Rotational horse grazing, one option to consider for pasture managementWritten by Natasha Wheeler
Although rotational grazing is a concept familiar to many cattle producers, it is not used as commonly in horse management, according to Laura Kenny, program associate in the Department of Animal Science at Rutgers University.
“The grazing system we are most familiar with that most horse farms use is a continuous grazing system. To define this, I would say that horses have regular access to an entire grazing area,” she explains.
Continual grazing challenges
Some of the potential challenges with this kind of system include overgrazing and uneven grazing.
“The horses will eat everything that is out there, and we’ll see stubble. Once the grass starts to grow back to about one or two inches tall, it’s full of sugar. It tastes great to these horses, and they are going to go back and eat it over and over again,” she explains of overgrazing.
This will eventually lead to bare ground, followed by the invasion of weeds.
When uneven grazing takes place, horses eat only the grasses that are more palatable, leaving less desirable grasses behind.
“The grasses they don’t like as much are going to grow taller, more mature and more fibrous. Then they are going to be even less palatable, so we will see big areas of grazed and un-grazed areas, and it’s not very efficient,” she continues.
Problems with compaction, erosion and mud can also be challenges in continuous grazing systems.
“Another system that can be used is rotational grazing. The key point in this system is that the pastures get a chance to rest. We graze them for a short period of time and allow the forage to regrow,” states Kenny.
To allow for the horses to have a continuous source of forage, they must be rotated through a series of pastures while the grasses recover. In an ideal situation, describes Kenny, the first field will be ready to graze again once the horses have been through all of the other fields.
“Of course, this doesn’t always work,” she notes, explaining that each individual farm will have to determine grazing periods, resting periods, stocking rates and other factors depending on their own unique situation.
“In what I consider to be a traditional pasture, we have a perimeter fence around the outside of the pasture, a gate leading in, a shelter and water. To turn this pasture into a rotational grazing system, we can create a stress lot, also known as a dry lot, in the middle of the space,” remarks Kenny.
In a radial design, a stress lot is created around the shelter and water, allowing full-time access for the horses. The surrounding pasture is then divided into separate fields, with gates than can be opened and closed to the stress lot.
“The horses will always have access to the stress lot, no matter what field they’re in. In this system, once the grass is six to eight inches tall in the first field, we will put the horses in and open the gate to the stress lot, but close the gates to all of the other fields,” she describes.
Once the grass has been grazed down to three or four inches in height, the horses will be moved to the next field, using the gate system to contain them to the correct areas.
An alleyway system can also be designed to create the same kind of system if the shelter and water source are not located in the center of the pasture.
“Mowing also helps us with the uniformity of grazing, so if there are tall areas that haven’t been grazed, mowing will keep the vegetation in a nice leafy vegetative state and not allow it to go to seed,” she adds.
Mowing also helps reduce unwanted weeds and improve uniform grazing, as different grass varieties will be kept at the same height.
“We can do rotational grazing on a more intensive scale in the same field,” Kenny continues, describing how the pasture is divided into more subplots than a less intensive system.
“One benefit to more intensive grazing is that the horses will graze the subplots more uniformly because there is less forage,” she continues.
However, one of the disadvantages can be increased management, such as more frequent field monitoring and rotating horses between pastures more often.
Kenny also notes that there may be times when the horses should be retained to the stress lot.
“These would include very wet weather when the horses will tear up the ground when they are outside, very dry weather when grass plants are going to be very vulnerable and can easily be damaged by horses’ hooves or early spring and winter when we don’t want to have the horses out because they will ruin the pastures,” she says.
Stocking rates are another important consideration when designing rotational grazing systems to ensure that all of the animals are getting adequate nutrition.
“We want to keep 70 percent vegetative cover at all times,” suggest Kenny.
If pastures are overstocked, keeping horses in the stress lot with hay may allow the pastures to recover, and if pastures are under stocked, mowing may be required to maintain a healthy, nutritious grass height.
“If we are considering a rotational grazing system on our farm, we have to be flexible,” she continues.
Factors such as seasonality and weather can impact the availability of forages in the given pastures.
“We need to plan ahead. In case of a drought, we need to have hay on hand in case the horses need to stay in the stress lot for an extended period of time. We have to be willing to monitor and willing to adjust that original plan,” adds Kenny.
She also suggests keeping good records so that, over time, producers can determine the best stocking rates and grazing patterns throughout the year.
“Managing grazing is only a small piece of the pasture quality game. Other important factors of maintaining pasture quality include fertilization, controlling weeds, creating exercise areas and paddocks and considering the need for reseeding or complete renovation once the pasture plants start to decline and produce less forage for our horses,” remarks Kenny.