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Is your calf housing fit for purpose?
Calf housing can be new-build, an older shed or adapted from an existing building but while they differ in structure there are fundamental basics that should be common to all.
When it comes to baby calves, rearers must understand what the animals need from their housed environment otherwise health and development won’t be truly optimised.
Floor space
Floor space is often overlooked in calf accommodation but providing calves with plenty of room will reduce disease pressure and unwanted stress, and promote positive social behaviour and calf comfort.
There are legal minimum requirements on floor space, set out in AHDB guidance:
- For calves with a liveweight of less than 150kg, allow at least 1.5m2 per calf
- At 150 – 200kg liveweight, 2m2 per calf
- For calves with a liveweight of more than 200kg, at least 3m2 per calf
Solid barriers between pens
Research by Lago et al. (2006) found that creating a single solid barrier between calf pens reduced prevalence of respiratory disease.
This study suggested that the ideal calf pen should be 3m2 or bigger and have solid panels on either side to separate each pen from the next.
Throughput of calves
On some farms, individual pens are used for the first few days or weeks of life so that calves can be closely monitored until they are well used to drinking milk.
Quite often however, limited availability of individual pens means they are not sufficient in number for the throughput of calves.
When pens are overused, pathogens build up and increase the risk of disease in the immunocompromised baby calf. Microbes constantly multiply when there is a continual source of nutrients and the environmental conditions, such as temperature, pH, and oxygen levels, exist for them to proliferate.
Having extra capacity allows pens to be properly cleaned and disinfected between occupancy.
Alternatively build individual pens within a group pen.
Group size
Less is more when it comes to group size – around 10 calves per group is the ideal.
The fewer the calves the less the competition for feed and the lower the risk of disease transmission. It is also easier to monitor calf health in smaller groups.
Hygiene
Preferably, calf houses should be accessible by machinery to make it easy to clean pens regularly between occupancy to prevent disease build-up. Failure to provide clean accommodation often leads to common issues in baby calves i.e. Naval ill, joint ill, scours (Infection entry through mouth, nose & naval).
Ventilation
Good airflow is important for baby calves, to remove stale air from the building without creating draughts that may cause a chill.
To achieve this, the recommended air speed at calf level is 0.20 metres/second.
Stagnant air contaminated with dust, moisture, ammonia and viruses can cause pneumonia, so this must be removed and replaced with fresh air.
There is a rule of thumb that calves should have a minimum of 7m3 of air each, which can be established with the following formula:
Depth (m) × width (m) × average roof height (m) = volume.
Volume ÷ 7m3 = total number of calves based on cubic air capacity
Housing baby calves in a separate air space from older animals is advised to avoid spread of disease to the more vulnerable younger calves.
Temperature
Calf housing can be colder than is desirable for baby calves that have a thermo-neutral zone of around 13-25°C in their first month of life.
Tall sheds aren’t the best for this purpose as they often tend to be colder, but they can be modified to create a microclimate, by constructing a false roof or canopy for instance.
A canopy gives calves the option of lying beneath it to keep warm and dry.
Bedding is very important when it comes to keeping calves both comfortable and warm.
Straw is a great insulator and therefore more often than not the number one choice.
A nesting score system was developed at the University of Wisconsin to evaluate the adequacy of bedding:
Score 1 = calf legs are fully visible
Score 2 = calf legs partially visible
Score 3 = calf legs are obscured by bedding.
Aim for Score 3 when it comes to nesting to ensure calves are cosy and comfortable. Providing a light layer of fresh bedding daily also helps create a barrier between bugs and the calf. Research has shown calves in bedding with a nesting score of 3 have a much-reduced risk of respiratory disease compared to 1 and 2 (Lago et al., 2006).
Drainage
Moisture creates the perfect environment for disease-causing pathogens to survive and will also make calves feel cold.
A 5% slope in the floor will allow good drainage and therefore prevent pens from getting wet.
For a floor with no slope and therefore no opportunity for run-off, extra bedding is needed. Another option is to place woodchip, stones or slats under the straw bedding to create a barrier between the calves and moisture and ammonia.
A floor that slopes to the side allows the option of creating channels between the pens to capture the run-off and carry it away.
Take-home tips
- Provide a floor space of 2-3m2 per calf
- Erect a solid barrier between pens to reduce risk of respiratory disease
- Provide ventilation without causing a draught at calf level
- Aim for nesting Score 3 in deep dry bedding
- Establish a 5% floor slope to drain moisture
- Always clean pens between calves
- Have more pens than needed to allow for disease control
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