Hot Climate Temperature and Moisture Variations in Tunnel and Naturally Ventilated Pig Gestations Buildings

Larry Jacobson, Professor
Carlos Pijoan, Professor, Clinical and Population Sciences, College of Veterinary Medicine
Verlyn Johnson, Information Technology Professional

Funding Source

Minnesota Agricultural Experiment Station

Objective

The objective of the research project is to determine temperature and moisture variation in tunnel and naturally ventilated pig gestation facilities in Sonora, Mexico.

Need or Impact

The fundamental need of a ventilation system in an animal building is for the removal and control of animal heat and moisture production. Measuring the dry-bulb and dew-point temperatures and their distribution in the building is a good measure of the effectiveness of the ventilation systems in a livestock or poultry barn. For pig buildings, ambient barn temperature is one of the most important factors that affect animal or pig performance. Numerous studies have shown a negative pig performance with high barn temperatures for growing pigs and for lactating sows. In addition, large diurnal variations in barn temperatures also affected the performance of growing pigs, especially during warm or hot conditions.

Project Status

During a one-year monitoring period (February 2002 to January 2004), large temperature and moisture variations were found within and between four adjacent 600+ sow gestation barns (300+ ft long by 36 ft wide) that were located in the hot dry climate of Sonora, Mexico. Two of the barns had tunnel mechanical ventilation systems while the other two were naturally ventilated. Even with these variations, sow performance, as measured by farrowing rate and litter size, was essentially unaffected. Reasons for these large temperature and moisture conditions included large ambient (outside) temperature swings both diurnally and seasonally, use of the tunnel mechanical ventilation system during the wintertime, and the lack of adequate inlet controls for the naturally ventilated systems resulting in under ventilation (high moisture levels) during nighttime conditions.