Are you thinking about finishing cattle on grass? It can be done, but it does take some strategic grass management. Industry experts offer their best advice to get your cattle to the packer faster.
“We can finish beef on many kinds of forage, as long as it is grazed at an immature stage when it is leafy and high quality, with adequate density of stand that the cattle can take big bites,” says Dan Undersander, Extension and forage agronomist at the University of Wisconsin. “Cattle take about one bite per second and will graze for a few hours a day, taking 30,000 bites or so. If those are big bites and the forage is high quality, the cattle gain weight. If it’s 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 hotter, drier periods of the year. Brassicas like grazing turnips can be a high-quality feed but are much higher in protein than energy. They can be as much as 20% protein, which is more than these animals need,” says Undersander.
“Chicory is another good, high-quality forage. It is pretty good the first year but heads out the second year and is not as good. 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.”
He also suggests you have a strategy that keeps animal needs in mind when grazing various forages.
“In finishing grass-fed beef animals, we focus on two different things. One is to have a rapidly growing animal so we don’t have to keep it as long. Second, we want that animal at a certain weight with a certain degree of marbling,” Undersander says.
“If we can finish an animal at 18 months we have less investment than in one that takes 22 to 24 months or longer to finish,” he explains. In order to hit the efficiency goal, it’s important to manage the grazing so we can keep cattle eating high-quality forage, he adds.
“It is important for beef producers to understand the nutrient needs of growing animal because sometimes they are shortchanged in terms of pasture management,” adds Geoffrey Brink, research agronomist at the USDA-Agricultural Research Service, U.S. Dairy Forage Research Center in Madison, Wis.
“A pasture grazed at a more vegetative stage (young and growing versus mature) provides more energy—just because the fiber level of the plant is lower. While a growing beef animal will consume a more mature grass, the quality may not be high enough to produce much weight gain,” he says.
Mary Beth Hall, research animal scientist at the Wisconsin USDA research center, says it boils down to how much the animals can consume. “If forage is too mature, there is a limit to how much they can eat; it fills up the rumen [and doesn’t break down as quickly during digestion] and the animal can’t eat any more. So we look at how much they can eat, and factor in the composition of the forage to know whether the cattle are getting the necessary pounds of digestible nutrients and protein to support the performance we want,” says Hall.
Legumes are another type of energy-dense forage. “Many people include legumes in a pasture mix, particularly in perennial pastures. Some people overseed perennial or even annual legumes. In the South, annual legumes such as crimson clover are often used. In a temperate climate, red and white clover and alfalfa are utilized, which are all perennials. Legumes improve the digestibility and energy content of perennial pasture significantly,” Brink says.
Clayton Robins, Rivers, Manitoba, spent 22 years as a research assistant with Ag Canada in forage and beef production, and continues to do forage trials. He has traveled to many regions around the world that practice longer grazing than we do, with more emphasis on assessing plant sugars and other forms of metabolizable energy in the plant.
“In North America, we tend to focus more on fiber. I looked at some of the plants other countries were using, and the influences those plants have on ruminant digestive efficiency—and the ability to initiate early development of marbling cells in young, developing animals,” he says.
Most studies on marbling have been done with early-weaned calves fed high-energy diets, but Robins feels we might be able to get that same effect with grazing. “We could do this while a calf is still on the cow—rather than feeding grain or some other high-energy supplementation. It does require a sustained supply of high levels of energy to trigger the phenotypic and physiological responses,” he explains.
“Researchers in other parts of the world have come to the same conclusion. Trials in New Zealand, for instance, are using energy-dense forages to determine that potential. These studies are assessing early-weaned calves on forage instead of concentrates/grain, and evaluating impact on carcass quality and earlier time of slaughter—with the expectation of improved marbling,” Robins says.
“We did a lot of work with swath grazing at the Brandon Research Centre, including trials looking at understory crops. I continue to try new plants we hadn’t considered when we began. Currently, I am using tetraploid Italian ryegrasses [which can accumulate the greatest amount of plant sugars] along with chicory and forage plantain, as well as few legumes.”
He is trying to create a crop of annuals that will grow all year. “Normally we look at swath grazing, silage or cereal grain as about 75 days of active growing. I am planting that same crop, but adding an understory of ryegrasses, chicory, plantains and clovers, and might also add festoliums, then early harvesting the cereal and leaving it in the field.”
He used small square bales, but wants to try wrapped round bale haylage. “We leave bales in the field for cattle to utilize later, and let the understory crop regrow for later grazing,” he explains. The field can be strip grazed, opening the bales instead of having windrows. The baled forage holds quality.
These plants have all been looked at before, in Canada and the northern U.S, but their potential was largely abandoned because they wouldn’t overwinter. “We were always focused on longevity, which is important when we want plants that grow every year. But if we can utilize them as understory crops to go with cereal harvest, with lots of yield, we can achieve greater carrying capacity per acre and the potential gain per acre is very high. If we can initiate early-marbling cell development—which might take time off the end point for finishing/feeding—the economics start to look very good. Then the cost of annual seeding becomes almost inconsequential,” he explains.
“If we have plants that contain 30% sugar in October, we can do a lot with them. My strategy is to look at August, September and October as a three-month grazing window.” If they can find a high-quality overstory cereal crop, it becomes attractive.
“With my cattle at home, I can carry 70 steers on an acre for 3 to 3.5 days. If we can push the gain higher, with that kind of carrying capacity, numbers start to look very good economically. We need to look at animal performance data and eventually see what we can do in terms of physiology in the animal as well. This provides some alternatives for beef production rather than just feedlot finishing,” he says.
Smith Thomas is a rancher and freelance writer based in Salmon, Idaho.