Managing Your Spring Pastures

Spring is the time of year when nature wakes up from its slumber and life emerges again. For our pastures, this means fresh green growth begins to sprout from the earth. While pastures are always an excellent source of forage for horses, in the spring, horse owners are advised to exercise caution.

Why Spring Pastures Management Is So Important for Many Horses

As horses transition from their winter diets of hay and/or slow growing pastures, caution must be taken to ensure they can safely transition to a new diet of fresh green grass. Most pastures in North America remain dormant for much of the winter due to cooler temperatures and possible snow coverage. For the warmer climates, such as Florida, pastures may continue to grow, albeit at a slower rate. Yet even here, pastures will become more active and denser with nutrients than that of the winter.

Spring is when warmer temperatures, increases in rainfall, and other factors drive pastures to grow quickly with lush and abundant forage. The issue for many horses is this young, new growth of spring grass and legume plants are high in sugars and starches. This can lead to many issues for:

  • Metabolic challenged horses. For those horses especially sensitive to sugars or starches, spring pasture grazing can be especially troublesome and it is generally not recommended.
  • For any horse not used to grazing on pasture each and every day, a sudden change in the diet with a change in quality of forage (i.e., higher sugars/starches) can be a major contributing factor to colic.
  • Spring pastures are high in sugar and starch and have the potential to overload the hindgut and the beneficial bacteria there.
  • Weight gain in easy keepers. Spring pastures are higher in energy and can lead to substantial weight gain.

To ensure your horse does not suffer digestive upset or other health issues, it is suggested you slowly transition your horse onto spring pastures. For the first few days, you can let your horse graze on the new growth when it reaches 6 inches (15 cm) in height for 15 to 30 minutes. You can increase this grazing time by 30 minutes every few days until you reach 3 or 4 hours. After two weeks of grazing for a few hours each day, you could then assume your horse’s digestive system has safely transitioned and can allow them to graze all day.

Which Forages in Spring Are Appropriate for Horses?

Depending on where you live will determine which cool season plants are appropriate for your pastures. Factors such as climate, rainfall, soil type, plant variety, and even soil nutrients all play key roles in influencing which plants can survive and thrive. Typical cool season grass forages and their characteristics for horses in North America include:

  • Kentucky Bluegrass

    • Optimal growth when temperatures rise above 60°F (15°C).
    • Growth halts when temperatures reach near freezing 32°F (0°C).
    • High nutritional value with range CP 12-17% and DE 0.86 to 1.04 Mcal/lb.
    • Ryegrass

      • Optimal growth when temperatures rise above 68°F (20°C).
      • Growth halts when temperatures drop below 41°F (5°C).
      • Moderate to high nutritional value with range CP 11-17% and DE 0.82 to 1.0 Mcal/lb.
      • Timothy

        • Optimal growth when temperatures rise above 65°F (18°C).
        • Growth halts when temperatures drop below 50°F (10°C).
        • Moderate nutritional value with range CP 11-15% and DE from 0.82 to 1.04 Mcal/lb.

      Typical legume forages in North America and their characteristics for horses include:

      • Alfalfa

        • Optimal growth when temperatures rise above 65°F (18°C).
        • Growth halts when temperatures drop below 40°F (4°C).
        • High nutritional value with range CP 18-22% and DE from 1.0 to 1.2 Mcal/lb.
      • Clover (White)

        • Optimal growth when temperatures rise above 70°F (21°C).
        • Growth halts when temperatures drop below 40°F (4°C).
        • High nutritional value with range CP 15-22% and DE from 1.0 to 1.3 Mcal/lb.

      How Spring Pastures Should Be Managed

      Like your warm season forages, cool season grasses and legumes need proper management to ensure optimal productively. For example, overseeding and fertilizing your pastures is helpful in thickening overall coverage of the plants and helps rehabilitate bare spots. Some general pasture tips to ensure solid growth of your forage plants include:

      • Generally, cool season grasses and legumes should not be seeded in the spring, but rather in the fall. This allows the plants to get established and they will remain dormant over the winter. An exception are areas in the far north with extended cold winters and heavy snowfall. Here, overseeding should take place in the early spring.
      • Likewise, your warm season forages should be seeded later in the spring (mid-May) once the danger of frost has passed.
      • Before fertilizer is applied, it is always recommended to get a soil test (local extension office can help) to determine which nutrients are needed. Usually, spring pastures may only need a light application of nitrogen. A soil sample test will also help determine if additional phosphorus, lime, or other plant nutrients are needed.

      Another major management practice is to always monitor your pastures to maintain optimum productivity. Again, this will depend on what type of plants are in your individual pasture and what region of the world you live in. However, here are some universal tips to help maintain productivity.

      • Only allow horses to graze when the plants reach a minimum height of 6 inches (15 cm)
      • The height of the plants in a horse pasture should generally not exceed 8 to 9 inches. This ensures plants are not too mature and have adequate nutrients.
      • Pastures where plants exceed 9 inches should be mowed down to this height.
      • Plant height across most pastures should not be allowed to be grazed below 3 to 4 inches. This ensures plants can recover and prevents overgrazing.
      • Stocking density is always recommended at minimum 2 acres per mature adult horse.

      Take Home Message

      Proper pasture management in the spring does require some extra labor and monitoring from horse owners. However, with a careful plan, horses do very well on spring pastures. The most important tip is to slowly transition any horse onto a spring pasture. All in all, the nutrients provided from spring pastures are widely beneficial to the horse’s overall health and nutritional status. If you are concerned about your spring pasture management plan, you can always contact us for advice or to answer any of your questions.

      Article By: Chris Mortensen, Ph.D.
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