Spring Silly Season: Why Horses Get Fresh on Spring Grass

Does your horse suddenly feel sharper, hotter or more reactive in spring? As days lengthen, grass growth surges and horses return to regular work after the winter break, many owners notice behavioural changes. A horse that was quiet and rideable through winter can quickly become fresh, distracted or anxious seemingly overnight, and nutrition is often the hidden cause.

Why Spring Grass Changes Behaviour

Spring pasture is very different from winter forage. After rain and milder temperatures, grass grows rapidly and contains high levels of simple sugars to fuel that growth. Horses grazing lush pasture receive a natural energy boost, essentially a daily sugar hit.

At this time of year, a large proportion of these sugars are present as fructans. These hindgut-fermented carbohydrates can contribute to fizzy, over-reactive behaviour. In some horses and ponies, particularly those prone to weight gain or metabolic sensitivity, high fructan intake may also increase laminitis risk.

However, sugar is only part of the story.

The Potassium Problem

Rapidly growing grass is also naturally high in potassium. While potassium is essential, excessive intake disrupts mineral balance within the digestive system.
Magnesium, calcium and phosphorus share common absorption pathways in the small intestine. When potassium intake rises, magnesium uptake is reduced. This matters because magnesium plays a key role in nerve transmission and muscle relaxation.
Low available magnesium is commonly linked to:

•    nervousness and spookiness
•    muscle tension
•    over-reactivity
•    reduced concentration

So, while your horse may appear overly energetic, the real issue is often reduced ability to regulate nerve impulses.

Why Standard Magnesium May Not Work

Simply feeding traditional magnesium sources such as oxide, sulphate or chloride is not always effective during spring grazing. Because potassium continues competing for absorption, larger quantities may be required, which can upset digestion and unbalance the diet.

A smarter approach is improving how magnesium is absorbed.

When magnesium is bound to an amino acid (chelated), the body recognises it as protein rather than a mineral. This allows absorption via amino acid pathways instead of overloaded mineral transport channels, significantly improving bioavailability.

Magnesium L-Aspartate is a chelated form that maintains efficient uptake even when potassium levels are high, meaning smaller amounts can have a greater calming effect.

Supporting Focus Through the Transition to Grass

Tryptocool is formulated with highly bioavailable Magnesium L-Aspartate alongside additional magnesium sources to optimise absorption and support normal nerve and muscle function during spring grazing. Maintaining magnesium balance helps horses remain relaxed, attentive and rideable as pasture changes.

Vitamin B1 supports healthy nerve function, while Saccharomyces cerevisiae yeast helps stabilise digestion as the hindgut adapts from winter forage to richer grass.

Together these nutrients provide targeted support for seasonal tension, helping transform spring freshness into balanced, trainable energy throughout the grazing season.