Yellow Grass – Is it really safe for Laminitics?

‍
Although parts of the UK have been blessed with some long awaited rain this week, the drought we have been experiencing has got many owners of metabolic horses and ponies wondering if their dry, yellow grazing is safe for their horse. For many, dry and seemingly sparse grazing can look like it has little to no nutritional value at all, but that might not always be the case.

While dry, mature grazing can be lower in nutritional value than rapidly growing, green grass, the colour and the appearance of the field alone cannot tell you how much sugar or NSC the grass contains. In some cases, ‘stress’ such as drought can cause some grasses to accumulate sugars. Research has found in some cases, drought 'stress' can increase the amount of WSC found in grass (Volaire, 1997).

In order to grow, plants need to photosynthesise and this requires carbon dioxide (CO2), water and light. When water becomes limited, however, the plant can’t keep photosynthesising normally. It’s a bit like having a factory that has plenty of power, but not enough raw materials coming through the door. So, during periods of water ‘stress’, the plant can accumulate NSC because the production/use and growth become out of balance. There are a lot of variables, however, and so essentially, stressed pasture is as variable as typical pasture and cannot be assumed to be ‘safe.’ The colour of the plant can indicate the maturity or stress of the plant, but it doesn’t give a reliable measure of sugar/NSC concentrations.

In addition, whilst your field may look sparse, it may not necessarily mean that additional calories or forage is required. If your horse is maintaining their weight and there have been no changes to the number of droppings produced in a 24-hour period, it’s likely they will be finding adequate fibre/grass from somewhere! Regularly body fat scoring your horse or pony in order to assess their calorie needs can be a great way of feeling changes before they become evident to the naked eye. For horses who really are on sparse grazing or for those on particularly sandy soil, offering additional fibre sources may be necessary. Providing forage which is raised off the floor (in feeders, for example) can help to reduce the risk of sand being ingested, as well as supporting fibre intake when grass is really depleted. However, remember to keep calorie intake in mind and soak or offer more mature forages if weight gain can be an issue.

What happens when rain arrives?

One of the biggest things to watch out for during a dry spell is the rainfall that eventually follows. Grass can respond relatively quickly to rain, and so the nutritional profile can change quickly with it. Restricting access and monitoring for signs of digestive upset are particularly important during these periods for those with an increased risk of laminitis.
‍

When it comes to laminitis management, the best approach is to manage the horse, not just the colour of the grass.

‍