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Big on forage brassicas

Versatility and volume outweigh any risks involved

Ben Stuart

Seeing is believing for Graeme Finn, who says New Zealanders are on to a good thing with forage brassicas for winter grazing in their grass-based systems that yield massive tons of high-quality beef, lamb and milk from the country’s tiny land base. A trip there four years ago convinced him that if forage brassicas are suited to New Zealand’s coolest season, they should be great for summer grazing in Western Canada.

They haven’t disappointed. The number of acres sown to forage brassicas and forage-brassica blends sold by Union Forage jumped from a relatively few acres in 2014, to 22,000 acres last year.

Finn and a business partner formed Union Forage, headquartered at Lethbridge, Alta., in 2014, when Finn acquired the Canadian distribution rights for certified forage brassica cultivars developed by PGG Wrightson Seeds of New Zealand. Union Forage specializes in marketing select annual and perennial grazing forages and works with the U.S. subsidiary, PGG Seed, to offer the most suitable forage brassicas and blends for Western Canada.

Forage brassicas are crosses of forage-type kales, turnips, Asian leaf vegetables, cabbage and radish that have been developed by PGG Wrightson Seeds for palatability, high biomass production and profitability with animal performance as the ultimate measure of merit.

Two kale-turnip offerings available through Union Forage are Winfred and Goliath. They can be grazed 45 to 60 days after planting. Hunter, a turnip-Asian leaf cross, and Graza, a forage radish, are ready to graze in 30 to 45 days. Corrine Ethiopian cabbage can be grazed 40 days after planting and also has biofumigation properties to help suppress soil-borne pests and diseases.

Forage brassicas are generally planted in a mix so that they make up no more than 50 per cent of forage intake to be on the safe side for animal health. The mix can be as simple as a couple of pounds of brassica seed with one or two of your trusted cereals, such as oats, barley, triticale or fall rye. This is an effective combination because the high digestibility and crude protein of the forage brassica complements the higher fibre and starch content of the cereals.

Finn got his start with forage brassicas this way on the family ranch near Madden, Alta., along the foothills north of Calgary. The idea was to convince the cows to do a better job of cleaning up the oat-barley swaths to save him the time and expense having to do so much harrowing before spring planting. It worked like a charm and significantly improved the overall crude protein level in the swaths. The mixed swaths tested 16 per cent protein at the end of January, whereas the oat-barley swaths tested 9.6 per cent.

In 2014, he bumped it up with 180 acres sown to the forage brassica-oat-barley mix that carried 210 cows from late October through May. It was excessively wet that year and approximately 50 acres couldn’t be worked until August. The late-sown mix of Winfred and Italian ryegrass provided 30 days of fall grazing before having to start on the swaths. The cost of the seed was $12 per acre and the total seeding cost was $45 per acre.

Diverse mixes, sometimes called crop cocktails, might include as many as 20 annual warm- and cool-season grasses and legumes.

Union Forage’s Ultimate Annual Blend includes 30 per cent hairy vetch (annual legume), 25 per cent Italian ryegrass (cool-season grass), 15 per cent sorghum (warm-season grass, some producers prefer millet or some of each), 10 per cent crimson clover (annual legume), 10 per cent Winfred, five per cent Hunter and five per cent Graza. The mix sells for $6 a pound and is sown at seven to 10 pounds per acre along with 30 pounds per acre of one or more cereals.

He suggests adding forage peas at 10 pounds per acre.

“The crops don’t have to be complicated. Go with what’s available, cheap and suits your needs, environment and cattle the best,” Finn advises.

Chalking up the advantages of forage brassicas so far, he’d say rapid growth for multiple grazings or emergency use, great nutritional value and palatability, drought and frost tolerance, lots of biomass to capture free energy (sunlight), improved soil tilth because of the differing root systems digging and then rotting underground, and improved moisture retention because of the big brassica roots breaking up the soil and the heavy foliage reducing evaporation.

“The advantages outweigh the disadvantages, but you really have to watch the disadvantages, especially in a year like 2015. We had a lot of rapid growth and nutrient uptake and nitrogen was an issue,” Finn says.

Excessive nitrates in feed, usually caused by an adverse weather event, may lead to nitrate poisoning in cattle.

A brassica-cereal swath.
A brassica-cereal swath. photo: Supplied

Bloat has been a bit of an issue on fields sown to diverse mixes that included forage brassicas and annual legumes. It’s not known whether the brassicas, legumes, or the combination of the two was the problem.

He has been advised to watch for sulphur toxicity, particularly when both the feed and water source are high in sulphur, but hasn’t seen it himself nor heard of others having this trouble.

“These are problems we want you to be aware of because they can be managed with good grazing management,” Finn says.

He had a quick introduction to flea beetles last spring when he saw the damage on forage brassica crops in southern Alberta and to some extent in the Calgary area. This pest can ravage a brassica crop of any kind early in the growing season when the plants are small and environmental conditions are in their favour.

This year, Union Forage will be treating all of its brassica seed with a pesticide to control flea beetles. The company also offers free nitrate testing.

For more information visit or, or call Finn at 403-312-2240.

High-producing crop rotation for grazing

The first 55-acre parcel of a 110-acre field, planted in early May to a mix of two forage brassicas, Italian ryegrass and oats, was floated on and harrow packed into the soil. All would have been well had Mother Nature co-operated, but persistent dry conditions favoured weed growth. Holding out hope, he trimmed the weeds with the haybine to set them back and prevent seed set. He was more than rewarded for his patience when rains came in late June. The brassica mix sprung to life with unbelievable growth and the cattle grazed the weeds right out of it.

Germination was much better on the second half of the field sown with the air drill during the last days of May to a mix of two brassicas, grazing radish, hairy vetch, crimson clover, sorghum grass, cow peas, Italian ryegrass, with some of his own barley, wheat and oats.

