BCRC: Fear of bloat costs more money than actual cases of bloat do
High protein forage can increase rates of gain, benefit soil
Editor’s note: The following is part 1 of a two-part series. Stay tuned for alfalfa grazing tips from cattle producers from across the country in part 2.
Respect it, but don’t fear it. That’s the message from cattle producers and beef specialists alike who through years of experience and research appreciate the value of grazing cattle on pure or percentage stands of alfalfa.
Properly managed alfalfa makes good pasture with several added benefits, including:
- Improved weight gains on all classes of cattle (gains of 1.5 to 2 or more pounds per day can be expected);
- adding fertility to the soil with a nitrogen-fixing crop;
- creating a hedge against poor forage production during dryer growing seasons; and
- increasing plant biodiversity to benefit soil health.
Yes, there are circumstances when turning cattle into a lush stand of alfalfa at the wrong time and perhaps with the wrong class of cattle can result in bloat. But paying attention to a few production and management principles can greatly reduce the risk of bloat and provide producers the opportunity to capture the benefits.
While pure stands of alfalfa pasture can be very productive, they may be more appropriate for end use as high quality hay or silage for dairy cattle. From a beef cattle grazing perspective, most interest these days is in 30 to 60 per cent alfalfa grown in a blend with grass forages and/or in combination with other legume species.
“We’ve looked at alfalfa in several different grazing studies over the years, most often used in a binary mix (alfalfa/grass forage blends),” says Bart Lardner, formerly research scientist at the Western Beef Development Centre, now a professor in the Department of Animal and Poultry Science at the University of Saskatchewan. “And the alfalfa component produces several benefits. The industry has lost a lot of money over the years by avoiding alfalfa, partly due to unwarranted fear.”
Timing is one of the keys to reducing the risk of bloat, says Lardner. In high percentage alfalfa stands avoid grazing alfalfa before and up to the bud stage, when plants can be lush and tender. And avoid introducing cattle to an alfalfa pasture when the dew is heavy or while it is raining. As plants mature and develop more fibre, the risk of bloat greatly decreases as the stand reaches 30 to 40 per cent flower stage. And including alfalfa in a pasture forage mix that includes more fibrous grasses also provides cattle with a wider feed selection than just straight alfalfa. “It may take some experience for people to find their comfort level for grazing alfalfa, but it is an excellent forage,” he says. “Yearlings will gain nicely on alfalfa with no comparison to a grazing straight grass.” (See accompanying list below for more tips on alfalfa grazing management).
Lardner says a legume/grass pasture blend that includes about 30 to 40 per cent alfalfa makes excellent pasture for grazing cow-calf pairs. “It provides good quality forage for the nursing and gestating beef cow, and can help increase weaning weights on calves,” he says. “And the legume is also helping to fix nitrogen in the soil.”
And for backgrounding cattle or grassers, studies show a pasture with a 50/50 blend of alfalfa and grass species can generally produce 1.5 to 2 pounds per day or more weight gains.
Lardner says studies over the years have involved several alfalfa varieties with some differences in production, but all performed well. AC Grazeland BR, for example, is a bloat-reduced variety that showed reduced yield compared to conventional alfalfa varieties in some projects, but still had adequate quality for beef cattle. Spredor 4, a grazing-type, fall-dormant variety with some yellow flowering, also worked well in cow/calf pasture trials.
A newer variety PS3006, is a creeping-rooted variety used in grazing trials comparing different forage legumes and grasses in the blend. And AC Yellowhead, an older yellow-flower Siberian variety, was another one used in blends along with other forage legumes and grasses.
“One of the neat things about alfalfa is that there are so many varieties — some with purple flowers and others with yellow — which have tremendous potential for adaptability to Canadian growing conditions,” says Lardner. “Many varieties have tremendous tolerance of high pH soils and salinity with good production.”
Creeping rooted alfalfa varieties generally survive for long periods of time, but management has a significant impact on their longevity. Cultivars of creeping root varieties have varying levels of winter hardiness and disease resistance, higher yields in dry weather, salinity tolerance, and tolerate soil pH as low as 6.2. Tap-root type alfalfa tend to perform better in wetter areas than creeping root.
