Given the prices of hay this past winter, I have been anxiously waiting for our spring pastures to make their appearance. Unlike my folks in Tennessee, we haven’t even mowed our yard yet. However, this last month proved to have just enough sun and warmth that I can finally look out and see a roll of green in our hay meadow.
The horses are gazing from their sacrifice lot towards the growing grass in the adjacent field and I am sure they are cursing the fence that separates them from heaven. However, I need to ensure I have a good 8 inch stand of grass before I turn them out. Any sooner, and I know I will hurt my overall pasture productivity for the rest of the growing season. In addition, we have had (knock on wood) some great spring rainfall. The ground is soft and the last thing I want is thundering hoofs digging up my pasture. Throughout the grazing season, I want to keep at least a 4 inch stand of grass in my pasture.
Don't start gazing your pastures until you have at least an 8 inch stand of grass. Photo curtesy of Dr. Krishona Martinson, University of Minnesota Equine Extension Program
Over or Under Eating
A pony or donkey, being smaller in size and requiring less energy, can easily become obese when given free access to grazing even a moderate-quality pasture. All equines utilizing pasture as their sole form of energy should have their body condition scores assessed frequently (every couple of weeks) to ensure they are not getting too fat or too thin. It may be important to limit grazing during times of lush growth such as early spring in order to prevent obesity or to supplement grazing with hay or grain during low pasture productivity, that is, in times of drought or towards the end of the grazing season.
LEARN MORE at eXtension.org/horses and take the HorseQuest Learning Lesson: How to Body Condition Score Horses.
A pasture should have at least a 4 inch forage stand to prevent over-grazing. Dr. Krishona Martinson, University of Minnesota Equine Extension Program
Grazing Muzzles
Grazing muzzles are very effective in limiting forage intake of both horses and ponies. The hole in the muzzle still allows for taking in small amounts of forage, it just cuts way back on the quantity of grass eaten per bite. While it may seem like a cruel joke to play, most behaviorist agree that it is indeed kinder and healthier to keep the horse on pasture with their buddies, versus keeping them up in a stall while everyone else is enjoying the pasture party. Horses can still drink water and the muzzle is safe to leave on overnight. When adjusting a muzzle to fit, follow the directions and check the horse or pony frequently to ensure the muzzle is staying on properly and is clean of debris.
Grazing muzzles allow horses that require limited grass to still enjoy grazing in the pasture.
Problems with Spring Pastures
If horses are kept on pasture year round, they usually adjust to the new foliage as it grows in the early spring. Most management problems occur when horses have been confined, fed a hay/grain ration, and then abruptly turned out to pasture in the spring. The lush spring growth of pasture foliage, either grasses or legumes, is high in moisture content (75-85%) but also relatively higher in protein, vitamins and minerals on a dry matter (DM) basis than during other seasons of the year. The energy and protein content of foliage can be as much as 50% higher in early vegetative growth compared to that in vegetative growth twelve weeks later. Horses kept in stalls through the winter and abruptly allowed free access to pasture might overeat because of the palatability of the lush green foliage. This over-consumption can put a horse at risk for certain nutrition-related problems.
1. Overweight/obesity – Depending on individual metabolism, some horses can gain significant weight on pasture alone.
2. Diarrhea - Higher moisture content and the change in ration can trigger a “loose stool.” The feces usually become firmer as the horse adapts to the pasture, but in some cases a horse must be confined temporarily and put on a hay-based ration to restore normal bowel function. In a small number of cases, a horse might require medical treatment to clear up the diarrhea.
3. Colic – Although colic is not common in these situations, any change in the ration if done rapidly can cause excessive gas or an intestinal upset in certain horses, leading to colic.
4. Founder (Laminitis) – Risk of this disease is always a concern when the ration is changed abruptly, especially when going from hay-based ration to pasture. Even though as a group, ponies are more susceptible to laminitis from early pasturing, horses are also at risk.
Laminitis (also commonly referred to as founder) results in a rotation of the hoof's coffin bone, rapid hoof growth and the separation of the lamina of the hoof wall.
Managing Spring Pastures
There are management practices that can prevent or minimize problems when introducing horses to pasture in the spring.
1. Restrict the grazing time. Allow horses on the pasture for 20 minutes the first day and increase the grazing time by five minutes per day over a two-week period until they have adapted to the new feed source.
2. Feed hay immediately before horses are turned out on pasture during the adjustment period. They fill their stomachs somewhat, thus helping to prevent overeating. This practice curbs their appetite and allows them to discriminate between appropriate pasture foliage and weeds. There can be potentially toxic weeds in some pastures and, if horses are very hungry, they may not be selective about what they eat.
3. Supplement grazing with hay. If pasture foliage is sparse, supplementing with hay might be necessary to provide sufficient energy and other nutrients. This practice also helps prevent consuming weeds because under some pasture conditions the weeds outgrow other foliage.
Supplementing the pasture with hay will help prevent overgrazing. Dr. Krishona Martinson, University of Minnesota Equine Extension Program
4. Avoid grazing early spring pasture. If a horse has a history of founder, avoid grazing in the first four weeks of spring growth; then follow Rules 1 and 2 when introducing a horse to the pasture.
5. Use a grazing muzzle. If a horse that is susceptible to founder must be turned out on pasture, use a grazing muzzle to limit pasture consumption.
