Hog producers can turn down the heat to save money after weaning pigs

Columbia, Mo. – What do you get when you put hundreds of baby pigs in a building in winter? A big heating bill.

University of Missouri researchers recently turned an eye to reducing energy bills and the carbon footprint caused by heating pig nurseries.

Their research lowered nursery temperatures by 15 degrees at night to reduce heating fuel costs nearly 30 percent and electricity costs 19 percent in the 5-week nursery period. At these temperatures, pigs grew at the same rate as pigs housed under normal nursery management conditions and did not show any problems with illness at these lower nighttime temperatures.

“We wean at a pretty young age where pigs weigh 10-12 pounds, and all the engineering and environmental guides say those pigs need close to 90-degree temperatures,” said Marcia Shannon, an MU Extension state swine specialist. “This study reduced the BTUs used per pig by 29 or 30 percent, post-weaning, and we didn’t see any difference in animal performance or health.”

Unlike other inputs, hog producers have no control over the price of propane, natural gas or heating oil used to heat their hog barns. Soaring prices can eat away at profits, like when propane reached a record of $1.86 per gallon in 2008. Today’s price compares at $1.47 per gallon, according to the U.S. Energy Information Administration.

Shannon joined researchers from four other universities – the University of Minnesota, Ohio State University and South Dakota State University – to test lower nocturnal temperatures in several temperate zones. While heating costs were higher in northern states, all locations showed the same percentage of savings.

“It costs approximately $1.50 – $2 to heat each pig in the nursery stage, and we reduced that cost by about 60 cents-per-pig,” Shannon said. “In the grand scheme of things, those savings might not seem like a lot, but that’s $600 for every 1,000 pigs during the nursery stage.”

This study piggybacks on research from 2007 that lowered temperatures 10 degrees from 7 p.m. to 7 a.m. seven days after weaning piglets. That research showed a 14 percent drop in heating costs and 11 percent reduction in electricity use. Those results begged the question, how much more could producers save in heating costs?

“We decided to see how far we could push that,” Shannon said. “We dropped temperatures 15 degrees, starting five days, post-weaning.”

Each university conducted two separate tests in winter months between Dec. 2009 and March 2011. Nursery sizes ranged from 50 to 360 pigs, with each university simultaneously raising a group of pigs at regular temperatures and reduced nocturnal temperatures.

MU studied 90 pigs at temperatures reduced to 71 degrees at night (7 p.m. to 7 a.m.) and compared it to an equal size control group nursery with temperatures set at 86 degrees at night. Each week temperatures were also reduced 3.5 degrees for both normal and reduced temperature groups, a standard practice in normal nursery situations.

Lower temperatures might not have always worked for producers, but newer genetics have changed temperature needs. Now producers raise leaner, faster-growing pigs that have more energy and produce more heat.

“We’re looking at a different type of pig today with a higher rate of heat production than we had back in the late 1980s or early 1990s,” Shannon said. “After the first 14 days in the nursery, we couldn’t get a 15-degree drop at night because the pigs were large enough that they created enough body heat in the buildings.”

Find more about MU swine research at http://agebb.missouri.edu/commag/swine.