Grazing Muzzles
The horse has evolved as a grazing animal hence pasture plays a pivotal role in equine nutrition. Reported intakes of fresh pasture by horses can range from 1 5 to 5 2 percent of body weight per day. With such a large intake of pasture possible can horses overconsume? What components of pasture grass can cause problems if taken in at excessive levels?
Whats in the grass?
Pasture has been implicated in the onset of several metabolic disorders in horses. During photosynthesis green plants fix atmospheric carbon dioxide in the presence of light resulting in the production of simple sugars. When sugars are produced in excess of the energy requirement of the plant for growth and development they are converted into storage or reserve carbohydrates. These carbohydrates make up the nonstructural carbohydrate NSC fraction of the plant. These nonstructural carbohydrates follow a seasonal pattern with highest values in spring compared to summer and winter and intermediate values in the autumn. The overconsumption of nonstructural carbohydrates by grazing horses have been implicated in disorders including insulin resistance and laminitis.
In addition to nonstructural carbohydrates causing metabolic issues the sheer overconsumption of pasture grass can cause obesity in horses. Obesity can result in further problems with insulin sensitivity as body fat mass increases. All of these overweight conditions result in a cascade of problems that at the very least leave your horse fat and intolerant of exercise to far more severe conditions such as insulin insensitivity and laminitis. It has been reported that excessive pasture intake accounts for nearly 50 percent of all reported cases of laminitis. Obesity therefore must be corrected.
First step is calorie control
The first step in any weight reduction program is calorie control. Elimination of all grain from the diet is a logical step for overweight horses. A
