Caring for Calves in Cold Weather
As the temperature drops in many parts of the world with the arrival of winter, the nutrient needs of calves are increasing. Just like humans, calves attempt to keep a constant body temperature, no matter what temperature it is outside. Calves can maintain their body temperature without needing extra energy, in a temperature range called the thermal neutral zone. For the first month of life calves are most comfortable in temperatures between 50°F to 78°F (10°C to 25.6°C). Calves older than one month of age are most comfortable between 32°F to 80°F (0°C to 26.7°C).
Once the temperature reaches the lower critical temperature (LCT), 50°F (10°C) for calves older than one month of age, and 32°F (0°C) for calves less than one month of age, the energy they consume is now used for maintenance and less energy is available for growth and immune function. Increasing intake of milk, grain, and water will benefit the calf in cold weather. Also keeping calves dry, well bedding, and protected from drafts will help them stay healthy and growing during the winter.
Calves are born with only a small amount of body fat. During cold weather it is crucial to ensure calves receive enough nutrients to keep themselves warm, continue to grow, and avoid depressing the immune system. Consider the following areas in your winter calf nutrition program.
- Water is an essential nutrient necessary for metabolism and hydration of the body. During cold weather water intake is very important to calves for rumen development, digestion, and eliminating waste. Milk is not a substitute for water. Calves should consume 10% of body weight in water per day. It can be difficult to keep water in front of calves as it freezes during cold weather. To ensure calves receive adequate water, give warm water (102°F or 38.9°C) within 30 minutes after feeding milk, and a third offering of warm water during the day if needed. Calves less than one month of age should receive one gallon of water per day and calves older than one month of age should receive 2 gallons of water per day.
Milk volume is often limited for young calves in an attempt to encourage starter intake. In cold weather it may be necessary to increase the amount of milk to ensure the calf is receiving adequate nutrition to keep itself warm, continue to grow, and avoid depressing the immune system. Here a few strategies for increasing milk volume during cold weather.
- Feed more fat, a trail completed at the University of Minnesota showed that adding ¼ pound (113.5 grams) of supplemental 60% fat increased growth rate during the first 3 weeks of life. Overfeeding fat can lead to depressed grain intakes, it is important to only add supplemental fat in the first three weeks of the calves’ life.
- Add a feeding late at night to increase milk intake and allow the calf to have a full belly during the cold and dark night.
- Increase milk volume by 1/3 divided across 2 feedings. This may work best for farms limited on labor when a third feeding is not possible. Monitor calves to make sure they do not have any digestive upsets with the larger meals.
- Increase milk solids by adding more powder to your mixture or by boosting whole milk with milk powder. Speak with you nutritionist about the amount of powder you would need to add. Total milk solids should not exceed 15%.
- Starter is another energy source for calves. Early starter consumption will have a positive effect on their ability to withstand the cold. Ensure that calves always have free access to starter beginning by day 3 of age. Make sure starter is always clean and fresh. Keep buckets somewhere calves can easily access and no higher than 20 to 40 inches (0.5 to 1 meter) off the ground.
The environment has a big influence on the LCT of the calf. Drafts can chill than calf and in turn radiate heat from the sun can help to warm the calf. Keep these things in mind when choosing housing for your calves.
- Housing should be draft free, but still have proper ventilation and air flow.
- Bedding needs to be clean and dry to aid the calf in retaining body heat. Straw is the best bedding source for cold weather. Bedding should be deep enough it will cover the calf’s legs when they are lying down.
- Sunlight can help to warm calves. Place hutches in a manner that the calf will be able to catch some sunlight for most of the day.
- Blankets can be used to insulate young calves. Be sure that calves are not sweating in the blankets during the day. Wet hair will quickly chill calves when the temperature drops at night. Blankets are most beneficial for calves less than 3 weeks of age.
Changes during cold weather take more time and effort. Monitor calf intakes, health, and growth to determine what changes you may need to make. Continue to monitor calves after implementing a change to quantify the benefit. Remember the gold standard is for calves to double birth weight by 56 days of age. This is possible even during cold weather.
Written by: Mariah Gull, M.S.