Cattle grazers all across Canada have a wide choice of perennial forage species that they can seed this year. But how do producers pick a species and variety to grow in their respective areas?
The question of seeding in mixtures has always been a puzzle. In the 1960s and early 1970s, seed mixtures contained 17 different grasses and legumes. It was a shotgun approach and over the years, these old pastures wore down to low-producing bluegrass stands and little else.
Currently, all sorts of research is being done in Canada on perennial forage mixtures. Agriculture and Agri-Food Canada researchers, with financial help from the Beef Cattle Research Council, have come up with new blends of grass and legumes that could offer richer pastures for beef cattle.
In Nova Scotia, Yousef Papadopoulos and John Duynisveld at the Nappan Research Centre are looking at mixtures to grass-finish beef cattle.
“Farmers often plant recommended varieties designed to produce hay, but are not good for grazing. They’ve been selected for a hay production where they’re harvested two or three times a year and they don’t have the pressure of animals grazing on them,” Duynisveld says.
Papadopoulos, a plant breeder, has compared the growth or yield to the energy and protein in the pastures.
“The highest yielding binary mixtures were white clover and Courtney tall fescue; birdsfoot trefoil and Kokanee tall fescue; alfalfa and Kokanee tall fescue; alfalfa and Express timothy or birdsfoot trefoil and Arctic orchardgrass. The ultimate goal is to offer farmers a pasture that will allow them to keep their cattle grass fed, and avoid the additional expense of sending cattle to a feedlot before slaughter. Keeping cattle in fields longer can save farmers money.”
Gilles Bélanger at Agriculture and Agri-Food Canada in Quebec City says there is a lot of interest in their region for finding a replacement for timothy. Timothy has poor regrowth and will not take advantage of a longer and warmer growing season with climate change. As well, timothy does not respond well to the intensive cutting management used by dairy farmers.
“In an effort to increase forage quality we are looking at tall fescue, meadow fescue, festulolium, perennial ryegrass, and meadow bromegrass, mostly in a mixture with alfalfa. We are also collaborating with our colleagues at Université Laval to compare feeding timothy and tall fescue to dairy cows. Tall fescue has a bad reputation for intake. So we are trying to answer some of those questions.”
The Quebec team is also looking at the ratio of available energy to protein in forages as a means of increasing the efficiency of nitrogen use in dairy cows and milk production. Their efforts focus on increasing the ratio of non-structural carbohydrates or sugars to rapidly degradable protein through cutting management and species selection. The research shows the choice of species in the mixture does affect this ratio. For instance, meadow fescue with alfalfa produced the highest ratio of readily available energy to crude protein in a study comparing 18 grass-legume mixtures.
Mike Schellenberg at the Ag Canada, Swift Current Research and Development Centre found seeded mixtures increased forage production, resilience to negative weather events and below-ground diversity which has been related to improved soil health.
“Some of our initial work has also identified improved forage production with more than a single legume species” he says. “Having an early-season legume such as alfalfa growing with a late-season legume such as purple prairie clover provided the best yields and highest quality forage.”
“Higher productivity is found with legumes present. In our case, we started with 50:50 of alfalfa to purple prairie clover. To allow for other species to remain in the forage mixture, the recommendation is to have less than 30 per cent wheatgrass. Post-seeding management will also determine what will remain in the stand.”
Native plant mixtures are another focus of BCRC funded research at Swift Current, Lethbridge, Saskatoon and Brandon, including the development of native plant materials for seeding into pasture and rangelands at Swift Current. Species moving toward commercialization include northern wheatgrass, rough fescue, prairie sand reed grass, winterfat and white and purple prairie clovers. The white prairie clover is furthest along.
“The prairie clovers have interesting condensed tannin profiles that help prevent bloat and have anti-microbial characteristics,” says Schellenberg.
A few new grass varieties have been developed in recent years through Bruce Coulman’s breeding program at the University of Saskatchewan in Saskatoon. Armada meadow and AC Goliath crested wheatgrass showed high forage yield in multiple location trials. AC Success is one of the only two hybrid bromes developed in Canada. It showed high forage yield, and relatively good regrowth.
In future, Bill Biligetu at U of S will be developing locally adapted alfalfa and sainfoin varieties that will have high yield and persistence under local environment and will include winter hardiness, disease resistance, and tolerance to intensive grazing.
Alfalfa’s nitrogen-fixing capacity and the ability of its deep roots to prevent wind and water erosion makes it a common ingredient in mixed-species improved pastures. Alfalfa can sustain high levels of production in pastured cattle, but its propensity to cause bloat discourages its inclusion at high seeding densities.
