The requirement for additional energy management in a calf house varies according to the calf/calves, the weather, and the quality of the calf house environment. In the first week of life a calf is likely to spend extra energy to keep “warm” below an air temperature of maybe 10⁰C. The actual lower critical temperature for any one calf will depend on all those aspects that will influence the energy dynamics of the system:
Calf Jacket benefits
- Genetics – Jersey calf will feel “cold” before e.g. Charolais calf
- Birth conditions – normal/prolonged; premature/low birth weight; single/twin
- Health – vigour/health vs apathetic/low feed intake
- Nutrition – quality and quantity and timing of colostrum; energy density and dilution of milk powder, adequate intake
- Air speed – less than 1m/s is good; a draft is negative
- Dry bedding – essential; damp bedding extracts energy from the calf
Calf Jacket protocol
Jackets must be made of breathable materials.
- Locate max/min thermometer in calf house
- Reset thermometer every morning during autumn/winter housing
- Decide on set temperature for your system, eg 10⁰C
- Agree starting protocol with staff: eg. 3 consecutive night-time minimum temperatures below e.g.10⁰C
- Calves must be dried off before using jacket
- Place clean jacket on every calf below one week of age and on entry to calf house or a soon as dry after birth.
This is entirely dependent on the energy dynamics listed above; what is the condition and appetite of each calf? What are the expected weather conditions? OR keep on calf until 4 weeks old. Can be left on longer if needed with no ill effects as long as it fits comfortably.
- Know the weather forecast; steady or rising temperatures OK, falling temperatures, beware removing jacket too early
- Agree with staff a temperature protocol for healthy calves e.g. one week old >10⁰C OK; two week >5⁰C OK; more than 3 week >2⁰C OK
- Refer to recent night-time minimum temperatures
- Consider individual calf condition; feed intake, health, growth rate
- Remove jacket in morning not afternoon
- Breathable jackets can be left on even with daytime temperatures unto 19-20⁰C if night time temperatures fall below 10⁰C
- Remove excess dirt from jacket with hose/light powerwash or pre-soak
- Wash jacket at 40-50⁰C with detergent and dry.
- Line dry or dry overnight in aired room. Do Not Tumble Dry.