ENERGY-DENSE FORAGES BENEFICIAL FOR WINTER GRAZING

by: Heather Smith Thomas

Some forage species are more energy-dense than others, containing higher levels of sugars. Beef producers around the world have been utilizing some of these species in grass-fed beef production, using forages instead of grain for finishing beef animals. Some of these forages can also be beneficial in a fall/winter grazing program.

Dan Undersander, Extension and Forage Agronomist, University of Wisconsin, says ryegrass is one of the most energy-dense grasses and used all over the world and in parts of the U.S. “The main issue with ryegrass would be that it lacks winter hardiness. In the northern half of the U.S. it will die out most winters and would therefore need to be replanted annually. In the southern half it can persist and be a perennial forage. In the tier of states along the Canadian border it would be an annual, however,” he says.

“Ryegrass is the single forage that is higher in quality than anything else. The ryegrasses are actually a continuum, varying in energy density from the Italian (with the highest sugar levels) which some people call annuals, to the perennials, and then there are crosses between the two. We generally think in terms of the diploids for grazing and the tetraploids for hay-making. Tetra means it has 4 copies of every gene,” he says.

“There is some work on these tetraploids in England, developing some high sugar types, but I think we can finish beef on pasture whether or not we have these high sugar types. The main thing is to have adequate forage and graze it at an early stage of growth when the nutrient levels are highest,” says Undersander.

You need a type of forage that will grow well in your climate. “Annual ryegrass is ideal, but we can produce good beef on pasture with perennial forages like tall fescues and orchardgrass. The main thing about ryegrasses is that they need a cool, wet environment; they are not appropriate for hot or arid regions. In those environments we have several other choices,” he says.

“In looking at annuals, the sorghum/sudan grasses are a good choice for finishing cattle, particularly the brown midrib types. These are annuals that will grow in warmer weather. They are not the best choice in northern states but work well in southern climates,” he says.

“In order to get good productivity for these grasses, however, we need 20 to 30 inches of water annually. They would be most appropriate for the wetter regions of the West, Midwest and South, or for irrigated pastures. In dry land across the West where we have less than 20 inches of rain, we'd probably look more at permanent pasture and some of the range grasses. We can do some nice finishing of beef on buffalo grass, which is a short-growing perennial grass on the high plains of Texas and Oklahoma. The best species to use will vary from region to region. The main thing is use species that are adapted to the local environment and then harvest or graze them at an appropriate stage when they are high in quality,” he explains.

The crosses between ryegrass and fescue can work in some regions. “These are a festolium. There is a new one coming out right now that may be beneficial. Festoliums are a little bit more winter-hardy than the ryegrasses, but not a lot,” he says.

“The Wisconsin Grazers are now producing seed from a new variety of meadow fescue called Hidden Valley, which has most of the traits of ryegrass but has the winter hardiness and drought tolerance of the meadow fescue. Meadow fescue will survive winters in cold climates,” says Undersander.

“Where we need a lot of winter hardiness is usually not right at the Canadian border but just a little bit more south. The areas that have good snow cover most of the winter are better because the snow protects the over-wintering plants. They can survive more readily than in an area where the snow comes and goes,” he explains.

“Across Minnesota and Wisconsin we generally need more winter hardiness for plants in the southern edge of these states; we can utilize plants with less winter hardiness as we go north. In central Wisconsin we can get festoliums to survive for three or four years, while in southern Wisconsin they've never survived more than one year,” he says. Winter hardiness is a key thing when selecting forage plants in some regions.

“Regarding finishing grass fed animals on forage, we can finish beef on many different kinds of forage, as long as it is grazed at a stage when it is leafy, immature and high in quality, with adequate density of stand that the cattle can take big bites. Cattle take about one bite per second and will graze for a few hours a day. They'll take 30,000 bites or so. If those are big bites and the forage is high in quality, the cattle will gain weight. If they are small bites and/or low in quality, then they won't finish as well,” he explains. There are some perennials and some annuals that work nicely for finishing.

“The brown midrib sorghum/sudan grass would be the counterpart to ryegrass for the hotter, drier periods of the year. The brassicas like grazing turnips can be a high quality feed but they are much higher in protein than in energy. They can be as much as 20 percent protein, which is more than these animals need. They do best in a cool and wet environment and not so well in a hot, dry climate,” says Undersander.

“Chicory is another good high-quality forage. It is pretty good the first year but heads out in the second year and is not as good quality. You might use it the first year for finishing animals and the second year for younger growing animals that don't need quite such high quality feed.” A person needs a strategy that keeps the animal needs in mind when grazing various forages.

“In finishing grass fed beef animals, we need to focus on two different things. One is to have a rapidly growing animal so we don't have to keep it as long. Secondly we want that animal at a certain weight with a certain degree of marbling. If we can finish an animal at 18 months we have less investment in that animal than one that takes 22 to 24 months or longer to finish,” he explains.

Regarding forages, the plants must be high in nutrients. “Pasture density is important, so animals can get big bites. We need to manage the grazing so that we can keep cattle eating high quality forage.”







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