“With dry conditions in the northern and southern parts of the province, late seeding and hail storms in others, some canola crops could be candidates for salvaging and used for cattle feed,” explains Barry Yaremcio, beef and forage specialist at the Alberta Ag-Info Centre.
“If the flowers are blasted from the heat, or are in full bloom now, or have been damaged by hail, it will be difficult to realize a high yield. It will be difficult to have a late seeded crop mature sufficiently to produce mature - black - seed prior to a fall frost.”
He says that canola plants in full bloom to early pod stage can have the same nutritional value as a good quality first cut mixed alfalfa-grass hay.
“Cattle will readily eat canola greenfeed or silage. If the animals have not previously experienced this feed type, it may take them 2 or 3 days to readily consume it. Depending on quality, canola greenfeed or silage could possibly make up 100% of the daily ration. Hail-damaged canola is more difficult to evaluate, and a feed test result is needed before any recommendations can be made.”
He notes that there are two additional concerns when feeding canola silage or greenfeed compared to using a cereal crop as cattle feed
Nitrate and sulphur – If the canola has been fertilized to produce a high yielding crop, Yaremcio says that nitrate and sulphur content could be a concern.
“Nitrate is more of a concern with dry conditions because the crop did not develop sufficiently to use all the applied fertilizer. High sulphur content - above 0.4% in the complete ration - can cause polio. A representative sample needs to be sent in for analysis - including nitrate and sulphur - to establish feed quality.”
Oil content – Canola seed can contain up to 42% oil by weight when fully mature, and oil is starting to develop in the immature seed two weeks after full flower. As the plant matures, the oil content continually increases with most of the oil developed between 35 and 55 days after full flower.
“Rumen function is impaired when total fat or oil content in the ration exceeds 7%,” he explains. “Rumen contents do not ‘turn’ properly, and that causes a reduction in feed intake, possibly even a bloat situation. A test for fat or oil content should be requested when testing the feed.”
Plants drop leaves as they mature, and those leaves contain a large percentage of protein and energy contained in the plant.
Yaremcio says that bacteria involved with the ensiling process obtain energy from soluble sugars obtained from the leaves.
“If the leaves have dropped, less energy is available and the ensiling process could take one to two weeks longer compared to a crop that supplies adequate sugars.”
He adds that producers should consider working with various industry professionals including private consultants, feed company nutritionists or government specialists to develop a feeding program for the different types of animals that can utilize canola greenfeed or silage.
Connect with the Alberta Ag-Info Centre:
Hours: 8 am to 5 pm (open Monday to Friday, closed statutory holidays)
Toll free: 310-FARM (3276)