Lardner says a new research project is starting this year looking at the performance of forage species developed to grow in saline soils. Halo alfalfa, registered in 2013, is one of the newest varieties. It followed the salt tolerant Bridgeview alfalfa registered in 2011. And among grass species, AC Saltlander, a green wheatgrass, was registered in 2004. While it is difficult to predict weather cycles, Lardner says with wetter years followed by some dryer growing seasons, soil salinity is a concern in many areas. Farmers are interested in forage legumes and grass species that can return saline soils to productivity and help control weeds.
Lardner says over the years they have also compared alfalfa and other forage legumes in blends with various grass species. They compared PS3006 alfalfa in forage blends against cicer milkvetch and AC Glenview sainfoin blended with hybrid meadow brome grass.
And in another project it was AC Yellowhead alfalfa and AC Mountain View sainfoin blended with Russian wild rye and hybrid meadow brome grass.
Lardner says there were no runaway standout performances among the legumes — they all performed quite well, although growing conditions can be a factor. For example, in one project comparing an alfalfa/grass blend with a sainfoin/grass blend at two different growing sites, the sainfoin/ hybrid bromegrass or alfalfa/hybrid bromegrass pastures out yielded the alfalfa/Russian wild rye or sainfoin/Russian wild rye pastures in a grazing trial near Lanigan, in central Saskatchewan, under good growing conditions. At Swift Current in southern Saskatchewan, under drier conditions, the same two legume/grass blends performed about equally.
As might be expected, the forage yield and rates of gains on yearlings at the Lanigan site were between 10 to 15 per cent higher than at the Swift Current site. Moisture was the main contributing factor.
And on that point, he referred to a three-year study in southern Saskatchewan, with data still being analyzed, where they looked at including alfalfa in a pasture mix to help fill that late summer/early fall period where grasses can run out of steam due to dry growing conditions — grass growth slows down or stops and quality can decline without moisture. “It is difficult to run a pasture program anywhere on only two or three inches of moisture,” says Lardner. “But alfalfa with deeper tap roots can go down and reach the moisture and still be fairly productive. We are still analyzing the numbers on this project, but we are happy with the results from the first two years. With good performance on the alfalfa it may have a role in carrying pastures and cattle through that late summer period.”
Alfalfa grazing management tips:
- Never turn hungry livestock into a pasture containing a high proportion of bloat-causing plants.
- Fill animals with dry hay or grass pasture before beginning to graze high bloat-potential pastures.
- Avoid turning animals onto fresh, high bloat-potential pasture that is moist with dew, rain, or irrigation water. Both rate of intake and initial rate of digestion are higher from moist plants, causing more rapid initial digestion.
- Never allow animals grazing high bloat-potential pasture to get so hungry that they consume too much in one feeding. Always have sufficient feed available.
- Make paddock rotations mid-day or later to help minimize moisture and increase plant carbohydrate concentration.
- Avoid dramatic changes in forage quality when rotating from paddock to paddock by leaving adequate residue.
- Observe livestock closely the first several days and remove any “chronic-bloating” animals.
- Avoid grazing legumes before they begin to bloom. Make closer observations for bloat when many plants are at a younger growth stage.
- Manage grazing to encourage livestock to consume low- or non-bloating plants and plant parts (such as an alfalfa/grass forage blend) rather than just succulent top growth. For example, use daily strip grazing or use high stock density in multiple paddock systems rather than continuous stocking.
- Once grazing begins, don’t remove animals from pasture or make frequent, major changes in the type of pasture being grazed unless animals have greatly distended rumens. Mild bloat is common on high bloat-potential pastures. Frequent diet changes prevent rumen microbes and animals from adapting to bloat pastures.
- Be extra observant for cattle bloat when high bloat plants show a rapid flush of growth such as during cloudy, wet periods in the spring and after a plant stress event such as hail or drought.
- Delay grazing high bloat-potential plants for three to five days after freeze damage.
- Avoid grazing alfalfa stands in September as plants need adequate carbohydrate reserves for overwintering. Can graze above ground biomass after final fall killing frost.
- Graze with animals that have smaller rumen capacities, like yearlings and calves, rather than mature cows.
- Talk to your veterinarian about the advisability of using a product like Alfasure (mix with water to prevent frothy bloat).
Editor’s note: Stay tuned for part 2 with alfalfa grazing tips from cattle producers from across the country.
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