Transitioning Horses to Spring Grazing

By Laura Kenny

When winter begins to wind down and spring is right around the corner, many horse owners are excited to turn horses out on pasture. However, there are some potential problems to be aware of and precautions to take when transitioning horses to spring pasture.

Winter Turnout Options

Your spring transition will depend on whether your horse stayed out on pasture all winter or if it was confined to a dry lot or sacrifice lot.

In order to protect pastures and encourage rapid spring establishment, horse owners are encouraged to keep horses off pastures during the winter months. Horses are hard on pastures to begin with, but during the winter, forage plants are dormant and cannot recover from grazing. When soils are wet, horse hooves easily compact soil and damage plant root systems. When horses are kept on pastures all winter, the pastures take longer to recover in the spring.

However, keeping your horse in a stall all winter is not a good solution. Instead, it is recommended to use a sacrifice lot (also called a dry lot) for turnout during the winter months. This is a small area that is not intended to grow forage, but rather to keep horses off pasture when conditions are not ideal for grazing. Horses kept in these areas over winter will need to be gradually transitioned to the new spring grass when winter is over and pastures have recovered in the spring.

On the other hand, some farm owners cannot confine their horses over the winter and instead allow them to remain on pastures throughout the season. These horses will be gradually transitioned to the new grass as it grows in, and will not require horse owners to manage access to the same extent as those whose horses have been confined during the winter.

Why to Transition Gradually to Spring Pastures

Most horse owners are aware that horses should be transitioned slowly to any new feed source. The microbes that inhabit the horse’s digestive tract vary depending on what it is eating. When the diet changes, the microbial population must also change. A sudden feed change does not give the microbial population time to adjust and can cause colic or diarrhea. Therefore, we recommend changing to new feeds slowly over the course of a few weeks. Going from hay to spring pasture is no different.

Early spring pasture grasses also tend to be very high in non-structural carbohydrates (NSC) during spring growth, which can be a problem for certain horses. Non-structural carbohydrates include sugars, fructans, and starch. These carbohydrates are an important energy source for horses, but they can trigger laminitis for some horses with certain health conditions (such as laminitis, insulin dysregulation, Equine Metabolic Syndrome, and Cushing’s/PPID). If you have a horse with these health problems, you should consult with your veterinarian about whether your horse should be allowed to graze or if access to spring pastures should be limited.

Methods for Transitioning to Spring Pastures

If your horses have been confined during the winter, you will need to transition them slowly to spring pastures. It is best to wait until pastures have grown to a minimum of 6 inches before grazing so that the plants have adequate time to recover from winter and grow new leaf tissue.

Once the pastures are ready to graze, begin with short grazing periods for the first few days (15-30 minutes per day). Slowly increase the grazing periods by an additional 15-30 minutes per day until the horse is grazing for 3-4 hours daily. Continue this grazing period for another week or two before changing over to your desired daily turnout time. If possible, time your turnout periods after feeding hay or grain so that the horse is not very hungry when it is offered grass.

Grazing muzzles are another solution to reduce pasture intake if turnout time cannot be transitioned gradually. The muzzle allows the horse to drink water and take small bites of grass, preventing them from consuming large amounts of forage. They can reduce pasture intake by 30-80%, and many factors influence their effectiveness. It can take some trial and error to find a style of grazing muzzle that works for your horse, but luckily there are many on the market. When trying out grazing muzzles, realize that it will take the horse some time to learn how to use it (especially if they have never had one on before). The horse will still need supplemental forage (hay) when it is not turned out.

While spring is the most obvious time to transition your horse to pasture, you may also want to consider these practices any time your horse's turnout management changes. For example, if you bring home a new horse that was on poor pasture but your farm has high-quality pasture, you may want to transition it gradually to the new pasture. If you are rotationally grazing and your horse had to spend time confined to its sacrifice lot due to inadequate forage (in the summer, perhaps), then you may want to transition gradually back to pasture.

What if My Horse was On Pasture All Winter?

Horses that spent the winter out on the pasture rather than confined to a sacrifice lot will be transitioning themselves to the spring grass by grazing it as it begins to grow. At first, very little grass will be available so horses will not be able to eat much of it. As more grass comes in, their digestive tracts will be adjusting to the new feed source. Continue feeding hay into the spring to help with the transition.

While this is less desirable from a plant biology and pasture health perspective, it means most horses will be fine if they are turned out while the pastures are greening up in the spring. An exception would be laminitis-prone horses that have equine metabolic syndrome or insulin dysregulation, as the NSC content of spring grass can become quite high and cause undesirable health issues. It is always best to consult with your veterinarian when making pasture grazing decisions for laminitis-prone horses.

Conclusions

For those who kept their horses off pastures during the winter, it is very tempting to turn horses out on pasture as soon as the grass starts greening up. However, some health issues can arise if the transition to pasture is sudden. Following the methods listed in this article will help to keep your horses and pastures healthy.