The most important factors relating to pen climate are:
- pen temperature
- air humidity
- air movement
- air composition
Pen temperature
The same compatibility conditions apply for all age categories mentioned in the table. The absolute temperature is not so important. As a general rule: the pen should be so fresh that it should not be possible to ‘smell’ the calves. An absolute precondition is that the animals must be able to lie down on a dry and isolated floor.
Try to keep temperature fluctuations as small as possible. Temperature differences of more than 5°C in close vicinity to the calf, e.g. between day and night, could lead to lung problems. In particular, cold spring and autumn nights, after a relatively warm day, are dangerous
Air humidity
Try to maintain the air humidity at around 60%. If the air humidity is too high, it increases the possibility of lung problems.
Air movement
An absolute condition for a good pen climate is the absence of drafts around the animals. This means the air flow speed in the close vicinity of the calves should not exceed 0.25 m/sec. High air flow speeds cause draughts, especially when there is a clear temperature difference between incoming air and the ambient air around the calf. This increases the chance of lung ailments.
An effective method is to allow cool, fresh air to flow in through the feeding inlet, extracting the exuded air via the roof. If this is not possible, the incoming air should be guided in such a way that contact with calves is avoided.
Draughty windows etc. above the calves are particularly dangerous during cold weather. Even draughts under the grills should be avoided, since ammoniac vapours could reach the calves.
Air flow speed is closely connected with the ventilation capacity and the size of the inlet openings. The following standards apply:
- air inlet opening: 4 cm² per m³ ventilation capacity
- for details of ventilation capacity, see the table below
Required ventilation capacity
|
Age
(months)
|
Average
weight (kg)
|
Ventilation capacity (m3/animal/hour)
|
|
1
|
60
|
60
|
|
3
|
100
|
100
|
|
6
|
175
|
170
|
|
12
|
305
|
245
|
|
18
|
425
|
330
|
|
22
|
500
|
400
|
Source: IKC
Even when the ventilation arrangements meet these standards, there may still be a draught. This could be caused by the location of the blower and/or the inlet openings.
In areas where the climate permits, natural ventilation is always preferable to mechanical ventilation, though pens must then be constructed differently
Air composition
The composition or quality of air is obviously of the greatest importance. There should be a sufficient inflow of fresh air and adequate removal of ‘spent’ air containing harmful gases, dust and germs/pathogens. Good (natural or mechanical) ventilation is therefore a necessity.
|
