Help cows kick the cold with proper nutrition

The heat of summer can be hard on your cow herd, but cold temperatures, wet conditions and blustery winds present a different set of challenges. Cold cows use more energy to keep warm. Proper dry cow management is critical to calf development and next year’s revenue.

The temperature at which a mature cow responds negatively to cold stress is referred to as the lower critical temperature (LCT). Of course, the number on the thermometer isn’t the only factor. Housing type and environment play a huge role, as do coat type and wind. As a rough guide, in still air, a cow with a fall coat has an LCT of about 45 degrees, and a cow with a thick, winter coat has a LCT of about 32.

Wind exposure will change LCTs dramatically. For instance, a sustained wind speed of about 10 mph can change a 32-degree winter day from one in which the cow is mostly OK to one that feels, to her, like an uncomfortable 18 degrees.

At cold stress temperatures, some physiological changes take place. Unsurprisingly, dry matter intake (DMI) improves. Animals will attempt to eat more energy, increasing DMI by 5% to 10%. This is a response to a cow’s maintenance energy requirements increasing by 10% or more to maintain body temperature. The worse the wind chill, the more energy the cow expends. During cold weather, try to avoid running out of feed. You will almost certainly need to increase dry matter intakes.

Clean, dry cows do better in cold weather. Keep the bedding clean and dry as well. If it has been cold, and the herd is holding production, the animals may be “paying for it” in body condition scores, milk fat or milk protein content. If any of those are reduced, the herd needs more energy. Bypass fat or extra grain can achieve this.

Ensure that dry matter intake is high, and provide feed additives that support immunity. If you’re not using an MFA feed with Rumensin and Shield Technology, consider adding these to the nutritional program. Another good feed additive is yeast culture, which is in Shield. When feed digestibility, intake and availability may be variable, yeast culture helps keep the rumen stable.

Water intake declines with cold weather, but proper consumption is crucial. Monitor for frozen troughs, and make sure that water refresh rates are acceptable. Cows will drink more warm water.

Body condition score is helpful, but it has a built-in delay. By the time you notice a decline in body condition, the cow already has problems. In contrast, manure score gives information about the current state of the cow’s nutrition. For example, if manure is loose or liquid, the animal is likely getting excess protein. If manure is hard and dry, it is more likely insufficient protein. Manure scoring helps determine when you should increase supplementation.

You can somewhat evaluate forage quality by looking at a pasture, but that is not enough. Forage sampling is necessary to assess the nutritional resources available to your herd. Cows graze selectively, so be sure to get a representative sample of what your cows are consuming. The results can show the nutritional needs cows are able to meet on forage alone and what other requirements must be met.


“The worse the wind chill, the more energy the cow expends.”

Provide supplements according to the limiting nutrient. For a spring-calving cow, the limiting nutrient will likely be energy or protein until about two months before calving. In the last two months of gestation, focus on energy. Cows should get at least 2 pounds of crude protein a day. Adjust supplements to meet the changing requirements. This type of management requires monitoring and planning but prevents overfeeding expensive nutrients and depriving the cow of others.

You should also price supplements by the amount of limiting nutrient. This is especially true for convenience supplements such as tubs or range cubes. A product that is less expensive per ton is not necessarily less expensive to feed.

Attention to a dry cow’s nutritional requirements can keep her in the condition needed to successfully calve. Calves born to nutritionally sound dams perform better. Cows that calve in good condition are better equipped to care for their calves and are more likely to rebreed and return to estrus sooner.

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