Temperatures Go Pear Shaped as Autumn Arrives
UK - Continuous real-time recording of what happens in pig buildings continues to demonstrate how wrong we are if we think we're giving our pigs a "controlled" environment.
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The screen capture (shown below) of temperatures from a grower house over the last few days (September 19-24) shows what happens when autumn weather arrives.
The beginning of the trace shows the house temperature was reasonably close to the set temperature - rising a few degrees above set when outside temperature reached target temperature, but maintaining target temperature at night when outside temperature fell.
But then the weather changed and night time temperatures were far lower. As a result, in the last couple of days the temperature in the building fell to only 3-4ºC at around 4am.
If you compare inside and outside temperature you'll see that it's only around 10ºC warmer inside than outside.
If the set temperature is 21ºC, this would indicate the house can only maintain set temperature as long as it is 9ºC outside (or warmer), but as soon as it falls below that, inside temperature drops pretty well directly in line with outside temperature.
If you test the controller you'll find it's working perfectly according to its settings. So what's gone wrong?
The problem is the minimum ventilation rate versus the heat output of the pigs in the room, according to Nick Bird of Farmex. In other words the ventilation system is trying to remove more heat than the animals produce.
Further Information
To read the full report, please click here (PDF Format)
Source: National Pig Association - 25th September 2003