Good calf and housing management are essential to achieve performance targets, writes CAFRE’s, Richard Gibson.
The main areas farmers should address are:
- Air speed;
- Moisture level;
Calf management: Hygiene
Farmers should thoroughly clean the shed and disinfect with a broad-spectrum disinfectant before calves are born.
While in use, disinfect pens frequently to prevent the build-up of disease organisms.
The flooring/bedding should allow for easy cleaning and removal of waste. Ideally, you should bed calves every day and clean out pens weekly.
Fresh air delivery should come from natural ventilation, and you should provide an additional fan ventilation if necessary.
If natural ventilation is insufficient to provide adequate fresh air during the critical periods of damp, calm weather, install a fan and duct system.
Only use an extractor fan system in buildings with a low volume and a small number of wall inlets.
Fan and duct ventilation systems are inexpensive to buy and operate and provide fresh air to all corners of a building. A calf house should have at least six air changes per hour.
Micro-organisms die quicker when relative humidity is below 80%. However, relative humidity levels above 85% could occur during damp, dark days. Air space is also critical in calf housing.
Also, provide a minimum of six cubic metres total air capacity per calf at birth, increasing to ten cubic metres by twelve weeks of age.
The more calves in a single air space, the greater the risk to health.
Fresh air is an essential requirement for good health, but you must avoid draughts at calf level.
Fresh air delivery picks up aerial contaminants such as dust, fungal spores, gases, and airborne pathogens. Also, it is an excellent biocide.
Fresh air kills airborne bacteria and viruses ten to 20 times quicker than stale air.
You can control this using sloped floors that ensure good drainage, fixing any leaks and good ventilation.
Providing calves with a dry lying area by using a deep bed of straw will also help. Straw is superior to other bedding materials in terms of insulation value.
It has a high ‘nesting score’, which provides a preventative effect against calf respiratory disease in naturally ventilated sheds.
Straw bedding should be at least 15 cm deep and kept dry at all times.
To reduce the amount of heat lost from calves, their legs should not be visible when lying in the straw, especially during cold weather.
Waste should not drain from one pen through another as this can spread disease.
Improve drainage on concrete floors by having at least a 1:60 slope towards a channel.