When dairy farmers think about animals impacted by cold stress, calves are often the first that come to mind. Their smaller size and limited fat reserves make them especially vulnerable to harsh winter conditions. However, it’s important to remember that cold stress doesn’t just affect calves—it can also significantly impact heifers.
Younger animals, like post-weaned heifers, are particularly susceptible as they have less developed coats, and higher energy needs to maintain their core body temperature. For dairy farmers, understanding the signs of cold stress and implementing preventative measures across all age groups in the herd is essential for maintaining health, productivity, and growth during the winter months. While calves often receive extra attention, ensuring proper care for heifers and older animals can make a big difference in the overall success of the operation during the colder seasons. For these replacements to grow and thrive, dairy farmers must take proactive steps to prevent cold stress and minimize associated health issues.
Daniela Roland, dairy extension educator at Pennsylvania State University, provides the following tips for providing adequate care to replacement heifers during frigid temps.
Understanding Cold Stress
While lactating cows are relatively tolerant of cold temperatures and can handle conditions below 18°F when equipped with a heavy winter coat, young heifers face challenges at temperatures below 32°F.
“Normally, a heifer’s winter coat, plus their natural metabolic processes, like rumination, can keep them warm,” Roland says. “But during extremely cold temperatures - especially if there is inadequate housing, lack of dry bedding, insufficient nutrition, or a combination of these - heifers may experience cold stress.”
Housing and Bedding
Dry, well-bedded pens are essential to help heifers tolerate winter conditions. Bedding materials like straw, shavings, or corn fodder should be clean, dry, and absorbent to retain body heat.
“One way to test the dryness of heifer pens is the knee test,” Roland says. “To do this, try dropping to your knees in several areas around the pen. If your knees are still clean and dry after 10–15 seconds of kneeling on the bedding, then the bedding is sufficient. But if your pants are dirty or damp, more fresh bedding should be added.”
Wet or muddy coats reduce the insulating properties of a heifer’s hair, also increasing their susceptibility to cold stress. Excess manure or mud buildup should prompt farmers to add fresh bedding or clean pens more frequently.
Additionally, heifer housing should allow for adequate air exchange without creating drafts. Insufficient ventilation can increase the risk of respiratory diseases like bovine respiratory disease (BRD), which costs farmers an average of $252 per case and can delay a heifer’s growth and first calving, according to Roland.
Proper heifer housing is another critical factor to consider during cold weather. Housing should shield heifers from environmental extremes such as harsh winds, heavy snow, and freezing temperatures while maintaining a comfortable and healthy environment.
One key aspect of housing is ventilation. While barns and shelters must prevent drafts, they should also allow for proper air exchange to reduce humidity and prevent the buildup of harmful gases like ammonia. It’s essential to monitor heifers for signs of respiratory distress, such as coughing, labored breathing, or nasal discharge, as these could indicate inadequate airflow or other health issues. If respiratory problems are detected, improving ventilation should be a priority.
Heifers housed outside also need special attention.
“Heifers housed outdoors need to have access to either natural or constructed windbreaks,” Roland adds. “Wind significantly reduces the actual temperature, increasing cold stress on heifers.”
Nutrition for Winter Growth
In colder weather, heifers expend more energy to stay warm, making proper nutrition vital. Farmers should aim for daily growth rates of 1.75 pounds for large breeds and 1.3 pounds for smaller breeds to ensure heifers reach optimal breeding size.
“Data has shown that undersized heifers may calve later than the desired age range of 22 to 24 months. These smaller heifers tend to be more prone to calving problems and less productive,” Roland says. “Farmers should work with their nutritionist to make sure that their heifers have enough energy in their diet to help protect them from the cold weather and to ensure proper growth.”
Water Access
Water availability is another critical factor in winter care. Frozen or excessively cold water can limit intake, reducing feed consumption and energy availability.
“Dairy heifers between the ages of 5 and 24 months will drink about 3.8 to 9.6 gallons of water per day,” Roland adds. “Monitoring for frozen waterers is important during the extreme colder temperatures.”
Why It Matters
Investing in proper heifer care during winter ensures these replacements grow to their genetic potential and transition into productive lactating cows. By focusing on housing, bedding, nutrition, and water, farmers can safeguard their herd’s health, prevent growth setbacks, and optimize future productivity. Taking these steps helps ensure your heifers thrive, even in the coldest months.
