Objective: To evaluate the effectiveness of altering the pH of manure with sodium bisulfate, thereby decreasing ammonia concentration and fly population in a horse barn environment.
Animals: 4 mixed-breed pony stallions.
Procedure: The 4-week study was scheduled with 2 weeks of treatment (with 2 application rates) and 2 weeks with no treatment (control weeks). During treatment weeks, sodium bisulfate was applied daily to the top of the bedding and straw, then spread on top. Ponies were kept in the stalls 24 hours a day during the 7-day test period and stall cleaning was not done. On day 7 of each week, ammonia concentration, manure pH, number of flies on a fly tape, and fly-evasive behavior patterns were determined.
Results: Sodium bisulfate applied to the horse stall environment daily of either 2.3 or 4.5 kg/9.3 m2 (5 or 10lb/ 100 ft2) decreased ammonia concentration, manure pH, and number of flies in the stall environment, compared with a control period with no sodium bisulfate. Fly-evasive behavior patterns of ponies occupying the stalls, including tail swishes, head tosses, and kicks/strikes, were decreased during the period of sodium bisulfate application.
Conclusion: Sodium bisulfate may be an effective method of decreasing ammonia concentration and may serve as a method of fly control in horse barns.