Winter Calf Health
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With colder weather quickly approaching, it is important to start to think about what additional management procedures will be necessary in order to maintain appropriate calf health during the winter months. Knowing what you can do as a producer to minimize calf losses by providing proper housing, nutrition, and individual care/attention is vital. Depending on the age of the calf, their ability to handle changes in temperature and “cold stress” will vary. The thermoneutral zone of a newborn calf up until 4 weeks of age is between 10-250C in comparison to 0-250C for older calves. Therefore, temperatures outside these ranges will result in calves using more of their own energy stores in order to keep warm, which will inhibit growth (resulting in <1.5 lb/day gains) and compromise immune function predisposing them to respiratory infection. Signs to look for in calves experiencing hypothermia include shivering, rapid breathing, raised hair, and cold and pale extremities.
In order to keep calves dry and warm, minimizing the exposure to wind, precipitation, and providing additional bedding especially for those out in hutches, is imperative. The use of straw over shavings is highly recommended for the fact that calves will have to ability to nestle, or bury, them-selves in the straw to reduce heat loss. An easy way to see if there is enough bedding is the kneel test. If your knees get wet after kneeling on the bedding for 15-20 seconds then additional bedding or cleaning is required. Calf coats are also beneficial in reducing cold stress and they can be easily laundered between calves and have long lifespans. Additionally, providing proper draft free ventilation is important in reducing airborne bacterial counts, ammonia levels, dust, humidity, and incidences of pneumonia. One way this can be achieved is by installing positive pressure ventilation systems. These ventilation systems are able to introduce fresh air (15cfm per calf) without creating a draft. Also, reducing stocking density will reduce bacterial counts and having solid panels in group pens situated away from a cold outside wall will provide an area where calves can lay down and be protected from drafts and reduce drawing heat away from the calf.
Having up to date calving protocols are also of great value. Newly born calves should be quickly wiped down with towels and kept dry especially in the first two hours after birth. After being moved to a hutch or pen, holstein calves should ingest at least 4L of high quality colostrum resulting in the calf receiving 200g of IgG in the first six hours of life. Remembering to keep frozen or powdered colostrum on hand is also beneficial. Calves are creatures of habit and expect consistency in terms of when they are being fed. However, with temperatures dropping to -200C, especially overnight, calves’ rations need to be adjusted by either increasing the number of feedings or increasing the amount fed per feeding. Newborn calves have very little energy reserves which can become depleted in approximately 18 hours. So, by having at least 20-22% of fat in the ration, it will aid in preventing hypothermia while allowing the calf to gain weight.
A couple good rules to remember are:
- Calves that are found shivering after being fed are not being fed enough
- Feed calves at least 10% of their bodyweight
- Give an extra 39g/day of milk or milk replacer for every 50C drop
- OR increase the amount of feed by 2% for every degree the temperature drops below 50C
- Provide access to free choice water served at body temperature (38.60C) and high quality starter
- Have electrolytes on hand in order to prevent dehydration in the event of any scour outbreaks
By following these steps, you will be able to maintain your calves health, growth and well-being throughout the upcoming winter months. Calves are the future of your dairy, and giving them the appropriate care during this critical time in their lives is essential for their long term success on the farm.