Ask the Expert: Grazing a Newly Seeded Pasture

Question: This spring, we planted 2.5 acres of pasture for our horses. The grasses are now 6 inches tall and the stand density appears good. Should we mow the pasture? If so, how often? When should we start grazing?  

Answer: You will want to mow the pasture 3 times before allowing the horses to graze. Since the grass is 6″ tall, mow it down to 3″ and allow it to re-grow to 6″, then mow again. Follow this cycle until you have mowed the pasture 3 times. This is critical since new grass seedlings need time to firmly root into the ground. Mowing helps to stimulate root growth and anchors the plant without the physical pressures of grazing. If the pasture is grazed too soon, horse can pull new grass seedlings out of the ground. Mowing will also help control some weeds that are common in new pasture seedings.

Once you have mowed 3 times and the grass has regrown to 6″, you can start grazing the horses. If the horses are acclimated to pasture, they can be allowed to graze until the pasture is, on average, grazed down to 3″. At this time, you would rotate the horses off the pasture, mow the pasture to 3″, allow the pasture to regrow to 6″, then graze again. You would keep repeating this process until the pasture stops regrowing in the fall; it is critical to allow the pasture to rest and regrow. Unfortunately, horses do not graze uniformly, so mowing is necessary to ensure the pasture regrows evenly, plus mowing will help control some weeds.

If your horses are not acclimated to pasture, then start grazing in 15 minutes increments, adding 15 minutes each day until you reach 5 hours of consecutive grazing. For example, 15 minutes on day 1, 30 minutes on day 2, 45 minutes on day 3, etc. This allows the horses to slowly acclimate to pasture and reduces the risk of laminitis and colic that is often seen with abrupt diet changes.

Along with mowing, make sure to drag manure piles 2 to 3 times a year during hot and dry times, fertilize as needed, and control weeds. For more information on pasture management, click here.  

Written by Krishona Martinson, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.

Pasture Management – How to Prepare for Fall

Managing pasture can be a very important tool in controlling feeding cost for all livestock, including horses being kept on small acreages.  If pasture is going to provide a substantial amount of the required nutrition for a horse, it takes about 2-3 acres, per 1,100 pound adult horse.

Even with adequate acreage, weather conditions can limit pasture regrowth and decrease the amount of forage available.  Avoiding over-grazing is important for both the pasture and for the animals.   Keep the following in mind:

  1. Remove animals from the pasture when plants are grazed down to 3-4 inches in height. Grazing  too long and allowing animals to eat the grass off too close to the ground, will kill the grass and turn the pasture into a dirt lot where the only green plants are weeds, potentially requiring expensive renovation.   Also, if animals eat the grass too close to the ground on sandy ground, the risk of sand colic may increase.  Animals may also consume potentially toxic weeds if no other forage is available.
  2. If you have limited acreage, consider purchasing some temporary fencing so that you can rotate the pasture. The outer fencing should be a safe, permanent fencing.  You can cross fence the pastures with temporary fencing such as capped steel posts and appropriate electric wire.  By allowing the animals to graze one section, then moving them to another, total pasture yield can be increased substantially, helping to control total feed costs and improve pasture health.  Clip and drag the pastures after you pull the animals off to control weeds, parasites and flies.
  3. As pasture declines, you will need to adjust the amount of forage that is offered to maintain dry matter intake and nutrient intake. If the forage available is lower protein and lower energy than the pasture has been, you may have to adjust the concentrate portion of the diet. If you are using a ration balancer, you may need to move to the higher feeding rates.  If the higher feeding rates do not maintain Body Condition Score and Topline Score, you may need to switch to a different feed to allow higher feeding rates.  It is essential to monitor both Body Condition Score and Topline Score.
  4. Declining pasture quality can be a particularly serious issue for young growing horses, pregnant mares and senior horses.
  5. Make certain that fresh clean water is available at all times and that salt is available at all times. If you are not feeding a balanced feed or ration balancer, offer appropriate mineral free choice as well.
  6. If space is very limited, keep a dry lot area where animals can be fed and watered to prevent areas of pasture from being overgrazed.

Managing the pastures and selecting the right feeds as pastures change can help manage total yearly costs as well as improve animal health and condition.