Research by Bridgett Byrd (M.S., PhD candidate) at Virginia Tech, was used to create this graph. It shows that pastures at certain times of year have specific times of the day when plants contain high levels of non-structural carbohydrates (NSC). This is effectively mirrored by the insulin concentrations of the horses grazing on such pastures, in a similar way to the feeding of high starch and sugar diets. While this research has been available for the past few years, many horses owners have not been informed of the cumulative effects of long-term high-sugar diets on horses, particularly on sedentary recreational horses. (Graph and caption credit Virginia Tech.)Remember the image in that graph. We have just turned the calendars to March, so spring will soon be here and the time is here to start planning how horses will be managed on spring grass.
This year, thanks to increased educational efforts, many horse owners are seeking advice on how to avoid laminitis caused by spring grazing. Many horses suffer annual bouts of laminitis that can adversely affect the horse’s soundness for months, or may develop into serious chronic laminitis with its many problems.
Nutritional experts, however, caution that laminitis and insulin resistance are year-round problems and that a horse's entire feeding program should be scrutinized, not just the turnout on pasture.
The Waltham® Equine Studies Group, led by Dr Pat Harris MA PhD, VetMB DipECVCN MRCVS, offers this summarized explanation: “Turning certain ponies out onto lush pasture in the spring and autumn is a common triggering factor for the development of laminitis. It is currently thought that high levels of water soluble carbohydrates, (which include simple sugars as well as Fructan – the more complex storage carbohydrate) – and/or starch may be involved in this process.
"Previous research carried out in collaboration with Virginia Tech by the Waltham® Equine Studies Group in 2004 confirmed a link between insulin resistance and laminitis. This work demonstrated that a high starch and sugar diet, that causes corresponding peaks and troughs in glucose and insulin, increases the degree of insulin resistance.
Dr Harris continues: “The new revelations linking pasture directly to the potential risk of insulin resistance have important consequences for certain horses and ponies prone to laminitis and tying up, as well as obese animals that will already have a greater degree of insulin resistance. For these animals it is likely to be safer to feed alternative sources of forage at key times of year.”
Last month, Florida-based Seminole Feeds announced that it would no longer be the US distributor for Spillers brand feed products, which are developed with Waltham research principles. “Happy Hoof”, a high-fiber alternative to high-sugar hay, was one of the products sold by Seminole in the USA. Seminole has launched a new line of low-starch feeds under its “Wellness” label.
Maine-based Lucerne Farms, makers of the Dengie product lines of alfalfa-based chopped hay in the USA, is now offering high-fiber, low-sugar products for horses at risk for laminitis. The company also offers excellent customer support.
