Temperature control is still poor on many pig units and production and health are affected.

Air temperature can affect growth performance mainly through its effect on feed intake if the pig is outside its thermal comfort zone. The critical time for temperature control is the post-weaning period when the pig’s feed intake is low as it adjusts to the new environment.

In colder conditions the older pig can adjust somewhat by increasing feed intake to increase energy input. But post-weaning, the pig cannot compensate with higher feed intakes and this results in reduced body insulation, and poorer pig performance.

Piglet health 
Piglets were weaned at 28 days with a weaning weight of 6.64 kg and weaned into either a pen with a heat lamp or pen without a heat lamp. Room temperature was maintained at 21°C while those pigs with a heat lamp were maintained at 29°C. The outcome was that after 10 days the pigs at 21°C grew 33% less and consumed 53% more feed than those pigs maintained at 29°C.

This shows the importance of ensuring that the pig remains in the comfort zone thereby
optimizing pig performance. As producers, we often do not know what the temperature is at the pig level and not only is the average temperature important but the daily temperature variation. Studies (Kurihara et al, 1996; Le Dividich, 1981) have shown that large daily temperature variation (minimum and maximum) has a negative impact on performance. Kurihara et al (1996) compared pigs at an average of 58 days in a constant environment of 21°C with pigs that had a variation of 3°C around 21°C and pigs that a 6°C variation around 21°C.

The feed intake of the piglets was reduced by 14% under the high fluctuating conditions while there was a 3% reduction in the low fluctuating conditions resulting in poorer performance in both treatments.

It is therefore important to not only provide the correct temperature but with a minimum variation throughout the period and although limited data the minimum variation would be < 3°C.