University of Missouri expands HotHog app to protect pigs from heat stress across production stages

Researchers at the University of Missouri are enhancing the HotHog app, funded by a $1.15 million USDA grant, to provide real-time heat stress warnings for various pig breeds, aiming to improve animal health and productivity worldwide.

Researchers at the University of Missouri are extending HotHog, a mobile app designed to warn pork producers when environmental conditions are likely to put pigs at risk of heat stress before the animals show obvious clinical signs. The project has received a $1.15 million grant from the US Department of Agriculture and will broaden the model beyond sows to include recently weaned pigs, growing animals and those close to slaughter weight.

Jay Johnson, an associate professor in Missouri’s College of Agriculture, Food and Natural Resources, developed the app, which launched in 2023 and is already used by more than 2,000 people in over 50 countries. According to the app listings on Apple and Google platforms, it provides hourly and daily predictions of thermal comfort and stress in sows using location-specific forecasts and thermal index categories.

For veterinarians, the biological rationale is straightforward: pigs do not sweat effectively, so rising temperature and humidity can quickly overwhelm their cooling capacity. Heat stress can reduce feed intake, impair growth and reproduction, alter respiration and, in severe cases, contribute to death. Recent reviews and meta-analyses have also linked heat exposure with poorer feed efficiency, higher respiratory rates and elevated rectal temperature.

The Missouri team will use controlled studies at the Animal Science Research Centre and a new thermocline facility at South Farm to record behaviour, activity, water use and posture under defined conditions. The aim is to refine alerts so they are more specific to each production class.

Johnson’s group will also work with Purdue University, the University of Pretoria and the University of Melbourne, while University of Missouri Extension will help train producers and gather feedback.

Image Source: University of Missouri