Wintering Calves with Their Mothers

Wintering Calves with Their Mothers

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Some people think wintering calves with their mothers won’t grow well on forage, but they actually do quite well.

Traditionally, cow-calf producers calve in the spring and wean in the fall. This works for people who calve in February and March (or even April) or seed-stock producers who calve in January (to have bull calves old enough to sell as yearlings in a spring bull sale). In recent years, however, more cattlemen are trying to calve in sync with nature on green grass — when cow/calf pairs don’t need hay, and the weather is better for newborns, saving on hay and labor.  

Calving in May and June (or even July) works great, but those calves may be too young for weaning in October or November, so some people are leaving calves with the cows into winter, sometimes weaning as late as March.   

This works well if the pairs can graze through winter on crop aftermath, cornstalks, stockpiled pastures, windrowed forage, or bale grazing (eating bales left in the field for winter use or bales placed on a pasture that needs more litter/fertilizer to improve soil health and fertility). If calves can be out on pasture with their mothers — even if the herd is being fed hay — rather than confined, they do better and stay healthier.   

Some people think calves won’t grow well in cold weather, wintered with their mothers on forage, but they actually do quite well. If the cows won’t be calving again until May or later, they have adequate time to recover from lactation even if calves are weaned as late as March. At weaning, the calves can be fed good forage, and the cows can go back to the winter feed program (cornstalks, bale grazing, windrows, or whatever they were grazing before) until green grass. Calves experience less stress when weaning at about 10 months; they don’t miss their mothers as much, and the cows have already weaned some.   

Even if the cows have lost a little weight by the time the calves are weaned, they fatten up again before they calve. Cows only need about 45 to 60 days of “dry time” before calving again.  

Weaning summer-born calves at a young age, in late fall/winter weather, often results in more sickness, primarily if the calves are confined in a corral. It’s better to leave them out on pasture with the cows. Calves learn from their mothers how to graze through snow, seek out forage, find windbreaks, etc. and the heifer calves become better cows. Calving in May/June means selling light calves if you are marketing calves in October/November. But if you leave them on the cows and run them on grass the next year to sell in August or September, they are a good weight, bring a reasonable price, and you don’t have much feed investment.  

Wintering pairs can save on feed and labor. This makes winter chores easier — with just one herd to deal with instead of a herd of cows and a pen of weaned calves. In a grass-based system, working with Nature, keeping calves on their mothers, is better than grain-feeding to develop their rumens, so they become efficient on grass. If the pasture, cornstalks, or bale grazing is poor quality forage for calves, a creep area can be provided. It’s not for feeding grain; it’s a place they can get in, and the cows can’t, and the calves can have higher-quality hay. The cows can be on a cheap straw-based or poor-quality hay ration and protein supplement, but calves do better with higher-quality forage.   

During severe winter weather, windbreak and bedding in the creep area will be beneficial if there’s no brush to provide adequate shelter. One rancher uses his main corral as a creep area; the cattle come into the corral for water and protein pellets, and the calves can go into another pen through a creep gate. There are hay bales and bedding for the calves, and they can come and go as they wish. When it’s time to wean, it’s just a matter of closing the gate when they are all in that creep corral eating hay. This is stress-free weaning; the calves are in a familiar place with familiar feed and haven’t been stressed by being sorted. The cows are nearby, through the fence.  

Late Weaning is Natural

By 9 or 10 months, calves don’t need milk anymore, and the cows are not producing much. By that age, the calves are also very independent and ready to wean. Mother Nature programmed cattle, like bison, to spend their first winter with their mothers. In nature, cows suckle calves through winter, then kick off the big calf the following spring before giving birth to the next calf. The older calf tags along, stays with mama and the new baby for awhile, and is never stressed.  

Even with good feed for an early-weaned calf, we can’t do as much for them as their mother can. She may lose weight, lactating through winter, but if she isn’t calving again until May or June, it doesn’t matter if she loses 200 pounds. If she has 45 days of green grass before she calves again, she will put on enough body condition to have a healthy calf and breed back within 80 days after calving.  

Whether a cow is on stockpiled grass pasture or hay during winter, it contains all the necessary micronutrients she needs but very little actual energy. However, it doesn’t take much energy for a cow to produce butterfat; all she needs is adequate digestible fiber. Her rumen microbes create energy during the breakdown of fiber. In winter, her milk has more fat and less protein. She is giving less volume than she would on green grass, but the milk quality is very high.   

The evolutionary function of milk produced by mammals is to supplement their young until those babies can consume adult food, so why wean calves before when they can live off forage? There’s no reason to wean early (unless you are in severe drought and cows don’t have adequate forage) if it means you have to provide calves with more energy and protein to keep them growing. That’s what milk does for them.  

It is easier to supplement calves through winter via their mother’s milk than to supplement them with grain. The natural lactation curve matches the needs of a growing calf; the closer the calf gets to adulthood (and the closer the cow gets to the next calf being born), the less milk is produced.   

Before domestication or selective breeding, cows gave a moderate amount of milk and fed their calves through winter without problems. By selecting for heavier weaning weights in beef cattle, we indirectly selected for heavier-milking cows. They become too thin on poor pasture if lactation continues into winter. On many ranches, it is better to have efficient cows that keep some nutrients for themselves without getting too thin during lactation. Weaning time can be delayed until spring, but keeping calves on the cows may not be a good option for a heavy milking herd since this puts more nutritional stress on the cows. It all comes down to a management decision to have that kind of cow. A heavy-milking cow is not as efficient in many ways as a more moderate-milking cow.  

But if cows are average in milk production and winter feed is adequate (grass or hay), it may be more cost-effective to leave calves on the cows longer or even leave them together through winter if the calves were born in summer rather than early spring. 

HEATHER SMITH THOMAS ranches with her husband near Salmon, Idaho, raising cattle and a few horses. She has a B.A. in English and history. She has raised and trained horses for 50 years and has been writing freelance articles and books for nearly that long, publishing 20 books and more than 9,000 articles for horse and livestock publications. Find Heather online at    

Originally published in the January/February 2023 issue of Countryside and Small Stock Journal and regularly vetted for accuracy.

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