High

Hog barns typically aren't the nicest places to be at the best of times, but try living in one during a heat wave. Scientists at Indiana's Purdue University have developed a self-activating hog-cooling pad for just such situations.

First and foremost, it's important to keep hogs from overheating simply for the welfare of the animals. That said, there are additional benefits to keeping them cool.

"Under heat stress conditions, lactating sows reduce their feed intake and milk output to attempt to reduce their metabolic heat production. In consequence, their piglet growth and subsequent reproductive performance is negatively affected," said Francisco Cabezon of Minnesota's Pipestone Research, which trialed the pads. "In boars, some negative impacts of heat stress are decreased sperm motility and concentration and an increase in sperm abnormalities."

Designed by Purdue's professors Allan Schinckel and Robert M. Stwalley III, the pads each consist of a rubber base and a 2 x 4-foot (610 x 1,219-mm) aluminum tread plate, between which are sandwiched a network of copper piping and temperature sensors.

If the sensors detect that a hog lying on the pad is too hot, they trigger a connected pump to circulate cold water through the pipes, flushing out the warm water already in them. These flushings continue every few minutes, brining the hog's body temperature back down to normal. Depending on the setup, the flushed warm water can be chilled and reused.

In initial tests performed on hogs at the university, the technology definitely showed promise.

"We saw a decrease in their overall respiration rates, slightly lower internal temperatures and lower daily maximum temperatures," said Schinckel. "The sows also produced more heat, which corresponded to an increase in their feed intake and milk production; this improves animal welfare and well-being. Piglets who were on the cooling pads had a 26% increase in weaning weight and 7.2% increase in feed intake."

The technology has been licensed to Canada's IHT Group, which plans to bring a product to the North American market next spring. Improvements to the commercial model may include less expensive, better-performing stainless steel piping.

Source: Purdue University