Why use a calf jacket?

Why use a calf jacket?

Far from a fashion item, calf jackets help young calves stay warm, healthy and reduce the risk of disease. Calves are the future of your herd and a good start is essential.

Why does a calf need a jacket?

The simple answer is to keep warm in cold weather. But, what’s “cold” to a new born calf?

There is a temperature range where the amount of body heat produced by a calf is balanced by her body heat losses. That range is called “thermo-neutral.”

For an 40kg calf this range is around 12 – 21c, assuming she is dry and draft-free. As temperatures fall below 12c, she has to burn extra energy to maintain her body core temperature.

There are four ways heat escapes from a calf – no matter what the weather or season.

1. Evaporation
Heat from her body is used to evaporate water primarily on her skin and hair coat. This is easy to solve at birth. After her dam licks her off, just finish the drying and fluff up her coat. But, does her housing during the first month provide a dry place to keep out of rain and snow? A water repellent jacket can keep her dry.

2. Conduction

This is another way heat moves away from a calf. Most calves less than a week old spend ninety percent of their time lying down? Dry wood shavings? Dry straw? Wet bedding?

Direct contact with wet straw results in three times as much heat loss (conduction) as contact with dry wood shavings. A moisture repellent jacket can slow down conduction heat losses through damp bedding

3. Radiation
Losses occur when heat is transferred through the air from a warm object (calf) to a cold one (concrete, snow). These losses are reduced for calves if they can lie down some distance away from the cold object. A jacket can serve as an insulating barrier to reduce heat moving away from the calf’s body.

4. Convection
Losses occur when air passes over the calf’s body. On one hand, when the housing is draft-free and a calf can snuggle down into a bed of straw, these losses are minimal.

On the other hand, when the bedding does not allow any hollowed out nest and the pen is wide open for air movement, convection losses can be higher. A calf jacket can serve to minimise heat loss by radiation that is subsequently carried away by convection.

How do Jackets benefit the calf?

To summarise, they reduce heat loss, stress which in turn increase food conversion, comfort, and DLWG.