The 110 acres coupled with an adjoining 40-acre field of grass gave 90 days of grazing for 160 big 800-weight yearlings going onto pasture. With controlled access and four- or five-day moves, the yearlings rotated through the crop three times and four times in some areas.

“It was a monster crop. If it had been cut for silage, it would have been a 10-ton crop and that’s without any added fertilizer,” Lainge says.

This year, he will increase the percentage of vetch in the mix because he likes its phenomenal growth and feed value. He’ll cut back on the cereals and maybe a bit on the sorghum because it lagged in performance. He is a bit leery about taking it out altogether because you never know what this year will bring — it might be just the year for sorghum and not for another species.

“I think I’ll leave the mix alone for the most part to get a better feel for it under different growing conditions. The seed cost isn’t outrageous so I don’t want to take out something and then wish I had left it in,” he says.

The brassica mix for summer grazing will be on one of the 55-acre parcels and on another 70 acres where corn was grown last year. The other 55-acre field that was forage brassica mix last year will be sown to a mix of barley, oats, wheat, Italian ryegrass, peas and vetch for silage and the regrowth might be grazed or left as is for a protective cover. This mix will give him the option of doing some weed control with herbicide if needed.

Learning the timing and extent of weed control necessary in brassica-mix crops is really the only challenge he sees. Brassica mixes can be sown on fields treated with a pre-seeding burn-off with glyphosate, but, as with canola (also a brassica), they are sensitive to carry-over residues of some herbicides.

Soil health is another aspect of interest. He was able to build up the land with cows and corn and hopes to speed that up across more acres with the brassica-mix rotation and by leaving more soil armour (residue) in place for soil building.

Lainge started into forage brassicas fully understanding the risks backed by many years of experience growing canola, cereal and pulse crops as well as cereals and corn for grazing. Knowing Finn and seeing the success Pine Haven Colony was having with the brassica mixes were also deciding factors. Besides, even if none of the brassicas grew, he knew he’d still have something.

Opportunity options

He likes what he has seen of brassica mixes over three years growing them on the home ranch near Hardisty, Alta., and the yearling operation near Stockholm, Sask.

“Most of the perennial forage growth comes in two to three months, so the reason for trying forage brassicas at first was to try to extend grazing into the autumn season and get the weight gains up so that the calves wouldn’t be going into the feedlot when it’s the prime time to put on weight in a pasture-based system. The days are cooler and it’s not usually wet and damp, so all of the elements work for the cattle from September through November. Instead of 120 days grazing, I want 180 to 200 days,” Stuart says.

Last year, brassica mixes were spring seeded on 300 acres at the Stockholm place and 1,500 acres at Hardisty, where another 1,000 acres were autumn seeded. The crops were used for summer, autumn and winter grazing, with some taken as silage and the regrowth grazed in autumn.

As of mid-December, the herd was just starting to swath graze crop that was predominantly brassicas. By the end of the month, the grazing days worked out to 130 to 150 cow-calf days per acre, costing roughly 85 cents to $1 per pair per day.

Productivity from rotational grazing yearlings on the brassica mix last summer worked out to 300 pounds of gain per acre and the older stock were grazing the last rotation in January.

Forage brassicas are a standout in his mind because they don’t lose their nutritional quality as summer turns into autumn and winter. This is because they are biennials and don’t rush to maturity to produce seed the first year, even though they won’t survive through Canadian winters. This offers lots of options because the timing for seeding and cutting doesn’t have to be as specific as for cereals for summer grazing, silage or swath grazing, he explains.

In his experience, the earlier the mixes are seeded, the higher the growth potential. Early seeding captures spring rains to make the most of the short growing season and the forage brassicas’ ability to grow later into autumn enhances yield.

Crop cut at the traditional time in September for swath grazing later on dried out a lot and wouldn’t have lost quality had it been left standing, so now he aims for October. Seeing how the brassicas were still growing in November after a couple of light frosts and standing up well under a light snow cover in December got him wondering if winter grazing the standing crop could be an option, so he is trying some this winter to find out.

“Growing forage brassicas puts me in a position to take advantage of opportunities. If I can get away without swathing, that will be another way to save costs. Four out of five years we should be able to utilize the crop as we want and on that one year when we can’t, we wouldn’t lose that much because we could graze it in spring or leave the residue for nutrients for the next crop.”

Another significant cost-cutting measure was mounding the silage in the field where it was cut and then setting up electric tape to control the amount eaten in conjunction with swath grazing and bale grazing to spread the cattle and cycle nutrients across the field. The cows and calves graze together until weaning around the end of March and the yearlings winter separately in a similar system. Altogether, when we talked, it looked like this could be his first tractor-free winter pasturing 3,500 head in all.

The biennial nature of forage brassicas also gives them an advantage in dry spells because they will go dormant for as long as 30 days and bounce back to life when the rains come. Last spring was the driest Stuart has seen in the Hardisty area and the brassica mix sown with his trusted standbys of oats, peas and triticale didn’t look like much at all for the first month. When the rains came near the end of June, the crops took off with tremendous growth and kept on growing as the area headed into winter with the most moisture he has seen. The Italian ryegrass in a mix with brassicas was the only species that didn’t fare so well through the weather stresses.

He is looking forward to sowing a similar number of acres this year and trying a few new mixes and varieties.

As he gains experience managing above-ground growth to optimize forage and beef production, he wonders what’s really happening below ground and if some practices currently believed to be beneficial could actually be degrading the soil in some way.

“We need parameters and better indicators and ways to measure what’s happening below the ground,” he says. “Scientists have ways to measure plant-available nutrients and I hope to work with them to get data on our places. For now, we do the best we can for what makes sense for our environment and our system.”

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