Manhattan, Kansas, USA
October 26, 2011
Winter canola can be a valuable alternative crop for many producers in Kansas. It would be even more valuable to some producers if they could utilize winter canola as a dual-purpose forage and grain crop, said Mike Stamm, K-State Research and Extension canola breeder.
Using canola as a dual-purpose crop is a new practice and more information is needed regarding the forage potential of canola and the effects of grazing on grain yields, he said.
“Simulated grazing studies of winter canola have been conducted near Manhattan by K-State agronomists over the past few growing seasons. Preliminary results show that canola makes high-quality, nutritious, and highly digestible forage. However, ranchers who graze winter canola can expect a reduction in final grain yield,” Stamm said.
In the tests, he observed varietal differences in grain yield after the forage was harvested.
“The yield of varieties with a prostrate growth habit, or those that produce rosettes that hug the ground was about the same as that of un-grazed checks,” he said.
One such variety, named Griffin, was released in 2011 by K-State Research and Extension, the first dual-purpose forage and grain variety. Seed of Griffin will be available for planting in fall 2013, Stamm said.
The availability and duration of canola forage is more weather dependent than it is for winter cereals, he says. Canola should not be grazed if the threat of too little fall growth for overwintering exists, which could be the case this year where emergence was delayed by dry weather, he said.
The amount of forage produced by winter canola is variable, said Todd White, K-State Research and Extension forage agronomist.
“Above-ground wet biomass has ranged from 2 to 10 tons per acre, and dry weights have averaged about 0.4 to 2 tons per acre,” White said.
This fall, canola will probably produce less forage than normal, Stamm added.
Ranchers report their animals develop a taste for canola after a few days of grazing it, and noticeably devour the crop before moving to different forages, Stamm said. Others have noticed cattle are not interested in the crop until after a hard freeze.
Some ranchers have seen daily gains greater than 3 pounds per day when grazing winter canola, White said.
“Preliminary grain yields show that simulated grazing of canola reduces grain yield by 50 percent in the fall, while grazing canola in the spring reduces grain yield by 70 percent,” Stamm said.
For this reason, grazing is not recommended if the objective is to produce high grain yields, he added.
“Do not graze canola in the spring unless you intend to graze it out,” he said.
K-State agronomists share management tips for grazing canola
When grazing winter canola, proper management practices can make a big difference – for the cattle and the crop, said Mike Stamm, K-State Research and Extension canola breeder and Todd White, K-State Research and Extension forage agronomist.
Stamm and White outlined points to keep in mind when grazing winter canola:
* Canola forage should not be grazed if the seed was treated with an insecticidal seed treatment. These seed treatments are systemic and can cause irritation when cattle consume the forage.
* A slightly earlier planting date is advisable to allow for maximum forage growth prior to grazing, but adjustments to seeding rates are not necessary.
* Stock the canola field when the canopy height is approximately 6 to 8 inches tall. Generally, the most forage is available upon reaching the eight-leaf stage and canola grows vigorously at this stage.
* Adjust the stocking rate so mostly new growth is consumed and remove cattle when only half of the original forage remains. Producers may use flash grazing, which means grazing the canola for a brief period of time, removing the cattle to allow re-growth, and then returning the cattle to the canola forage.
* To better utilize the crop, graze canola with younger cattle such as stockers rather than older cows. Smaller animals cause less physical damage to the canola plant.
* No more than 75 percent of the animals’ ration should be canola, with the other 25 percent consisting of a lower quality, high-fiber hay.
* Since canola is relatively low in fiber, producers should exercise caution when introducing cattle to the forage and may want to consider a bloat preventer. Cattle should be full, near a source of fiber, and closely monitored when initially placed on canola pasture.
* It is critical to monitor winter canola for nitrate content before and during grazing. High nitrate concentrations may be found in the petioles of the leaves. Thus, after cattle remove the leaves and begin feeding on other plant parts, the risk for nitrate poisoning increases. Research has also shown that nitrate content decreases significantly following a series of hard freezes.
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