Assessing the benefits of misting-cooling systems for growing/finishing swine as affected by environment and pig placement date

The NCPIG swine growth model was used to evaluate swine growth performance for Wilmington, North Carolina; Bardstown and Mayfield, Kentucky; and Oklahoma City, Oklahoma as influenced by the use of a misting-cooling system. Five pig placement dates (Julian days 106, 126, 146, 166, and 186) were evaluated for each location using 22 years of weather data (1978-1999). The use of a misting system, while quite variable, was found to be generally profitable, reducing the length of the time to reach market weight. As the placement date increased, the average return to misting ($/pig/year) decreased from $8.12 to $1.98 for Oklahoma City, from $6.00 to $1.16 for Wilmington, from $4.14 to $0.99 for Mayfield, and from $3.07 to $0.87 for Bardstown. Based on the prorated value of $1.39 per pig/per year for the cost of a misting system, probabilities for recovering the initial investment amount were determined for each pig placement date and location. These probabilities decreased as the pig placement date increased, except for Oklahoma City, which remained above 98% regardless of the date. For the locations other than Oklahoma City, the probabilities indicated that the earlier placement dates were more favorable for recovering the initial investment.