Give them some air…good air
The recent heavy snows and strong winds in the Midwest have me thinking about barn ventilation. Not in reference to the correct set points and heater offsets, but rather the production, circulation and removal of heat and moisture in the barns. Extreme weather such as snow, wind and ice can wreak havoc on barn ventilation systems. Ventilation of confinement buildings is necessary to regulate temperature, humidity and gases to suppress disease and maintain good air quality. Unfortunately, ventilation also accounts for more than 70 percent of the heat loss from a facility. Additionally, most reports indicate that producers assume ventilation is correct unless temperature fluctuations within the barn are observed. In reality, damp floors, dirty pigs and gas levels are better indicators of inadequate ventilation. Overall, properly ventilated barns will increase profit potential due to efficient heat mitigation and the creation of environmental conditions that promote optimal pig performance. According to the Prairie Swine Centre, 30 percent of all heat loss from a facility occurs through the shell of barn. Barns that aren’t sealed tightly or have poor ventilation designs are more difficult to manage, and they have greater heat loss during cold and windy weather. Many times, we attempt to alleviate these issues by putting plastic over air inlets and/or diverting normal air flow in other ways. Although these solutions may provide short-term relief, they can be self-defeating when it comes to total barn management. Additionally, physical restriction caused by snow and ice affects fan operation and, therefore, air flow through barns. Snow and/or ice can pack into fans and louvers, decreasing air output, allowing cold air to seep in or, worse, preventing the fans from operating at all. Even fans that run constantly are affected by snow and ice accumulation. Impaired ventilation caused by any of these factors can result in costly events. Typically, when ventilation is not right, pigs begin to display different behavior patterns such as changes in their dunging patterns or aggressive behaviors (tail biting, for example). The worst case scenario is varying levels of disease challenges that continue to plague the group of pigs until they are marketed. Winter Barn Management Considerations (with heightened attention during – and even a couple of days after – snow fall or inclement weather)
- Mark all pit fans with flags or sticks to make them easier to find in deep snow.
- Clear all snow from the ground in front of and around all fans to ensure maximum air flow.
- Check air intake/output and fan operation for blockage.
- Cover and insulate staged fans that are not in operation to reduce cold air backdrafts.
- Ensure that fan hoods are secured tightly so high winds do not impede air flow.
- Heaters should be checked daily. Clean relay contact points and the pilot area so they are free of corrosion and make sure fans are working properly to distribute the heated air.
- Heaters should never run when room temperatures are above the set point. The set point is not the desired room temperature; it is the decision point for all devices connected to the controller.
Proper ventilation is essential for optimal pig performance. Understanding heat transfer and the losses that occur through the walls, ceilings and floors will help you combat heat loss during the winter months. Taking additional steps to reduce heat loss through insulation and proper ventilation will further improve energy efficiency and throughput of the buildings. You can access many online resources, including this PorkCast, that provide specific details to determining air flow and speed, set points and pig heat production, etc. Contact your Vita Plus consultant to discussion strategies for your buildings. About the author: Brendan Corrigan is the Vita Plus swine business manager. Originally from Peoria, Ill., Corrigan graduated from the University of Illinois in 2000 with a bachelor’s degree in animal science. He continued on to receive his master’s in swine production and nutrition in 2002. He is a member of the American Society of Animal Science, is recognized as a Professional Animal Scientist, and will earn his master’s of business and science in 2014. Corrigan has 10 years of experience in the swine industry, with extensive research and hands-on experience in nursery, grow-finish, and sow production. He also has a firm understanding of business strategies and economic decisions in pork production. At Vita Plus, Corrigan guides the technical team in product development and nutritional formulation. He also works closely with sales staff to provide service and assist producers with difficult decisions.