Updated: Apr 6
It’s that time of year again – SPRING GRASS!
Spring pasture grasses are capable of accumulating high amounts of 'Nonstructural Carbohydrates (NSCs)', which are implicated in equine nutritional diseases associated with rapid fermentation, and chronic metabolic disorders. The types of NSC's found in grasses fall primarily into three categories: sugars (glucose, fructose, sucrose), starches, and fructans.
I often get asked about Spring grass, pasture management, and how to best to manage your horse's routine, so here are a few facts and some recommendations:-
New Spring grass, in particular, is typically high in ‘fructans’. Fructans are the primary storage carbohydrate in cool-season grasses predominantly found in UK pastures, (namely, tall fescue, orchardgrass, and timothy). They cannot be metabolised by enzymes in the foregut and are, instead, readily fermented by the microbial population in the equine hindgut. Therefore, they cause a response that’s similar to what happens when starch reaches the hindgut; they trigger acid production, a drop in pH, and a chain-reaction that might result in laminitis.
Their levels are typically higher in the seasons when the weather is ‘cool’: ie., Spring and Autumn. (They are still present during hot summers, but not usually at levels that will cause concern) and are also:-
· Higher in stressed pastures than in lush grass,
· Higher when night-time temperatures drop below 4 degrees Celsius (as the grasses do not grow, so the excess remains stored in the stems),
· Lower in the morning when days are sunny and nights are warm,
· Higher in the afternoon/evening on a sunny day,
· Lower in rainy, wet weather.
Fortunately, careful pasture management can help to protect your horse from potential health risks caused by high levels of fructans in grass (and excessive weight gain). The key is to build up time on grass slowly.
Some other tips are:-
1. Avoid Afternoon Grass
Fructan levels reach their highest in the afternoon on sunny days, so it’s best to turnout in the morning or late at night.
2. Maintain Pastures
Fructans levels are higher in pastures that are overgrazed or where grass is too mature. If you can, rotate pastures to give them a break, and/or keep them mowed to 4-8 inches (ideally).
3. Use Strip Grazing
Strip grazing and / or ‘track systems’ are a good way to restrict access so only a small amount of pasture can be consumed. This is particularly useful if you are away from your horses and can’t physically get them off the pasture. It also helps to manage weight-gain.
4. Use a Grazing Muzzle
Finally, consider using a grazing muzzle to limit the amount of pasture your horse or pony can eat in the time they are allowed access to pasture. (Some horses and ponies will not tolerate them, but if yours will, then they are a good way to restrict intake, as studies have shown that wearing a muzzle reduces pasture intake by approx. 75 - 80%).
Finally, if you are still struggling, then please do ask for help.