Hay Soaking: All Washed Up or Good Management?

This article is courtesy of Krishona Martinson, PhD, University of Minnesota.

Soaking hay in water is a common strategy used to manage the nutrition of some diseased horses.  Current hay soaking recommendations include soaking hay for 30 minutes in warm or 60 minutes in cold water for removal of carbohydrates (Watts, 2003).  Soaking hay is commonly done to manage horse diagnosed with laminitis, Polysaccaride Storage Myopathy (PSSM), hyperkalemic periodic paralysis (HYPP), and chronic obstructive pulmonary disease (COPD). 

  • Researchers have suggested that diets contain less than 12 and 10% nonstructural carbohydrates (NSC) for horses affected with laminitis (Frank, 2009) and PSSM (Borgia et al., 2009), respectively. 
  • Reynolds et al. (1997) determined that a diet less than 1% K is necessary for horses diagnosed with HYPP.
  • Moore-Colyer (1996) determined that soaking hay for 30 minutes reduced respiratory problems for horses diagnosed with COPD or heaves. 

However, how efficient is hay soaking, and are additional essential nutrients lost during the soaking process?  Researchers at the University of Minnesota set out to determine the impact of water temperature and soaking duration on removal of NSC, crude protein (CP), minerals, and dry matter (DM) from alfalfa and orchardgrass hays. 

Four hay types were soaked, including bud and flowering alfalfa, and vegetative and flowering orchardgrass.  Individual flakes were submerged for 15, 30 and 60 minutes in 25 liters of cold (72°F) and warm (102°F) water, and for 12 hours in cold water.  A control (non-soaked) sample was also evaluated.  Water temperatures were determined by using the cold or warm only faucets, similar to practices implemented by horse owners and managers.  Subsamples of entire flakes were submitted for nutrient analysis at a commercial laboratory.

  • Prior to soaking, both alfalfa hays were below the 10 and 12% NSC threshold for horses diagnosed with PSSM and laminitis, respectively, and would not have required soaking. The orchardgrass hays were above these thresholds, however, after soaking for 15 to 30 minutes were at or below 10 to 12% NSC. 
    • Although soaking hay for longer durations did further reduce NSC content, it is not recommended.  All horses, even diseased ones, require carbohydrates in their diet. 
    • The severely limited NSC content in hay soaked for greater than 1 hour, combined with increased fiber amounts (fiber components are not water soluble, thus they are concentrated in soaked hay), brings into question the palatability and availability of nutrients in hay soaked for longer periods of time.
  • Crude protein leaching was variable in soaked hays, something other researchers have also observed (Moore-Colyer, 1996).  More importantly, previous research looked at the nutrient availability and quality of rained-on hay fed to steers and suggested the nitrogen remaining in rained-on hay is more stable, water-insoluble (Rotz and Muck, 1994), and possibly less digestible by ruminants (Licitra et al, 1996).  Additional research is needed to evaluate this concept when feeding soaked hay to horses.        
  • Calcium (Ca) is not as prone to leaching during soaking compared to other minerals, and appears to be dependent on hay maturity.  As soaking duration increased, leaching of Ca increased in alfalfa bud and vegetative orchardgrass hays (immature hays).  However, soaking had no effect on Ca leaching in the more mature hays. 
    • Conversely, magnesium (Mg) Mg and phosphorus (P) levels were reduced in all hay types as a result of soaking, with longer soaking durations leading to greater reductions.  Because Ca is not as water soluble as P, high Ca:P ratios were observed in hays soaked for  longer durations, specifically after 12 hours. 
    • Ideally, Ca:P ratios should range from 1:1 to 3:1 (up to 6:1) in horse diets (NRC, 2007).  The high Ca:P ratios observed after longer soaking durations were exaggerated in alfalfa hays which had higher Ca:P ratios prior to soaking. 
    • After 12 hours of soaking, a deficiency in P was observed and ranged from a shortage of 1 to 8 grams for a 500 kg horse in light work (NRC, 2007), and Krook and Maylin [32] suggested that osteochondrosis may be associated with excess dietary Ca. 
  • Soaking both alfalfa and orchardgrass hay for 12 hours was necessary to sufficiently reduce K concentration to recommend levels prior to feeding horses diagnosed with HYPP (Reynolds et al, 1997).  Although K levels can be reduced by soaking, neither alfalfa nor orchardgrass hay is an appropriate option for horses diagnosed with HYPP due to the naturally high levels of K. 

Owners should rely on forage analysis as the primary method of determining the appropriate hay for horses, especially when feeding horses diagnosed with laminitis, PSSM, HYPP or COPD.   Hay soaking for short durations (15 to 30 minutes in duration) is an acceptable management method, but should only be used if ideal hay is not available.  Hay should not soak hay for greater than 1 hour.  Soaking hay for long durations resulted in severely reduced NSC content, high Ca:P ratios, shortage of P in the diet and significant losses in DM.

