Environmental temperature has big effects on a pig’s health, growth, reproduction and lactation processes. But the animal can tell you a lot about what it’s feeling, provided you learn what to look for and make it a regular practice.

Of course, getting the right temperature is a production issue, but it’s also a well-being issue. The pig can only experience well-being when its environmental temperature is right.

Environmental temperature is one of the more important production factors to be managed on a swine farm. Pigs are often challenged by cool, warm and fluctuating environments. It is important that the environmental temperature be checked several times each day and adjusted as needed.

The ideal temperature differs for pigs, depending on their age, health conditions and feed intake. But in all cases, a pig’s behavior will signal its thermal comfort.

A predictable daily schedule by the caretaker makes it possible for pigs to develop their own daily routines and for the caretaker to become familiar with the pigs’ routines. Once a caretaker becomes familiar with the pigs, he or she can use the messages that the pigs’ activities and body language are sending to determine needed changes in the environmental temperature.

Using the pigs’ behaviors to assess their environmental temperature is a better approach to than using numbers on a thermostat or on a thermometer, especially when they are located at your eye level instead of the pigs’ level. When faced with either cool or warm temperatures a pig makes the quickest and most effective response it can make — it makes a behavioral change. This can be as simple as changing its lying posture, or it can be a complex combination of responses.

Pigs make appropriate changes in posture, location and activity as they try to minimize heat loss (in a cool or cold environment) or to maximize heat loss (in a warm or hot environment). They also will make visible changes associated with other responses to cold or heat stress. 

Here are some behavioral signs that you can use to gauge the nature of the pigs’ environment.

In a comfortable environment pigs will:

  • Lie close to, but barely touch, each other.
  • Perform normal general activity.
  • Produce normal eating activity.
  • Follow normal drinking activity.
  • Have no particularly preferred lying place.

In a cool or cold environment pigs will:

  • Lie on the chest or belly and fold their legs under the body.
  • Huddle (increasing contact with one another).
  • Shiver.
  • Increase feed intake.
  • Decrease their general activity.
  • Avoid cool spots in the environment.
  • Avoid drafty spots in the environment.
  • Seek out any sunny spots in the environment.

In a warm or hot environment pigs will:

  • Lie on their sides, in a sprawled posture.
  • Spread out from one another to decrease contact.
  • Pant or breathe with an open mouth.
  • Lie around and appear lethargic.
  • Decrease general activity.
  • Decrease feed intake.
  • Increase water intake.
  • Increase water play and wallowing.
  • Avoid hot, sunny spots in the room.
  • Seek out drafty spots in the environment.

Finally, during spring and fall seasons, which typically have large outdoor temperature swings and when nighttime temperature is often much cooler than  daytime, it’s important to assess the temperature of the pigs’ environment more frequently than in winter and summer. During transitional seasons, environmental temperature can quickly stray out of the pigs’ comfort zone.

So, sharpen your eyes and let the pigs’ body language tell you if the environmental temperatures are on target.