Dr. Grazyne Tresoldi, Assistant Professor, Animal Welfare, Department of Animal Sciences, The Ohio State University
As winter approaches, low ambient temperatures and high humidity pose serious challenges for all calves, with very young ones being especially at risk. When temperatures drop below 50°F, calves must expend extra energy to maintain their body temperature. This increased energy demand can quietly lead to slower growth, weakened immunity, and higher susceptibility to disease. If calves are unable to cope with the cold, they may exhibit signs of stress, such as shivering, reluctance to stand, and frostbite on extremities. In severe cases, cold stress can be fatal.
Here are research-backed and practical strategies to mitigate cold stress and protect your calves:
Optimize Housing
- Provide windproof, draft-free shelters, such as well-ventilated hutches or barns. Remember, draft-free doesn’t mean airtight - ventilation is critical to reduce humidity and airborne pathogens that can worsen respiratory issues.
- Use deep, dry straw bedding to insulate calves and allow for "nesting," where calves can burrow for warmth. Replace bedding regularly to prevent moisture buildup, which compromises insulation.
- House calves in pairs or small groups to enable huddling (Figure 1), which improves thermal comfort through shared body heat.
- Consider overhead heat lamps, especially for newborn calves, to provide targeted warmth in colder conditions.
Adjust Feeding Strategies
- Increase milk or milk replacer allowances during cold weather to meet higher energy demands for thermoregulation and support growth.
- Consider ad libitum feeding; calves will self-regulate their consumption based on energy needs. In colder conditions, their intake may exceed the average of 15 to 20% of body weight daily. For group-housed calves, automated feeders can help ensure consistent access to sufficient milk or replacer.
- Incorporate liquid fat into diets as an option but consult a nutritionist to ensure the crude protein to metabolizable energy ratio is balanced.
Provide Layers
- Use insulated calf jackets to retain body heat and conserve energy for growth and immunity (Figure 2). Ensure jackets are clean, dry, and properly fitted to avoid restricting movement or creating pressure points.
Engage with Experts
- Collaborate with veterinarians, nutritionists, and educators to design a cold stress management plan tailored to your farm’s unique needs. Routine assessments of housing, nutrition, and calf health are essential to prevent issues before they arise.
By implementing these strategies, Ohio dairy farmers can help their calves stay healthy and thrive throughout the winter, fostering robust growth, development, and improved welfare within their herds.
Sources:
1. Roland et al., 2016. https://doi.org/10.3168/jds.2015-9901.
2. Van Os et al., 2024. https://doi.org/10.3168/jdsc.2023-0443.
Figure 1. Pair-housed calves with access to two hutches often prefer to huddle together in one hutch during winter, conserving body heat. Photo credit: Kimberly Reuscher.
Figure 2. Calf jackets are an effective way to reduce heat loss during cold weather, helping calves conserve energy. They are also machine washable for easy maintenance. Photo credit: FutureCow.