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!