Environment, respiratory disease, and performance of pigs in three Saskatchewan grower-finisher barns.

A microcomputer-based environmental monitoring system was used to monitor temperature, humidity, and ventilation rate continuously in three commercial grower-finisher swine barns in Saskatchewan. During the monitoring period, a group of pigs in each barn was examined for growth rate, amount of lung affected with pneumonia, and degree of atrophic rhinitis. In addition, the total bacterial colony forming particle count within the airspace of each barn was measured once each week.Significant differences existed among barns for daily maximum and minimum temperature, relative humidity, ventilation rate, and average bacterial colony forming particle counts. There was no difference among farms in the average percentage of lung affected with pneumonia, average snout atrophy score, or growth rate of the test animals.On one farm, there was a significant positive correlation between snout score and percentage of lung affected with pneumonia. On another farm, there was a significant negative correlation between percentage of lung affected with pneumonia and growth rate.