Spring and Fall Pastures Can Be Unsafe for At-risk Horses

It is that time of the year again, when grass pastures can be unsafe for at-risk horses!

Grazing management is the key to avoiding problems.

Temperature and sunlight affect the amount of fructans (a type of sugar) stored in fresh grass. In plants, a process known as photosynthesis produces fructan. Photosynthesis occurs only during daylight hours. The sunnier the day, the more fructan is produced in a plant. At night, fructan is available to the plant as an energy source.

Temperature dictates how plants utilize fructan during the nighttime hours. If the temperatures stay warm (40° F or higher), plants use fructan to fuel growth in leaves and stems. Unused fructan is then stored in the lower two inches of the stem just above the soil line. However, if the nighttime temperature drops below 40° F, the plant will not grow and fructan remains in the leaves in high concentrations. For sensitive horses, consuming this grass might lead to colic or laminitis.

Proper grazing management can help avoid a sugar overload. It is best to limit grazing time or stop it completely when daytime temperatures are warm and nights are below 40° F.

To learn more about how sugar and starch affect your horse, enter the word “sugar” in the search box.