Spring Grass: Rich Pickings or Risky Business?

Spring grass is nutritious, we all know that. But just how rich is it?

At peak growth, spring grass can rival a high-calorie conditioning feed in every mouthful. Protein levels are almost double what they are at other times of year, while water content climbs to around 75–85% compared to a more typical 60–70%. That means horses have to eat a much larger volume to meet their dry matter needs. It is a bit of a double-edged sword.

Vitamins and minerals also surge, sometimes reaching up to four times their usual levels. Sounds great on paper, but it is not always that simple. Soil type, fertiliser use, pH, grazing patterns and grass species can all skew the balance, so what looks nutrient-rich may not actually be balanced.

So we have spikes in energy, protein and nutrients. What else? Sugar.

Spring grass is very high in simple sugars like fructose and glucose, as well as fructans. Fructans are a type of complex carbohydrate that horses cannot digest in the small intestine, so they pass through to the hindgut where fermentation takes over.

Ever wondered why behaviour can change so dramatically at this time of year?

When fructans hit the hindgut, fermentation ramps up. This produces gas, and plenty of it, while also altering the pH. That shift can disrupt the microbial balance. Some microbes die off, others take over, and suddenly the whole system is a bit chaotic. Add in the surge of energy intake and you have the classic “joys of spring” behaviour.

Some horses really benefit from this seasonal flush. Youngstock, poor doers and lactating mares often thrive. For others, it is more of a challenge. Good doers, horses prone to laminitis, and those with EMS or Cushing’s can struggle during this period.

The good news is that it does not last forever. As grass matures into summer, it becomes more fibrous and less nutritionally dense.

In the meantime, offering hay, soaked hay or straw can help increase dry matter intake and reduce the urge to gorge on fresh grass. It also supports the hindgut and may help limit excess gas production.

Managing the transition is key. Gradually increasing grazing time over a couple of weeks gives those hard-working gut microbes time to adapt. Get that right, and spring can be a lot more enjoyable for everyone involved.

If you're concerned, confused or struggling with spring grass, get in touch - we're here to help!