– Neighborly Advice –
Grazing under pressure
Managing horse pastures during a drought
By Grey Parks, ProTrition Equine Nutritionist
As of this writing, most of our region is still experiencing levels of drought for the year. At present, it appears that we are in for a drier grazing season once again this year. Understanding how droughts affect your pasture and, by extension, your horses, will help you make management changes to preserve the health of both.
Most of our regionʼs pastures contain a mixture of cool-season forages, such as tall fescue, and warm-season forages, such as bermudagrass. Cool-season forages tend to go dormant during very warm, dry weather. Dormant plants, although appearing brown and dry, are not dead. The plants conserve energy by reducing or temporarily ceasing growth. Energy, in the form of sugar, is stored near the base of the plant to protect it during times of drought stress. Warm-season forages may continue to grow, although at a slower rate, even during times of drought.
Because most forages are not actively growing during a drought, they are highly susceptible to overgrazing. If horses graze the plants down to the crown or base, the plant may not retain sufficient energy stores to regrow once weather conditions improve. Additionally, overgrazed pastures result in thinly covered or bare spots of ground that are likely to be overtaken by weeds in short order. Avoid grazing forages below an average height of 4 inches to minimize the potential for damage.
Because most forages are not actively growing during a drought, they are highly susceptible to overgrazing.
ay appear safe for obese or insulin-resistant horses, this is not the case. Drought-stressed forages often contain higher-than-normal levels of sugars. Accumulated sugar is not the only potential danger to horse health associated with pastures during a drought. Certain plants may accumulate nitrates under drought conditions. While horses are less susceptible to nitrate toxicity than ruminant animals, pastures high in nitrates may cause digestive disturbances such as diarrhea or colic. Additionally, toxic weeds that horses would normally avoid may become more tempting when other plant material is in short supply.
It is important to limit your horses’ access to pasture during drought periods. If you have a dry lot large enough for all your horses, consider limiting the hours the horses are out on pasture and housing them in the dry lot for the remainder of the day. Alternatively, designate one pasture, or a portion of one pasture, as a “sacrifice area” and restrict your horses to only that area. A temporary fence, made of either corral panels or step-in posts and electric tape, can be quickly constructed and easily removed once the drought has ended. Supplement your horses’ forage intake by providing access to hay; this will not only reduce their pasture intake but also reduce their temptation to ingest potentially toxic weeds.
Protecting the health of both your pasture and your horses is important year-round, especially when weather conditions are less than optimal. Take steps to reduce damage from overgrazing now to avoid costly pasture renovations in the future. Visit your local Co-op for all your horse and pasture management supplies!