Winter management must start in the fall, before cold weather. This means carefully assessing body condition on pregnant cows when calves are weaned, and developing a plan to provide sufficient nutrition to allow cows to maintain moderate-to-good condition before their next calving.

James England, University of Idaho DVM, says cows must be in good condition (preferably a body condition score 6) to handle weather, calving and rebreeding. “With adequate condition at the start of winter and good maintenance throughout, most animals winter well. But, without adequate nutrition, anything else we do is set up for failure,” he says.

Stockmen often underestimate the importance of fall nutrition and body-condition scoring. In fact, Ron Skinner, a Hall, MT, DVM and seedstock producer, says about 70% of open cows in Montana each year are the result of inadequate fall nutrition.

An adequate, balanced diet may merely mean adding a trace-mineral supplement to native pasture, some good hay, a protein supplement if grass becomes too dry, or hay if the grass becomes depleted or snowed under. If a cow is deficient in protein or phosphorus through fall and winter, she won’t rebreed on time after calving. Plus, thin cows are unable to handle the stress of bad weather and lose more weight. And, it takes more feed to put weight back on a cow during cold weather.

If you manage pastures properly – without overgrazing or running out of grass – forage-efficient cows won’t lose much weight during fall or winter grazing; they generally gain weight after weaning calves and go into winter with fat reserves.

Many factors influence a winter-feeding program. These include climate and grass growth; whether pastures snow under and can’t be grazed; the available forage your climate or operational design (irrigated vs. nonirrigated pastures, forage varieties, crop aftermath, etc.) allows; and the type of cattle. It’s most profitable to match the cattle to your feed sources rather than try to feed cattle not fit to the environment.

To help cattle maintain health and body condition during winter, vaccinations should be up to date, parasite populations assessed, and cattle dewormed and deloused, if necessary.

“If lice are a winter problem, it’s best to delouse cattle in late fall/early winter, before lice start to increase in numbers,” says Jack Campbell, University of Nebraska professor emeritus. “Lice increase their reproductive rate in cold weather, so you get more generations in a shorter time span.” A good kill in early winter – before lice affect cattle performance – will generally keep cattle free of these parasites until spring.

Adjust feed for cold weather

How much hay or supplement a cow needs depends on weather conditions, cow age and body condition, available pasture or crop residue, and reproductive stage of the cow. Some herds do well through fall and winter on good native pasture with just a salt/mineral supplement, especially if cows aren’t nursing calves. But, if snow covers the grass deeply or weather gets quite cold, they may need hay.

In cold or stormy weather, cattle need more energy to maintain body heat. This can be adequately supplied by forages, since fermentation breakdown of roughage in the rumen produces heat. If cattle aren’t fed additional energy, they rob body fat to keep warm, and lose weight.

During extremely cold or windy weather, cows should be given all the hay they’ll clean up, or a protein supplement on dry pastures to encourage them to eat more. As long as protein is adequate, cows can process/ferment sufficient roughage to provide energy and body heat. Access to good windbreaks during severe weather is important to reduce cold cows’ stress and energy requirements, as well.

“Assuming cows have adequate energy from forage, the next important thing is mineral supplementation, which is critical for digestion of forage,” says Dick Fredrickson, DVM/nutritionist for Simplot, Grandview, ID.

Salt should always be provided, since this is the mineral most lacking in forages. Some geographic locations also are deficient in copper, selenium or zinc, so know the mineral content of your forages and provide supplements accordingly.

“The trace-mineral status of the cow affects all aspects of production and reproduction, as well as the future well-being of her calf,” England says.

Drought-stressed grass may be short on protein and phosphorus. As a general rule, range grasses hold their feed values better through winter than tame or irrigated pastures, or crop residues. These lose nutrient value once they dry up or freeze, and cattle generally need supplemental feed (hay, silage, grain or a protein supplement and mineral mix).

If pasture is depleted or snowed under and you’re feeding hay, managing cattle in groups is best. “You don’t want to waste hay by feeding better-quality feed than a group needs,” says Shannon Williams,

Lemhi County Extension, Salmon, ID. “Cows in early or mid-gestation don’t need your best hay; save it for later or feed it to heifers and two-year olds.” Of course, the only way to truly know the nutritional value of hay is a lab analysis, Williams adds.

Weaned calves need the highest-quality feed; next would be pregnant heifers and two-year-olds that just weaned off calves. This is a critical time for this latter group as these females are still growing and pregnant, and nursing calves may have pulled down their condition. Mature, dry cows can get by on lesser-quality forage, be it pasture or hay, until late gestation.

“Adequate protein is crucial during the last 60 days of pregnancy for development of the unborn calf, and for colostrum formulation,” Fredrickson says. “If scours is a problem in the herd, timely vaccination for scours needs to be administered at this time also,” he says.

Having cattle on pasture through winter is healthiest for both cows and their calves next spring. If you must feed hay, spread it out in large pastures and change feeding areas daily, rather than congregate cattle in small feeding areas, Skinner says.

Low-cost alternatives

Some stockmen reduce winter feed costs and labor by relying less on harvested forage. This strategy might include stockpiling pastures or windrowing forage for winter use, or bale grazing (leaving big bales in fields for cattle to eat).
“Grazing cows on stockpiled or windrowed forages as long as possible and then keeping harvested-forage feeding to a minimum is essential to a low-cost wintering program and profitable cow-calf operation,” says Jim Gerrish, a management-intensive-grazing expert, May, ID.

“Closely monitor cow body condition and use strategic supplementation to stretch out stockpiled pastures. Even with the relatively high cost of adding protein to the diet, using a supplement to enhance stockpiled pastures or rangeland is almost always a lower-cost option than full feeding hay,” he says.

With stockpiled or windrowed forage, cattle will trample/graze through relatively deep snow to get at it, unless snow is thickly crusted. And, utilizing electric fencing to move cattle gradually across a field can minimize waste. Gerrish says these methods can lengthen the grazing season but be sure to monitor cattle condition and ensure cattle have access to water and windbreaks.

The same is true with bale grazing. A calculated number of bales to provide a certain volume of hay/cow for a certain number of days can be placed in rows, with twines removed before wet, freezing weather makes that task difficult. Electric fence allows cattle access, using the next row as a handy place to insert “posts” (into the bale) rather drive them into frozen ground.

Some ranchers bale-graze young stock, too, letting weanlings/yearlings into each new section first, with dry cows following to clean up; both groups are moved when cows finish their section. This method spreads manure over fields uniformly.

But, probably the most important factor affecting winter cow management is matching cattle to the environment and your management style. Cows that need extra feed to maintain body condition and remain in the herd under “normal” conditions aren’t the kind of cattle you want. If pastures are managed properly, forage-efficient cows won’t lose weight during fall or winter grazing.

It’s most profitable to match the cattle to your feed sources rather than try to create a feeding program to fit cattle that won’t do well on their own in your environment.

Heather Smith Thomas is a Salmon, ID, rancher and a freelance writer and book author on cow-calf management.