Producers facing feed shortages can feed straw and chaff to weaned animals, mid pregnancy cows and mature bulls
ROCKY MOUNTAIN HOUSE, Alta. — Straw might not be a cow’s first meal choice, but it might be all that is on offer this winter.
Cows need to be well fed to make sure they reproduce next year.
“With feed shortages using straw and grain rations, what will happen next year if you don’t have these cows going through winter in good shape?” said beef specialist Barry Yaremcio of Alberta Agriculture.
Body condition needs to be monitored to ensure the cow is getting enough to eat, he said at a recent Grey Wooded Forage Association feed workshop.
Body condition score indicates how much fat an animal is carrying at different points of its life.
A cow in good condition can produce enough milk to wean a larger calf.
Cows entering the winter in good condition need extra fat for insulation against the cold. Fat is also a reserve when feed supplies are short.
“If your cow is in good shape, the rib and pin bones should not be sharp to the touch,” he said at a Grey Wooded Forage Association feed workshop.
If the cow is thin, the ribs are easy to feel and the indentations between the ribs are noticeable. There will be no indentations between the ribs in fat cows.
A change of one body condition score is a loss or gain of 200 pounds.
Feed also needs to be matched to the animal’s stage in life.
He suggested feeding straw, grain or chaff piles to weaned animals, mid pregnancy cows or mature bulls.
“Save your high quality forages for after calving because that is when your nutrient requirements are the highest,” he said.
A pregnant or lactating cow needs an extra 25 percent nutrition.
Straw is high in neutral detergent fibre, which is the bulkiness of the feed. NDF intake should be limited to 1.2 percent of body weight.
A 1,600 to 1,800 pound cow can take up 60 percent while a 1,200 lb. cow can take 40 to 50 percent NDF in the diet.
Straw does not work for lactating cows or young calf rations because it is too bulky and too slow to digest.
Adding liquid molasses to a straw bale does not encourage cattle to eat more. They can only take in so much straw because of the high fibre content. Molasses may help with taste and result in less waste but they cannot increase dry matter intake per day.
Cereal straw is a good filler but a minimum of seven percent protein supplement is needed to maintain rumen function.
“If you get below that, you will get impaction problems. They will get skinny because they are full of fibre and it is not being digested,” he said.
Cereal straws are often short of calcium so Yaremcio recommends adding four ounces of limestone and magnesium oxide per cow per day.
Pea straw has six to seven percent protein and the energy content is equal or slightly less than oat straw.
There may be some peas left over from harvest so feed value is improved. It takes a few days for animals to adapt to pea straw because it has a wax coating and a different taste.
Flax straw is not recommended. It has low digestibility and if there is some green fibre left it could include prussic acid, or hydrogen cyanide. It could kill animals instantly.
Canola straw carries about five to seven percent protein and has the same energy content as cereal straw. However, it has a hollow stem so producers should never put it through a bale processor because it will turn to dust.
Other feed choices also have challenges.
A first-year seeded hay crop is generally good quality if cut when it is immature. It may contain a lot of weeds.
Kochia in the mix may have a high level of oxalates that can inhibit calcium absorption.
Weeds may contain alkaloids or nitrates. Ergot alkaloids are most common and can cause photosensitivity and chapped skin around the eyes, anus and udder.
Slough hay quality depends on crop maturity. It is better than cereal straw but not as good as tame hay. It may also contain poisonous plants or invasive weeds. Cows may pass the seeds and unwanted plants show up everywhere.
Hail-damaged crops are variable in quality so feed testing is important.
If the crop was heavily fertilized with nitrogen there can be nitrate problems.
As well, crops should be cut immediately after a storm or producers should wait two weeks to curb nitrate toxicity. Damaged crops tend to have low sugar content.
Regrowth of damaged crops can be turned into a quality silage with an inclusion rate of 15 to 100 percent of the ration depending on quality.
Grazing corn offers variable nutrition.
About 50 percent of the yield comes from the cob but this year formation was below average.
The entire corn plant has about nine percent protein. It is good for dry cows in mid to late pregnancy. They will need a continual supply of extra protein for proper rumen function.
The cows should have a maximum of three days in a paddock to encourage them to clean up cobs, leaves and stalks.
Calcium and manganese are deficient in this crop so a feedlot-style mineral program works well.
Corn is not suitable for lactating cows and growing calves without grain and protein supplementation.
Cows will dig through the snow to find chaff piles. Quality depends on grain and weed seeds in the pile.
Weed seeds may contain 15 to 16 percent protein. If the cows break the seeds by chewing they will be digested well.
This is a low protein product and is good for dry cows or those in mid pregnancy. Chaff is low in calcium and magnesium but high in fibre. Supplemental protein and energy may be needed.
This year’s barley harvest is coming at about 34 to 51 lb. per bushel.
Lighter barley is less desirable and processing to crack the seeds consistently can be a problem.
“For every pound of bushel weight drop below 42 lb., the efficiencies drop five percent,” he said.
Dried distillers grains, malt sprouts or oat hulls are good products but supply and quality can be inconsistent.
Protein and energy can be consistent in these products but ergot may be present and cows may reject it.
DDGs with solubles are a good source of protein but can be high in sulfur and phosphorous. This product can make up 15 to 40 percent of the ration. Start by feeding small amounts and gradually increase in the ration. Watch for sloppy manure or unusual behaviour where cattle do not want to eat it.
A normal cow pie versus one that is piled up like a pyramid means the fibre was not digested properly and there is a protein deficiency.
Protein is needed for growth and proper digestion. Rumen microbes need protein as a food source so they can digest fibre. A protein deficiency can result in a loss of body condition.