Cattle will eat canola plants and canola can provide an adequate feed source. The decision to cut canola for feed should compare all costs and opportunities for seed versus feed. This article will provide details to help with that decision.
Weather events that have farmers wondering about canola as feed include late-season hail and drought. Drought reduces canola yield potential and increases the demand for alternative feed sources. Drought, especially widespread drought, can also drive up canola seed prices, which can maintain profitability for canola crops harvested for grain – even if yields are quite low.
Before making a decision to cut a canola crop for silage or hay, consider these steps:
- Calculate the return for canola harvested for grain, considering yield potential and price. A 10 bu./ac. crop could produce $200 per acre at July 2021 prices. What is the likely harvest-time price and how does that compare to hay prices?
- Talk to the grain buyer, especially if signed contracts require delivery. Review the contract commitments. A 10 bu./ac. canola crop that covers at least part of the contract will reduce the amount that needs to be replaced to fulfil an obligation.
- Talk to the crop insurance adjuster. If making an insurance claim, the adjuster should assess the crop before the farmer considers the silage or hay option.
- Check labels for all pesticides used on the crop. Some products used on canola have restrictions such as “Do not graze the treated crop or cut for hay.” Because canola is not a common feed crop, the Pest Management Regulatory Agency (Canada) and Environmental Protection Agency (U.S.) do not require feed data, so companies may not have data to support feed use after their products are applied.
- Look at the crop stage and estimate biomass. This will determine the potential feed value per acre. Canola feed value drops after late flowering and early pod stages.
- Consider loss of nutrients that occurs with removal of all above-ground biomass. This will have to be replaced with added fertilizer.
- Do cattle producers need help? Feed shortages add to the stress of drought for livestock producers. This might factor into a decision to leave canola standing or cut it for forage.
Canola feed value
Feed value tends to be higher when canola is cut at full bloom to early pod stage when plants are still green and leafy. Here are a few feed components to consider when feeding canola.
Crude protein. This can vary widely. Crude protein for canola cut at full bloom to early pod can average from 14 to 17 per cent, says Alberta beef feed consultant Barry Yaremcio. Manitoba Agriculture has a factsheet Manitoba Average Feed Values for the Beef/Bison/Sheep Producer that compares various crops, including canola. Comparison data comes from samples sent to Norwest/Bodycote Lab between 2000 and 2005. For canola silage (eight samples), crude protein ranged from 9.3 to 23.5 per cent, with an average of 14.7 per cent. Alfalfa, all cuts, had an average of 17.4 per cent. For canola green feed (14 samples), crude protein ranges from 8.2 to 16.4 with an average of 12.3. Yaremcio says canola protein drops to the 10 to 12 per cent range at full pod due to the lost leaf and flower biomass.
Total digestible nutrients (energy). Lab results from the Manitoba Agriculture factsheet show average total digestible nutrients (TDN) of 59 per cent for canola silage and 56 per cent for greenfeed. Yaremcio puts the average at 55 to 60 per cent, which is similar to a good alfalfa-grass hay, he says.
Nitrates. After a light frost or hail, cut canola as quick as you can, Yaremcio says. Nitrate accumulates after the injury and peaks three to four days after a light frost. With a killing frost, the plant is dead and nitrates do not accumulate, but nitrates in the plant at this time are locked in. Ensiling tends to reduce nitrate levels. Get a feed test before using any new or unusual feed source. (Note: Many crops will accumulate nitrates, so tests for all feed sources are recommended. NDSU has a document on nitrate poisoning.
Sulphur. One concern with canola (brassicas in general) is that it tends to accumulate sulphur. NDSU says sulphur levels of canola can range from 0.5 to 1.3 per cent on a dry-matter basis. Yaremcio says sulphur levels above 0.4 per cent will affect rumen bacteria in cattle, which can lead to serious illness. NDSU says water sources and other byproducts, such as distillers grains, can also increase sulphur intake for cattle. Get a feed test to know how to blend canola silage with other feed sources.