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.

When Should I Feed a Complete Horse Feed?

A complete feed is a fortified grain/forage mix that is formulated with high quality fiber sources to raise the total percent fiber in the feed, so that reduced hay feeding can be done safely. Some fiber sources in complete feeds include alfalfa, beet pulp, and soy hulls. These are all good digestible fiber ingredients for horses.

Here are some of the many reasons why you might decide to feed a complete feed.  

  • You have a horse with poor teeth or no teeth that can no longer chew and swallow hay. This can be a young or old horse.
  • Good quality hay is hard to find, obtain, or pay for. This situation will most likely occur in:
    • Drought situations when plants aren’t growing or they are very mature when they get tall enough to cut. When a plant gets too mature it has high levels of lignin that can’t be digested by the horse leading to digestive upsets or increased risk of colic. Plants also lose nutrient content the more mature they get.
    • Extremely wet conditions because it may be more mature by the time a farmer gets good weather to cut it and flooding can also bring debris onto fields that can be harmful to your horse.
    • Situatinos where hay gets more expensive as fertilizer and fuel costs rise.
  • There is a lot of hay wasted from handling, transporting, ect. More hay is wasted when horses are fed round bales. When hay is expensive and there is a lot of waste, complete feeds may be more cost effective.
  • Hay is hard to handle and round bales/large square bales require a tractor for handling and other equipment such as a flatbed trailer. Equipment requires fuel, tires, maintenance, ect. The cost of handling hay should be brought into consideration when cost is a major factor in feeding.

Long stem forage is an important part of the horses diet and a good source of forage should comprise of at least 50% of the horses daily intake when possible. However, when any of the above conditions exist it may be necessary to feed a complete feed only or reduce the amount of hay being fed. A horse that can no longer chew hay will need to get all of his daily requirements from a complete feed that is easy to eat such as a senior complete feed with softer pellets that can also be fed as a wet mash. If hay shortage, hay cost, or drought is the reason you feed a complete feed you may want to continue feeding some hay in the diet for long stem forage if possible.

It is important to read and follow the feeding recommendations when buying a complete feed, and they should list the recommended feeding amount both with and without hay on the tag. As you decrease the amount of hay, you will need to increase the amount of complete feed. Here are two examples of complete feeds and how much to feed a 1,000 lb maintenance type horse with no hay and with hay/pasture.

  • A senior horse feed – generally a highly digestible and highly palatable product that can be fed as a complete feed, and is designed for older horses. 
    • A 1,000 lb maintenance type horse would receive 12 – 14 lbs of a senior feed, if no additional hay is fed.
    • The same horse, if it was being fed hay, would receive 5 – 7.5 lbs of the senior feed.
  • A traditional complete horse feed – known as “hay replacers” or “hay stretchers” – are a complete feed that combines high quality roughage and grains in a pelleted form. It can be fed as a complete feed or with forage. 
    • If no hay is fed, a maintenance type horse would receive 1.5 lbs per 100 lb body weight. A 1,000 lb horse is recommended to get 1,000/100 = 10 x 1.5 lbs = 15 lbs of a complete feed.
      When feeding along with hay or pasture, a typical recommended amount to feed a maintenance type horse 0.5 lb per 100 lb body weight or 5 lbs.

Whether you chose to feed a complete feed with hay or without, it is important to feed the recommended amount and make adjustments as needed depending on if your horse is an easy or hard keeper. It is also important to provide free choice salt and clean, fresh water at all times. Complete feeds should be split into two or more feedings. Horses should be switched slowly from one feed to another and also when eliminating hay from the diet. When reducing the amount of hay fed, it is recommended to reduce hay over 1-2 weeks.

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!

How to Transition a Horse’s Feed

You may be thinking your horse might be in need of a senior diet, or perhaps there is a new feed available that you believe is even better for your horse.  Maybe you are no longer happy with your current feed.  Or, your dealer no longer carries the product you were using.  Whatever the reason, switching your horse to a new feed is a change that requires care and know-how. 

Changes to feed, pasture or hay in general should be made over a 7 day period, gradually increasing the new and decreasing the old.  For example:

Day 1: 80% of old feed / 20% of new feed

Day 2: 70% of old feed / 30% of new feed

Day 3: 60% of old feed / 40% of new feed

Day 4: 50% of each

Day 5: 40% of old feed / 60% of new feed

Day 6: 30% of old feed / 70% of new feed

Day 7: 20% of old feed / 80% of new feed

Moving from a feed higher in Non-Structural Carbohydrates (NSC) to one that is lower can be done relatively easily by following the instructions above.  If you are moving your horse from a ‘low’ NSC feed to one that is higher in NSC, feed changes should happen over at least the 7 days recommended above, if not longer. 

