Pasture & Range: September 2002

In cow-calf production, 65 percent of the cost of producing calves can be attributed to feed. These feed costs fluctuate widely depending on if the feed is harvested, stored and fed to animals or if they are allowed to harvest feed for themselves. Table 1 illustrates this concept, and while these data go back a few years, the point is still very valid.

As the table shows, it is at least 50 percent more cost effective for animals to supply their energy needs through grazing than with alternative means. Fall and winter are often two of the most, if not the most, challenging times to provide nutrients to the cowherd. Bermudagrass pastures are dormant and supplement typically needs to be fed or a cool season annual pasture established. An alternative source of nutrients can come from the stockpiling of tall fescue, if available. Producers all across the upper Midwest, Southeast and other portions of the country where tall fescue is productive have a love-hate relationship with it. Producers who have it wish they could find another cool season forage grass to take its place; those who don't have it wish they did. In terms of its design, it is an extremely rugged plant that is persistent under continuous grazing (in areas where adapted) and is high yielding with good quality. Putting the words "good quality" in the same sentence with tall fescue may raise a few eyebrows, but in Feeds and Feeding by Cullison, the dry matter crude protein value of fresh tall fescue forage is listed at 12.4 percent with a total digestible nutrient (TDN) value of 65 percent. It is the anti-quality factors associated with tall fescue that give the grass its bad reputation.

Tall fescue can be infected with an endophyte fungus which produces alkaloids that can have toxic effects on grazing animals. Those toxic effects include elevated body temperatures, rough hair coat and depressed weight gain (tall fescue toxicosis). These effects are usually seen when temperatures are higher than 85 degrees F.

Despite its shortcomings, tall fescue is the ideal cool season grass to stockpile for winter grazing. It has a waxy cuticle layer on its leaves that preserves and protects the plant late into the winter. As temperatures cool, tall fescue accumulates soluble carbohydrates in the stems and leaves, adding to its quality. Tall fescue is also very responsive to nitrogen fertilizer, and high yields can be achieved with timely N application.

Stockpiling tall fescue takes planning and preparation. Good quality, stockpiled tall fescue is not an accumulation of spring growth. Good quality stockpiling of tall fescue begins with new, fresh growth 60 to 90 days prior to the end of the growing season with the application of nitrogen fertilizer to achieve the approximate yield desired. At the Forage Systems Research Center in Linneus, Mo., the timing of N application and yield response of tall fescue has been studied (Figure 1).

Figure 1.

As Figure 1 shows, the earlier you begin in the season, the more accumulated yieldwill result. However, the longer the stockpiling period, the lower the quality will be, since there will be death of the lower leaf area. By delaying the onset of stockpiling, quality will be higher but yield will not be as great due to fewer days in the growing season. The source of nitrogen depends upon cost and availability. If used correctly, all sources of nitrogen will produce similar yields.

To take full advantage of the stockpiled forage, it should be strip grazed. If not, the forage will be underutilized because as cattle walk and trample tall fescue during cold weather, it breaks the waxy cuticle layer and causes rapid deterioration.

The quality of properly stockpiled tall fescue can be good, with crude protein levels running 12 percent or higher. Fescue toxicosis effects are not as prevalent in the fall and winter with cooler temperatures and decreasing ergovaline levels, but they can still occur. There are new tall fescue varieties becoming available which contain a novel endophyte that does not cause fescue toxicosis. Hopefully, these new endophyte varieties will be as persistent as old endophyte varieties like Kentucky 31. These new fescues should stockpile as well as old varieties.

A stockpiled tall fescue system works well for mid- to late-gestation cows and, with a cost of approximately $0.02 per pound of dry matter, it makes cheap forage. With margins as tight as they are, there is nothing wrong with good, cheap forage that you can watch the cows harvest rather than having them watch you harvest.