 16 hand, 10-year old fair doer while his brother (12 years) just under 16 hands, tends to be higher strung and a notch or two closer to being a hard keeper than his half-brother.

We feed good quality grass hay in small squares as we don’t have the storage space, equipment or desire to feed rounds. With these parameters, in combination with our variety of personalities, feeding time can be quite….interesting.  Over time, we’ve developed some strategies for making this living arrangement work.  Here’s a few you might consider if you have a similar herd situation:

  • Divide your herd by feeding needs and behaviors
  • Separate the bully of the herd.
  • If possible, put harder keepers with harder keepers, easy keepers with other easy keepers.
  • Keep an eye over time as the herd dynamics shift, the bullies can easily become bullied and go from ideal weight to underweight if you’re not checking regularly.
  • Check body condition score on a regular basis and be prepared to move horses around if dietary needs change.
  • Provide at least as many feeders as there are horses.  More if you can. Divide the ration of hay evenly among them.  This allows those who are bullied by others the chance to get what they need.
  • While on pasture, use a grazing muzzle on the easy keepers so that the harder keepers can have sufficient time with the forage.
  • When it comes to feeding concentrate, use paddock, pasture, round pens, arena etc.  to separate the herd.  This way, those who need a different feed type (example: ration balancer versus a senior feed) can get what they need and have time to eat it.
  • If you don’t have facilities to separate during the time to feed concentrate, consider guarding the slower eater so they can get sufficient time to eat their full ration. This may add time to the chore schedule, but it will help to ensure all horses are meeting their unique nutritional needs.

Keeping multiple horses with a variety of nutritional needs in a smaller space can be a challenge.  But with a little creativity and the right tools, you can be assured everyone gets what they need.  What ideas do you have to manage the variety of horses in your herd?

Estimating Winter Hay Needs

Cooper and Ferris in a snowstorm

Question: We recently purchased a farm and will be housing our two quarter horses over the winter. They are trail horses who are not ridden during the winter. Because I’ve always boarded my horses, I’m not sure how to estimate how much hay I will need for the winter. Can you provide some guidelines?

Response: An adult horse at maintenance will consume between 2 – 2.5% of their bodyweight in feed (hay and grain) each day. For example, a 1,000 pound horse fed a 100% hay diet would consume 25 pounds of hay each day.

  • From October 15 to May 15 (when there is no pasture in MN), the horse would consume about 5,350 pounds of hay or 2.7 tons.
  • This would equal 107 fifty pound small square‐bales or six 900 pound round‐bales during this time.
  • For two horses, this amount would be doubled; 214 small squarebales or 12 round‐bales.
  • It is critical to know the weight of the hay bales; not all bales weigh the same.

If the same horse was receiving 5 pounds of grain each day, their hay needs would be reduced to 20 pounds each day.

  • From October 15 to May 15 the horse would consume about 4,280 pounds of hay or 2.1 tons.
  • This would equal 86 fifty pound small square‐bales or five 900 pound round‐bales during this time.
  • For two horses, this amount would be doubled; 172 small‐square bales or 10 round‐bales.

These estimates assume good quality hay is fed in a feeder to reduced hay waste. When feeding small squares‐bales, hay waste when a feeder was not used (hay fed on the ground) was approximately 13% compared to only 1 to 5% when a feeder was used. When feeding large round‐bales, not using a feeder resulted in 57% hay waste compared
to 5 to 33% hay waste when a feeder was used. Its always best to purchase some extra hay since horses may require additional hay during the cold winter months (depending on their access to shelter).

Author: Krishona Martinson, PhD, Univ. of Minnesota. Reprinted with permission of the author. For other topics from the Univ. of Minnesota Equine Extension, visit their website.

Changing Hay Sources for Horses

As a horse owner, I have moved quite a few horses around and recently moved my gelding to a new boarding facility, so thought this would be a good opportunity to share one aspect of my experience. 

To help maintain as much consistency in his routine as possible, I made sure that I had 2 weeks’ worth of hay to take with me to help keep his diet consistent throughout the move and to allow for a gradual transition to the new hay. 

When I told the barn managers at the new facility that I was bringing a few bales of hay over, they seemed a little surprised at this and told me not to worry about it, because they had really high quality hay.  I asked them if they would recommend a sudden change in a horse’s grain ration, and immediately they said of course not, due to colic risk. I replied, “Then why would you switch their hay cold turkey, when it makes up 60 – 70% of the horses diet?” and watched their expressions as they realized the point I was making.

As a result, along with keeping his grain ration and meal times consistent with the previous routine, a gradual transition from the previous hay to the new hay was done over a 2 week period.  For the first couple of days he received his “old” hay only, and over time we incrementally replaced a small portion of his “old hay” with the “new hay” so that at 2 weeks post-move, he was completely switched over without any problems or decline in performance. 

As horse owners, it is important to keep in mind that ANY sudden changes in diet, including fresh pasture and hay, can disrupt the environment in the gut where communities of microbes reside.  Consequently, this disruption in the microbial population and digestive process can put the horse at risk for GI upsets (e.g. excessive gas production, colic, diarrhea, discomfort, etc.). The energy and nutrient content in hay can vary drastically depending on the plant species, geography, soil conditions, plant maturity at harvest, climate conditions, baling and storage methods, etc.  Even hay that comes out of the same field from consecutive cuttings can have large differences in quality and nutrient content that should be considered. 

