Healthy temperature ranges for pigs
Pigs are more susceptible to cold temperatures when they are young and to hot temperatures when they older (as heavy growers and adults).
Ideal temperature ranges
The ambient temperature range that suits your pigs' comfort and productivity is called the 'thermoneutral zone'. In this zone, your pig's heat production is determined by its live weight and feed intake because it is not affected by air temperature.
This is generally between 15 and 30°C but depends on:
- flooring type
- air flow
- skin wetness
- whether pigs are group housed.
The pig welfare code lists the lists the optimum temperatures for pigs at different stages.
Keeping pigs cool
The top limit of the thermoneutral zone is called the 'evaporative critical temperature' (ECT). If your pig's temperature goes above the ECT, your pig overheats and it will:
- avoid body contact with pen mates
- eat less
- foul areas of its pen that it normally keeps clean, then possibly lie in this and other wet areas
- pant more than 50 breaths a minute (this cools their bodies through evaporation from the lungs).
The 'upper critical temperature' (UCT) is the highest possible temperature your pig can reach before it starts to get serious health problems. The UCT is generally 6–8°C above the ECT. Your pigs will become severely distressed if their temperature rises above the UCT.
Avoid heat stress
Observe the pigs' behaviour, especially lactating and pregnant sows, for signs of heat stress, such as panting.
Then, lower their temperature by:
- increasing airflow
- wetting their skin
- giving ice licks.
Drip or spray cooling
If there is good airflow at pig level, you can reduce heat stress in dry climates by drip or spray cooling.
Keeping pigs warm
The lower limit of the thermoneutral zone is set by the 'lower critical temperature' (LCT).
Piglets and weaners suffer from cold more than older pigs. The best temperature for your newborn piglets is between 27°C and 35°C. You can lose piglets if the temperature falls below 16°C. Below 2°C your piglets will die within minutes.
Older pigs can be in cooler temperatures for short periods without it affecting their health, but they will eat more and produce more waste, which lowers your piggery's food conversion efficiency. Generally, the older your pig, the lower its LCT.
The pig welfare code recommends that you monitor your herds if temperatures fluctuate more than 10°C per day.