When winter temperatures turn cold, calves will require a lot more energy. The thermal neutral zone (comfort zone) for newborn calves is 50-78°F, while month-old calves have a thermal neutral zone is 32-78°F. Once the temperature reaches below the lower critical temperature of 32°F for month-old calves or 50°F for newborn calves, the energy they consume is used for maintenance, making less available for growth and immune function.
Strategies to deliver needed, additional nutrients to preweaned calves in cold weather include:
- Feed more fat. A University of Minnesota trial showed adding ¼ pound of a 60% supplemental fat increased growth rate during the first three weeks of life. However, feeding too much fat can decrease starter grain intake. Only use supplemental fat for the first 14 days of life, and gradually wean calves off.
- Feed more milk or milk replacer. There are three ways to feed more milk replacer:
1) Add a feeding. Feeding a third meal will increase amount of solids by 1/3 compared to feeding only twice daily.
2) Increase volume. Increase the feeding volume by 1/2 between the two feedings. This is the same as adding a third meal. However, these larger meals can decrease starter grain intake and cause digestive upset.
3) Increase solids. Another way to feed more milk replacer is to add more powder to the volume of milk replacer mixed. One should consult with your nutritionist to determine amount of powder to add to increase energy. However, total solids in milk replacer should not exceed 15%. Anything greater can cause health risks.
- Feed more starter or get calves on starter sooner. Starter grain provides another source of energy for calves. Begin offering starter at 2 to 3 days of age. Calves should begin eating some starter by 5 to 7 days of age. By the second week, calves should be consuming ¼ to ½ pounds per day. Before weaning, a calf should be eating starter for at least 3 weeks and should be eating 2 pounds of starter for 3 days in a row.
- Use warm water, not cold. Water is essential for maintaining body fluids, rumen development, digestion, and eliminating waste. Calves should consume 10% of body weight in water daily. Because milk intake does not substitute for water, provide supplemental water. Feed water that’s been warmed just above 1020 F within 30 minutes of feeding. Free-choice water should be given. Calves should consume at least 1 gallon of water per calf per day for the first month of life and 2 gallons during the second.
For more information regarding heifer management please visit UW-Extension Heifer Management.
Read Binversie’s winter feeding recommendations in greater detail here.