It takes approximately 3 weeks for the microbes in a horses gut to adapt to dietary changes, thus making slow, gradual transitions over a 2 – 3 week period important to help prevent GI upset.  When it isn’t possible to make a full two week transition, then allow for as much of a gradual transition as possible even if is only over 2 – 3 days.  Providing dietary pre- and probiotics can also help support gut microbes through dietary changes especially if they are rapid.

Forages for Horses

This blog post is courtesy of Jennifer Earing, PhD, University of Minnesota.

Forage selection should be based on horse needs, as there is no one forage best suited for all classes of horses.  For example, providing a nutrient-dense forage like vegetative alfalfa hay to ‘easy keepers’ can create obesity issues; however, that same hay would be good option for a performance horse with elevated nutrient requirements.  With so many forages available, how does one choose the best option??  Differences in the nutritive quality of forages (hay or pasture) are largely based on two factors: plant maturity and species.

Maturity

Regardless of plant species, stage of maturity significantly affects forage quality. 

  • Young, vegetative forages are very nutrient dense and contain fewer fibrous carbohydrates (hemicellulose, cellulose, and lignin). 
  • As the plant matures (flowers and seed heads are indicators of maturity), the proportion of fiber in the plant increases, to provide structural support as the plant gets larger.  The increased level of lignin associated with maturation interferes with the digestion of cellulose and hemicellulose by hindgut microorganisms, thereby reducing the digestibility of the forage.  
  • More mature forages also have lower energy and protein levels than their immature counterparts. 

Most horses do well on mid-maturity forages; horses with elevated nutrient requirements benefit from receiving young, less mature forages, while more mature forages are be best suited for ‘easy keepers’.

Plant species

Legumes vs. Grasses
Legumes (i.e. alfalfa and clovers) generally produce higher quality forage than grasses.  Often, legumes have higher energy, protein, and mineral (specifically calcium) content when compared to grasses at a similar stage of maturity, and are typically more digestible and more palatable. Legumes are an excellent source of nutrients for horses; however, a horse’s nutrient requirements can easily be exceeded when fed immature legumes.  Consumption of excess nutrients, particularly energy, may result in obesity or other digestive issues.  Legume-grass mixes or mid- to late-maturity legumes (which are less nutrient-dense) often provide adequate nutrients, without exceeding the horse’s requirements.    

Cool Season Grasses vs. Warm Season Grasses

Cool-season grasses (CSG; i.e. timothy, bromegrass, bluegrass, and orchardgrass) typically have a higher nutritive value compared to warm season grasses (WSG; i.e. bahiagrass, bermudagrass and bluestems).  At a similar stage of maturity, CSG have a higher protein content and lower fiber content.  The higher fiber content in WSGs is due to the fact that they mature and become lignified more rapidly than CSGs.  WSGs in late stages of maturity are typically less digestible and may be less palatable than CSGs.  Consequently, if feeding WSGs it may be advantageous to harvest the forage at an earlier stage of maturity, compared to CSGs.

CSGs store the majority of their carbohydrates as fructans, while WSGs and legumes store their carbohydrates as starch.  Rapid consumption of forages containing high levels of fructans, as with other water-soluble carbohydrates, may trigger laminitis in susceptible horses.  Fructan levels are highest in lush spring pastures and often increase during drought conditions.  Carbohydrate content of forage is an important consideration for owners of horses struggling with chronic laminitis issues, equine metabolic syndrome, and PSSM

Differences in average nutritive values of forages commonly fed to horses are shown in Table 1.

Conclusion

The digestive system of the horse has been designed to efficiently utilize forages, and most horses can fulfill their nutrient requirements on these types of diets.  Matching the nutrient levels in the forage to the nutrient requirements of the horse is one of the primary goals in forage selection.  A variety of factors, including plant species and maturity, should be considered when making this decision.

Using Hay Replacers for Horses

Severe drought through parts of TX and OK leaves hayfields and pastures brown and dry, and animal owners searching for replacement options.

When times of severe draught or other weather phenomenon result in poor quality or availability of pastures and hay, horse owners often turn to complete feeds (i.e. feeds that contain a full diet of roughage, protein, vitamins, minerals, and other needed nutrients) or hay stretchers/replacers (designed to replace the fiber component of the hay/pasture that is no longer available).   These products can be extremely useful to horse owners to help them through the tough hay times, but they do come with some usage guidelines to keep horses happy and healthy.

  • Follow the recommended feeding rate.
    • This is of particular concern if the product is being used as the sole diet.  To keep gut health intact, enough fiber must be consumed each day for regular gut function.  And, to keep the horse healthy overall, it is critical to ensure they are receiving all the balanced nutrients that they would normally get through a combination of hay, pasture, and added concentrate feed.
  • Horses tend to crave long stem fiber to chew on, which is missing in the diet made up of complete feed or hay stretchers. 
    • Owners will most likely see unwanted behaviors begin, such as wood chewing, cribbing, or weaving, without some grass or hay to keep their horse’s mouth and mind busy.  While the full daily allotment of hay may not be available or affordable, it is a good idea to offer at least a flake or two each day to help prevent these behaviors (and save your fences).  Hay cubes are an option if pasture or traditional baled hay is unavailable.
  • Ensure proper water and salt consumption.  Proper hydration levels are essential to keeping the gut moving properly.

In the absence of available forage, providing a complete feed concentrate is a better option than feeding a concentrate that is designed to be fed with forage, by itself.  With proper management and attention to detail, both the horse and the owner’s pocketbook can pull through the hay shortage!