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.

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.