Oil. Mature canola seed would not be appropriate as a sole feed source. While canola oil is used to boost energy in feed rations, more than seven per cent oil in a cow diet prevents turning in the rumen. This amount of oil essentially causes an impaction or feed blockage due to loss of “traction” as it sits in the stomach. Mature canola seeds in hailed or regrown feed could contain 40 per cent oil. This would only be a concern if mature canola seed represent a significant part of the diet.
To test feed quality, borrow a feed probe (local extension offices may have them) and send the sample for feed analysis. The office with the probe will also know where to send samples. Each province has a few labs that test feed. Check with the chosen lab for their sampling and submitting procedures. Also check with a provincial livestock and feed extension specialist to discuss feed testing and the positives and negatives of using salvage canola crops in rations.
Price of canola forage
In July 2021, Barry Yaremcio said: “Hay is advertised at 8¢ to 10¢ a pound. Greenfeed and salvage cereal and canola crops are probably 1¢ to 2¢ off the hay price. So a 1,000-pound canola bale could be worth anywhere from $80 to $90 per bale.”
Manitoba Agriculture staff estimate that canola silage would be similar value to beef hay on a dry matter basis. If beef hay at 15 per cent moisture is 8¢ per pound, a canola silage bale at 50 per cent moisture would be around 4.7¢ per pound.
One way to estimate forage yield is to cut and weigh all the plants in a square foot and do that a few times throughout the field. Then multiply to get yield per acre. An acre is 43,560 square feet. This is, of course, just an estimate and mass will be lost as cut plants dry down.
The manual, Procrop Canola Growth and Development, from Australia has a section on cutting a failed crop. If total dry matter yield is 1,818 kg/ha (0.74 tonnes per acre) at late flowering, it will drop to 1,181 kg/ha (0.48 tonnes per acre) over the next six weeks. In that time, dry matter digestibility also drops from around 69 per cent to around 59 per cent.
When to cut
Quality is best when cut at full bloom to early pod stages. Quality goes down as canola matures. Australian research on feed quality of drought-affected canola says: “To maximize animal performance and minimize cost per unit of energy from baled drought-affected crops, they should be cut early, ideally around flowering.”
- More on silage. Yaremcio says to treat canola similar to barley for cutting, chopping and packing or bagging. He adds that it will probably take an extra day to dry down to 60-65 per cent moisture content – a day longer than cereal silage. A Government of Saskatchewan factsheet says: “There may be seepage and ensiling problems if brassicas are ensiled at moisture contents greater than 70 per cent.” Note that canola silage tends to have a darker colour and perhaps a less appealing smell than barley silage. While cattle are reported to adjust to canola silage easily, blending with other feed sources, especially when first introducing canola to cattle, is recommended.
- More on hay. Brassica plants like canola may take four to six days to dry down to proper moisture levels for baling, which is 16 to 18 per cent. Crimping the hay ensures faster and more uniform drying. The Government of Saskatchewan factsheet says: “If canola is cut near maturity, its feed value will be similar to that of cereal straw. Cattle do not find this type of feed palatable and it is best used as bedding unless it is processed and mixed with other hay.”
- Barry Yaremcio, Yaremcio Ag Consulting Ltd., 403-741-6032 www.beefconsultant.com
- Manitoba Agriculture staff, including Dane Froese, Shawn Cabak and Juanita Kopp
- Manitoba average feed values for the beef/bison/sheep producer, Manitoba Agriculture
- Beef cow rations and winter feeding guidelines, Saskatchewan Ministry of Agriculture. This provides sample rations using canola hay and silage.
- Brassica Crops for Hay and Silage (Canola and Mustard), Government of Saskatchewan factsheet
- Drought-stressed canola possible forage for livestock, NDSU 2021 news release
- Alternative feeds for ruminants, NDSU
- Procrop Canola Growth and Development, Australia
- Drought affected canola and wheat – feed quantity and quality decline in standing crop, Australia