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Time to turn up the heat on your cold weather calf care

Susan Day Published on 07 October 2009
Pulling on a sweatshirt or grabbing a jacket before you head out to the barn should be a reminder that winter is on its way. It should also be a reminder that as you make adjustments for the approaching cold weather, your calves will need preparation as well.

To prepare calves for cold weather, it’s important to understand how they react to it. Calves are generally comfortable between 50°F and 75°F, known as their thermo-neutral zone.

Within this temperature range, calves experience the least amount of heat or cold stress and don’t require additional energy to maintain their body temperature. Below 50°F, calves start using more of their energy to maintain their body temperature, limiting their ability to build energy reserves or grow.



Calves fed a full potential diet have the energy needed to resist cold stress while continuing to grow. Calves fed just at or below maintenance requirements are more likely to become sick with their first exposure to disease and will fall even more behind on weight gain and overall structural growth.

Encouraging calves to consume enough milk or milk replacer and feed to meet their maintenance needs while growing into healthy heifers is vital. A calf’s energy requirement for maintenance increases 1 percent for every degree the temperature drops below the calf’s thermo-neutral zone.

This means that at an average daily temperature of 25 degrees, a calf will need 25 percent more energy just for maintenance, let alone growth. In order to provide your calves with adequate nutrients when temperatures fall below freezing, incorporate an extra feeding of a full potential (28:20) milk replacer with soluble fiber technology in the middle of the day.

This additional feeding not only increases calves’ total nutrient and fluid intake by 25 percent, but the milk replacer helps warm them. Since they are already up drinking milk replacer, they are also more likely to consume calf starter.

Calf starter makes up 75 percent of their energy and protein in the first 12 weeks of life. Feeding calf starter with 20-22 percent protein is the best way to provide calves with energy and protein they need to regulate their body temperature.


To stimulate calf starter consumption in young calves, remember “less is more.” Within the first two to three days of birth, start offering them small handfuls of fresh, high-quality and highly palatable calf starter, so as not to overwhelm them or waste calf starter.

Water consumption
Since milk replacer flows directly to a calf’s abomasum, clean, fresh free-choice water must be offered in order to improve feed intake and support rumen development. Rumen development in young calves generally occurs during the first 4 to 8 weeks of life.

Calf starter intake, working in tandem with water, helps them establish the rumen bacteria necessary to absorb and transform nutrients into the protein and energy calves need to grow. A well-developed, functioning rumen also generates heat, which helps keep calves warm.

To ensure that your calves are drinking enough, provide warm water with morning and afternoon feedings and consider incorporating a noon watering as well. Make sure to remove any slushy water or ice at least twice a day from buckets.

To prepare newborn calves for the winter weather, it’s critical to house them in an area that is protected from drafts and moisture, and to make sure they are completely dry before exposing them to cold weather. Some hutches are equipped with warmers that newborn calves can be placed into to warm up.

Otherwise, calves can be kept in the warm barn or shop until dry. Heat lamps may also be used, but only if applied properly to avoid direct contact with the calf or flammable objects. Regular supervision is a must when using heat lamps.


Healthy calves can handle colder temperatures as long as they are kept dry and protected from wind and precipitation. A deep bed of straw or corn stalks that calves can nestle into will help them preserve body heat.

A good rule of thumb for determining the proper bedding depth is if the calf’s legs are completely hidden while she’s lying down, the bedding is deep enough. While sand, sawdust or shavings are optimal bedding choices for the summer months, these options are poor choices for the winter since they provide no protection to the calf.

Maintain a clean and dry bedding area by regularly removing wet or soiled particles and replacing it with enough clean bedding. A clean environment for calves will help decrease their exposure to a variety of disease-causing bacteria and pathogens.

Calf jackets or blankets can also be used to help keep the calves warm, dry and healthy. Jackets or blankets should be used on newborn calves if the temperature is below 60 degrees. Calves older than 3 weeks won’t need a blanket unless the temperature is below 41°F.

Be sure the jacket or blanket fits snuggly to the calf so it properly covers the main surface area. It’s important to adjust the jacket as the calf grows to prevent any discomfort and ensure that it’s providing proper coverage. It’s also important to monitor the jackets for cleanliness and replace soiled or wet jackets with a clean, dry one.

Whether calves are raised in hutches, greenhouses or individual pens inside the barn, your calf- housing system is contingent upon proper ventilation, isolation, and comfort. Proper ventilation must be watched carefully, especially in winter months.

Our natural inclination is to keep calves out of drafts and breezes. While that is good, it’s even more important to promote air movement and remove moisture and ammonia build-up. Excess moisture and ammonia cause respiratory problems and make calves more susceptible to pathogens.

Since calves are born with immature immune systems, fresh air is critical for keeping them healthy. Ensuring comfort for your calves will help them better utilize the nutrients in their diet for growth instead of dealing with their environment.

Cold stress weakens a calf’s immune system, making her more susceptible to diseases such as navel infections, calf scours and pneumonia. Scours are especially prevalent during the winter months and cause electrolyte loss and dehydration.

Primary treatment should be geared toward restoring the water balance by administering electrolytes fed at body temperature. Continue feeding the calf her normal milk replacer, which will continue to provide the energy the calf needs for regular maintenance and growth.

Early response to diseases is critical as they are likely to inhibit a calf’s ability to reach proper growth targets, which will impact her future success in the milking herd. Work with your veterinarian to identify early symptoms and determine treatment protocols before the disease worsens or spreads to other calves.

Although adding extra feedings and around-the-clock care may seem like a lot of work, especially during the nasty winter months, you are providing your calves with the tools they need to overcome cold stress and develop into healthy, well-grown heifers that will impact the future productivity and profitability of your milking herd. PD

Susan Day
Young Animal Technical Manager
Land O’Lakes Purina Feed