KEEPING HER WARM
The thermoneutral zone of a newborn calf is between 55-78° Fahrenheit. When the temperature drops below 55, a newborn calf is going to begin to experience some degree of cold stress. The first step in winter feeding is to create a comfortable environment.
- BEDDING Between week 1 and week 6 of life, a calf spends 73-81% of her time lying down. Due to the fact that she is spending close to ¾ of her time lying down, it is crucial that we provide her clean dry bedding. Keep in mind that the rate of heat transfer in wet bedding may be 3 to 10 times that of dry bedding. Ensure bedding is dry where calves are lying and supply straw allowing calves to nest. Check to make sure there is enough bedding underneath the calf so she is not losing heat through the ground.
- CALF JACKETS Putting a jacket on a calf can help decrease heat loss by up to 15%. With the combination of dry straw bedding and calf jackets we can reduce heat loss by up to 30%.
- HOUSING Whether calves are housed in a barn or outside we need to be sure they are well ventilated yet draft-free. You may need to close vents in hutches or raise curtains on condos to reduce draft. Ventilation in calf barns may need to be adjusted from what was working in the summer months to diminish drafts in the winter. Protect calves from lying against concrete walls which can absorb her heat.
- NEWBORNS Get newborn calves dried off quickly to prevent immediate cold stress. The use of a warming box or heat lamp can help (as long as they are kept clean). Give calves good quality colostrum quickly. Monitor temperature of the colostrum to ensure it is being fed at nothing below body temperature.
- CHECK YOUR SYSTEM:
- Go into a pen where you see a calf has been lying down.
- Kneel down on one knee for at least a full minute.
- If your knee gets warmer it is ok, if your knee gets colder the calf is losing heat down into the ground. In this case more bedding should be added.
- Feel if there is any draft where you are kneeling.
- Check to see how dry the bedding is in that exact spot where she has been lying.
FEEDING CALVES FOR WINTER ENERGY NEEDS
As the temperature drops our calves require more energy for maintenance. Unlike older calves who can just eat more grain, young pre-ruminant calves do not have that option. Calves under three weeks of age are particularly stressed because they do not have much energy stored (3-4% body fat) and are eating very little calf starter. For every 1 degree drop in temperature below 50 F, a calf requires one percent more energy. By the time the temperature reaches zero, a calf should receive 50 percent more energy (calories) just for maintenance.
So what are the options for cold weather feeding?
- FEED LARGER VOLUMES OF THE SAME MIX
- If you would like to stay with the same mix, you can feed larger volumes to increase the calf’s caloric intake.
- Feed at least 3 quarts or 3 ½ quarts per feeding of milk or milk replacer at recommended solid levels.
- This also allows calves to get more water, decreasing chances of winter dehydration.
- ADD AN EXTRA FEEDING
- If you have the ability, adding an extra feeding has proven to be very successful.
- To save time, you can target younger calves (~three weeks and younger).
- Make sure you time feeding accordingly and stick to a routine once you start.
- INCREASE THE AMOUNT OF POWDER
- You can increase the solid level to 15-18% solids.
- Ensure you have free choice water available because calves may be thirsty due to the increased dry matter content.
When feeding calves in winter be very aware of the temperature at which you are feeding the milk. Milk or milk replacer should be fed at 100°F- 102°F. If it is any colder calves will have to use energy to bring milk back up to body temperature. Often calves fed last will get much colder milk than calves fed first; In this case you may have to adjust your mixing temperature a little higher.
Watch for winter dehydration. It is very important that you still feed free choice water to calves in the winter months. We all know that it is crucial for grain intakes, but it also helps prevent calves from getting dehydrated in the winter, especially if you increase solid content.