Time to Think About Winter Grazing

Richard Taylor, Extension Agronomy Specialist; rtaylor@udel.edu

Although it still feels like the middle of summer, now is the time to start thinking about those costly hay bills that occur over the winter months. One way to avoid these bills is to make use of a forage practice called fall accumulated forage. This practice can be used if you have pastures dominated by orchardgrass or perennial ryegrass for extending late-fall grazing, but the most versatile grass, and one that allows you to graze well into the winter months, is tall fescue. If a manager wants to fall graze pastures that are dominated by orchardgrass or ryegrass, grazing should be stopped at this point and 50 to 70 lbs of nitrogen (N) per acre should be applied. Grazing can begin in mid-October and should be completed by early to mid-December, depending on when winter temperatures arrive. The problem with these species is that they do not hold their quality very well after freezing temperatures arrive. To get the most from the fall accumulated forage, managers should employ rotational strip grazing (RSG) or management intensive grazing (MIG) in which the pastures are fenced off with temporary electric fence and only a day or two worth of grazing is offered to the animals at a time. MIG or RSG will reduce fouling of the forage by excreta and reduce the waste from trampling while helping to ensure the maximum intake possible.

There are some characteristics of tall fescue that come into play for winter accumulated fescue grazing. Currently, there are essentially four types of tall fescue in the marketplace or in pastures. The four types are: older, endophyte-infected Ky-31 tall fescue, endophyte-free tall fescue; novel or friendly endophyte tall fescue varieties such as MaxQ; and the new soft-leafed novel endophyte tall fescue varieties. New novel endophyte tall fescues are gradually coming into the market and will be available for future pasture plantings.

Those fields planted to tall fescue many years ago are most likely the older variety, Kentucky 31 tall fescue. Many of these older fields of Ky-31 tall fescue are infected with an endophyte fungus that produces alkaloids, anti-quality compounds that help the plant survive various stresses such as heat and drought better than fescue plants without the fungus. An endophyte fungus actually lives inside of the plant and grows between the cells of the fescue plant rather than inside the fescue cells. The fungus does not exist in the soil or outside the plant and is transmitted via the seeds of tall fescue. The alkaloids that the fungus produces also help the plant by affecting the grazing animals making it less likely the fescue plant will be heavily grazed and thus the plant will recover from grazing faster and have a competitive advantage over other grasses in the pasture. Having the competitive advantage is great for the fescue plants but the problems caused in the grazing animal (reduced weight gain, fescue foot, impeded blood circulation and poor temperature control in the extremities, and other conditions) are not advantageous to the livestock owner. When this type of tall fescue dominates a pasture, using the fall accumulated fescue technique will not significantly reduce the amount of alkaloid that the animals will be exposed to and so there will likely be impacts from the endophyte, including lower weight gains, even during winter.

If the pasture consists of mixed grasses with a predominance of long-established tall fescue but the manager has tested for the toxic endophyte and found the incidence level to be low, the pasture of an older variety of tall fescue can be used for fall-accumulation without the worry that the small level of endophyte present will cause a problem. In general, the level of toxic alkaloid in the forage goes down over the winter. The reduction helps some, but is not enough in the case of a high incidence rate to prevent problems as found in highly infected Ky-31 fields.

The next type is the endophyte-free tall fescue varieties. These can readily be used for fall-accumulated grazing without worry about possible alkaloids. The only concern the manager has with this type of fall fescue variety is that they do not survive as well as the fescue varieties infected with the toxic endophyte or with the novel, friendly endophyte. These endophyte-free varieties can be used, but should be managed more carefully to help prevent winter injury and stand loss.

The remaining types are the novel or friendly endophyte varieties. These varieties of tall fescue benefit from having an endophyte fungus associated with them but the fungus does not produce the toxic alkaloid that reduces animal performance and animal intake. These varieties are ideal for use in a fall-accumulated forage system since toxic levels of alkaloid are not present and since tall fescue has some fantastic characteristics that make it ideal for winter grazing. Accumulated tall fescue reacts to freezing temperatures by releasing sugars that encourages grazing animals to the point that they will dig through snow to find the forage. Not only does palatability improve during the colder months but the forage quality of the fescue declines very slowly during this time period. Fescue differs from orchardgrass, ryegrass, and the other cool-season and warm-season perennial grasses in that it maintains forage quality into the winter months.

If you’re considering using tall fescue for a fall accumulated forage system to reduce the need for feeding hay over the winter months, then choose the fields of fescue you want to use for winter grazing and cease any grazing now. You should quickly apply 50 to 70 lbs of N/acre to the fields and allow regrowth to occur. In mid to late October apply another application of N fertilizer (note that this differs from the discussion of orchardgrass and ryegrass above which only are fertilized once and will enter the grazing system by the end of October since their quality will begin to decline). The tall fescue pastures will be ready for MIG or RSG in early December and may have accumulated from 3,000 to 5,000 lbs of forage per acre that if managed carefully can stretch the grazing season into late January or even mid-February. The additional grazing time will help lower your hay bills as well as provide a healthier environment for your animals.

Happy Grazing!