“Condensed tannins in legumes are responsible for their bloat-safe nature,” says Tim McAllister, a researcher at Lethbridge Agriculture and Agri-Food Canada. “Alfalfa only produces the condensed tannins in its seed coat, whereas other legumes such as birdsfoot trefoil, cicer milkvetch, purple prairie clover and sainfoin produce condensed tannins within the foliage. In addition to preventing bloat, condensed tannins improve ruminal nitrogen utilization, control intestinal parasites, reduce Escherichia coli in feces and possibly reduce methane emission.”
Along with plant breeder Surya Acharya the Lethbridge team has been using sainfoin to develop high-performance grazing systems by growing it in mixed stands with alfalfa.
“Among the condensed tannin forages, sainfoin is the most adaptable for use in a high-performance grazing system in mixed stands with alfalfa,” says Acharya. “It has high nutritive value, winter hardiness, drought tolerance and resistance to some alfalfa insects. It is well adapted to dry and calcareous soils and grows best on deep soils with a pH above 6.0. Sainfoin is comparable to alfalfa in nutritional quality and results in average daily gains in cattle that are similar to alfalfa.”
Sainfoin produces higher daily weight gain compared to other condensed tannin-containing legumes such as birdsfoot trefoil. Sainfoin also retains its leaves longer than alfalfa and can be harvested at a more mature stage without a loss in quality, with the highest yields obtained at 75 to 100 per cent bloom. As little as 10 per cent sainfoin in alfalfa pastures can dramatically reduce the risk of pasture bloat.
As for bloat-free alfalfa grazing, he recommends establishment of sainfoin and alfalfa mixed stands in alternate rows using the new multi-cut-type AAC Mountainview sainfoin. Seed 15 pounds of Mountainview sanfoin and five pounds of alfalfa in alternate rows without grass. Other single-cut-type sainfoin cultivars will not provide bloat protection in mixed alfalfa stands due to the lack of regrowth.
Yuxi Wang, an expert in condensed tannin chemistry at Lethbridge, is looking at including purple prairie clover, a legume with unusually high levels of condensed tannins that is native to North American grasslands, into high productivity grazing systems. Purple prairie clover is highly digestible and has properties against Escherichia coli O157:H7 and lowers the levels of E. coli shed in cattle feces.
Bart Lardner with the Western Beef Development Centre at Lanigan, Sask., and Alan Iwaasa at Swift Current are evaluating the effects of grazing, forage yield and quality on animal performance. “We are looking at different forage binary mixtures of Mountainview sainfoin or Yellowhead alfalfa, a very persistent alfalfa seeded with AC Success hybrid bromegrass or Tom Russian wild ryegrass for August-September, October summer-fall grazing period,” says Lardner
“We are also evaluating a number of legumes: white prairie clover, purple prairie clover, Canada milkvetch, and Veldt cicer milkvetch developed from AAFC-Lethbridge,” says Iwaasa. The grasses are Admiral meadow bromegrass, Tom RWR and AC-Success. These legume+grass binary mixtures are being evaluated at both Swift Current and Lanigan. In addition, at Swift Current on small plots, they are evaluating the newest sainfoin varieties Shoshoe and Delaney from the U.S. and Canada’s AC-Mountainview and Nova and another RWR, Bozoisky II.
“We are evaluating them for forage quality and stand longevity in binary mixtures for extending the grazing season,” he explains.
Don Thompson, a rangeland research scientist at Lethbridge, says introduced grasses are often cited as more productive than native grasses. However, if the seed quality of native grasses was improved, he thinks they would establish as well as introduced grasses and yield as well, too. The main factor holding native stands back is reduced productivity due to poor establishment which reduces stand density.
Thompson says western wheatgrass and little bluestem are the most promising native grasses for forage production.
“It was interesting that a warm-season grass like little bluestem may be well adapted for late-season forage production well beyond its normal range of occurrence,” he adds.
“Mixtures of these grasses with purple prairie clover have more stable yields and improved nutritive value. One idea is for producers to establish separate pastures for early and later summer grazing. The early-season pasture could be western wheatgrass and the late-season pasture could be little bluestem with purple prairie clover. We observed that due to its rhizomatous nature, western wheatgrass tends to dominate when seeded in a mixed stand. One study at Swift Current and Lethbridge showed that green needlegrass was as productive as western wheatgrass but may be a more suitable cool-season grass for grass-legume mixtures.”
“In British Columbia, bluebunch wheatgrass is well adapted to the mid-summer drought in the Interior and two new bluebunch wheat grass varieties are being developed for use in British Columbia.”
For additional information on seeding forages go to foragebeef.ca.