Research has indicated that horses fed pre and probiotics are better able to handle changes in diet than horses that are not. 

Changes in hay, though generally not given much consideration, can have as much of an impact if not more than changes in feed. If possible, try to follow the same steps as above when transitioning your hay.  Hay that is harvested from the same field, but in different cuttings will likely vary in nutritional content. Hay testing is available from many University Extension offices.  Check with your area extension office for more information.

Vitamin A for horses

Vitamin A is one of the fat-soluble vitamins, meaning it is stored up in the body. It is potentially the most commonly deficient vitamin for horses that do not receive commercial feeds or do not have access to green forage.

Roughages that are green, leafy and not too old will contain carotene, which can be converted to vitamin A by the horse, but roughages that are bleached, or have been weathered and are dark and dusty will not contain sufficient vitamin content to be considered. If good green forage is available, the horse will generally have sufficient Vitamin A to meet its needs. However, if a horse is fed poor quality roughage, supplemental Vitamin A is needed.

Since so many horses are fed hay that is stored for many months, most all commercially prepared grains contain Vitamin A to help combat this deficiency. It is important to remember that horses can develop a toxicity situation with Vitamin A, if high-potency vitamin supplements are fed on top of an already well-fortified grain base.

Total Dietary (ie. Hay + Grain) Requirements for 1100lb horse, According to 2007 NRC Guidelines:

  • 15,000 IU per day for maintenance horses
  • 22,500 IU per day for moderately active horses
  • 30,000 IU per day for pregnant/lactating mares

Times that are especially critical for additional Vitamin A are the last 90 days of pregnancy and during lactation. High performance horses and weanlings also need additional Vitamin A.

The most common signs of Vitamin A deficiency are dry, scurfy skin and hair coat, and runny eyes and night blindness are other symptoms. A few studies have been done that have shown night blindness can actually be induced by depriving the horse of Vitamin A and then fixed by adding sufficient Vitamin A back in to the diet. Hooves may be dry and scaly. There’s also a slower resistance to respiratory infections, stress and diarrhea. Toxicity symptoms can include dry hair, anemia, and increased bone size.

Transition to Spring Pasture

It is no wonder these guys are asking to be let out onto the lush spring grass after such a long and trying winter.  What horse owner could resist those molten brown eyes and soft whisper-nickers, as if saying ‘Let me out, I’ll be good…I promise!’   

We work hard and do our best to provide our horses what they need; pasture seems all too natural to resist. It’s only when you understand the unique nutritional properties of early spring forage, that you can feel better about saying ‘not yet’!

If your horse survived the winter on hay, a hasty  introduction to ‘rich’ spring grass can cause a shock to his digestive system.  If at all possible, keep your horse off grass during the initial growth period by designating a ‘sacrifice’ area or dry lot.  The size of the dry lot will depend on your available land, but generally should be large enough to allow your horse to move about freely and stretch his legs. The sacrifice area serves to protect your emerging pasture as well as allowing you an opportunity to ease your horse’s digestive tract onto new-growth grass. If he is kept in a dry lot during this time, you may consider hand walking, lunging or additional work sessions to keep him from becoming too fresh. 

So what is different about spring grass that we should heed warning? As the strong spring sun warms the earth, the grass in your pasture emerges from its winter dormant state. The first few blades have a critical job of transforming sunlight into food, a process called photosynthesis, that starts the growth of the plant for the rest of the season.  This food is in the form of plant sugar (fructans) and is essential for the plant to grow into a productive pasture contributor for the remainder of the season. 

When overnight temperatures are cool (generally 40 degrees F) the stored energy created during the day is used to grow additional leaves and roots. Extra food not utilized overnight is stored in the plant tissues.  If overnight temperatures drop below 40 degrees F, the plant will not invest in growth and the sugars will remain in the leaves. This is when the new grass is of concern for horses.

Therefore, it stands to reason that when overnight temperatures remain above 40 degrees F, it is the ideal time to start acclimating your horse to the fresh spring grass, because the level of fructans in the grass are likely to be the lowest.

The transition to pasture should be slow and gradual, starting with a period of 15-20 minutes of grazing.  Gradually increase until you have reached your ideal turnout length of time; this may take the better part of a month.  During this time, it is important to monitor the output of your horse; loose, unformed stools indicate digestive upset likely correlated to the increased fructans. For horses with metabolic issues prone to digestive upsets, transitions should made later in the growing cycle onto mature grasses.  In addition to restricting time on pasture, a grazing muzzle can be used to further control intake.

I probably don’t need to tell you that a pasture full of healthy, green growing grass not only looks wonderful, it is  an investment in your horse’s nutrition. Allowing the early grass to grow and flourish, then gradually transitioning to grazing is an investment in your overall nutrition program. Armed with this information, don’t you feel better telling him to wait?

