Keeping Pigs Cool on Hot Summer Days: the Niman Ranch Way

By Ron Mardesen, 18-year farmer with Niman Ranch, based out of Elliott, Iowa

Every season on the farm presents its own rewards and challenges. Mid to late summer is no exception. Typically, by now the third crop of hay has been cut and county fairs are in full swing. The garden is rewarding us with corn on the cob, fresh tomatoes, ripe watermelon and, of course, new peas.

Along with these rewards, come challenges. Higher temperatures and higher humidity might be good for the crops, but can be uncomfortable for our pigs.

Pigs share a lot of common traits with people. We are both warm blooded (we are mammals), we are both monogastrics (we have one stomach) and we are both omnivores (we can eat almost anything).  

However, how we keep ourselves cool is very different. People can sweat to keep cool. When it gets hot or when we exercise, we sweat to cool down. Pigs don’t have that ability. A pig relies on a slightly different technique to stay cool. They must add moisture to their skin and as the moisture evaporates, heat is pulled from their body. The easiest way for me to describe this is imagine yourself stepping out of a shower (still wet) and standing directly in front of a fan. You are chilled almost immediately.

The warmer temperatures of later summer and the higher humidity can challenge the pig’s ability to remain cool. The temperatures warm them up and the higher humidity slows how fast moisture can evaporate off the skin.

A hot pig is not a happy pig. Unhappy pigs eat less (grow slower), unhappy pigs take their frustrations out on other unhappy pigs (they might nip their neighbor’s tail or ears), unhappy pigs don’t share very well (they will congregate around the waterers to keep cool, preventing other pigs from getting drinks) and if they get hot enough their own health might be in danger.

Perhaps surprisingly, it is much easier to keep a pig warm in the winter than it is to keep them cool in the summer. The Niman Ranch system has pigs on pasture or in open sided barns, which might sound like it might be chilly for the pigs during colder months, but our protocols require clean, dry bedding. In colder weather you keep the pig’s sleeping area dry and well bedded and they will do just fine to keep warm and cozy. In the summer time to keep a pig cool you must work much harder.

How to Keep a Pig Cool in Hot Weather:

• “If it’s too hot, get out of the kitchen.” Well if it’s too hot, get out of the sun. Providing pigs some sort of shade can help keep them cool. A shade tree is awesome. Generally, the temperature under a shade tree will be at least 10 degrees cooler than standing in direct sunlight.
• We have all seen pictures of children playing in the cities in the summer time around fire hydrants that have been turned on. Those hydrants give the children a source of entertainment and a great way to cool off. Spraying pigs with a mister or a garden hose will have the same effect on the pigs that the hydrants have on the children.
• When it’s hot, who doesn’t enjoy a dip in the pool? Well guess what? A pig is no different. When my daughter was small she used to say she loved me “Like pigs love mud puddles” A dip in the pool (or mud puddle) is a great way to cool off.
• After shade and water, airflow becomes critical to helping keep pigs cool. Stepping out of a shower wet will cool you off, but stepping out of the shower in front of a fan will really bring a chill. That increased air flow will help the moisture on the pig’s skin evaporate faster and keep the pig cooler. A gentle summer breeze will go a long way to keep a pig cool. A good strong fan won’t hurt anything either.
• “If Momma ain’t happy, no one is happy!” This is especially true if Momma is a 500 lb sow and she is having her babies. Any farmer who has raised pigs understands how difficult it is to keep Momma comfortable during farrowing. If she is uncomfortable she will have a tendency to get up and down and move around a lot. That could be dangerous for the new born babies. There must be the right mix of air flow to keep her comfortable and not too much to chill the baby piglets.

Soon enough, these hot summer days will end and lead to the hectic schedules of fall and harvest, another farm season behind us.