Poisonous to Horses: Plants

As a horse owner, I have come to realize that horses have an uncanny ability to get themselves into trouble.  Whether it be messing with the fence, making play-things of their stall or breaking into the feed room to grab an extra snack, if we don’t want them to get into it, horses seem to find a way to get into it!  If lucky, the vet doesn’t need to be called, but there is usually some upgrading of hardware, the perpetual fixing of the fence or continuously beefing up security around the feed room.  But what about the things that we as humans haven’t built?  What naturally occurring perils of danger will my horse find and get himself in to? 

Pasture grazing is ideal for horses
Cooper as a yearling, grazes in the pasture

As Winter fades and Spring makes a welcome entrance, thoughts turn from feeding hay to blissfully sunny pasture turnout.  Now is a great time to educate yourself about plants that can harm your horse.

March is poison prevention month and as horse owners, knowing what plants are poisonous to your horse can go a long way in preventing trouble.  To help get you started, here is a good resource of information about poisonous plants that grow in the Midwest, from the University of Minnesota Equine Extension Office.

http://www1.extension.umn.edu/agriculture/horse/pasture/poisonous-plants/

If you find plants of poisonous varieties where your horse can access them, please work with your local extension office on methods of controlling exposure.  Also remember to check your garden and landscaping as many plants listed are popular decorations.

It is also important to note that plant variety growth varies by geographic region so be sure to check with your local extension office for information specific to the area in which you live.

So while you may not be able to keep them from breaking the fence, breaking into the feed room (despite the keypad lock on the door) or dismantling the components of their stall, you can be aware of and have a plan to manage the poisonous plants that dare grow near your horse.

Fiber in Horse Feeds

In our previous post, we learned what fiber is and how a horse digests it,and we also learned that a horse consuming 1-1.5% of it’s bodyweight in quality roughage will satisfy its daily fiber requirements.

When it comes to any grain sources that may be added to your horses diet, fiber plays a much smaller role since the amount of fiber that is added by grains is relatively little, but the effect and digestive process is similar. 

When feeding the grain portion of the diet, ensure that your horse is not receiving high quantities of grain meals all at once – typically no more than 5-6 pounds of grain per meal at most. Because grains tend to be higher in starch than roughage, feeding too much at once can overwhelm the small size and quick rate of passage of food through the stomach and small intestine, and allow starches to pass undigested to the hindgut. Digestion of starches in the hindgut releases lactic acids that are toxic to the fiber-digesting microorganisms, which can result in a gas colic episode or laminitis.

Generally speaking, when you look at a the tag from a basic equine ration, the higher the crude fiber level listed, the lower the energy content of the feed.  Of course, there are other factors that must be looked at, such as the fat level, and also possibly the sources of fiber. 

Beet pulp, for example, is often referred to as a “super-fiber” due to the high level of fiber it provides while also providing roughly the same energy level as oats.  While soy hulls and dehydrated alfalfa are common ingredients used to increase fiber levels, a performance horse ration with a higher fiber level may make use of beet pulp to achieve both increased energy and increased fiber levels.

Feeding Fiber to Horses

Do you know the fiber level in your current feeding program?  If you don’t, you are not alone.  Few horse owners can answer that question, and even fewer understand why it might be important or where fiber comes from.  The first and foremost source of fiber in a horses’ diet is their roughage, or hay, source.  Secondary to that is what is present in any supplemental grain sources.

First of all, let’s define what fiber is:

  • Fiber is a measure of the plant cell wall, or the structural portions that give the plant support. 
  • Main components of fiber are the digestible cellulose and hemicellulose, and the indigestible lignin. 
    • As a crop of hay matures, the lignin content increases and the cellulose and hemicellulose decrease.

Here’s what happens as a horse consumes roughage:

  • Some quick digestion occurs in the stomach and small intestine, allowing starches and sugars to get digested as the forages pass through this portion of the digestive system. 
  • The fiber begins to get digested as the feed passes into the hindgut, or the cecum and colon. 
  • Fiber is digested well here is because of the presence of billions of microorganisms (bugs) whose sole function is to digest fiber. 
  • These microorganisms break down fibrous feeds into short chain volatile fatty acids, which are a source of energy for the horse. 

Here is why it becomes important to feed a high-quality, early-growth-stage roughage.  As a plant matures, the lignin portion increases, reducing the energy available from that roughage.  Add that to the other benefits of high-quality roughage for horses, namely the greater availability of other nutrients, and it is easy to see where spending a little more money for better hay is better in the long run for your horse.

So what does it all mean for your horse?  A horse consuming 1-1.5% of it’s body weight per day in quality roughage sources will meet its fiber needs.