An Iowa State University (ISU) researcher is studying a possible link between odor and swine rations. Wendy Powers, ISU assistant professor of animal science, recently conducted a feeding trial that studied the effects of bloodmeal in swine rations on manure composition and odor.

Fifteen, 5-week-old pigs were fed experimental rations for each of two, four-week periods. The rations included either 3% bloodmeal, 1.5% bloodmeal or no bloodmeal. The pigs were housed separately depending on their ration, and manure was cleaned from each room once each week.

Manure and air samples were collected twice weekly, for the last three weeks of each feeding period. Manure samples were sent to a commercial laboratory for compositional analyses. Air samples were analyzed by a trained human panel and by an electronic nose, which is a machine designed to measure odors.

Powers says she found a strong trend for increased odor as the amount of bloodmeal was increased in the diets. Odor also increased as the length of time the manure was stored increased from four to six days. No performance differences were found with any of the feeding regimens. Powers plans to repeat the feeding trials and conduct further research into feeding to reduce manure odor.

Researcher: Wendy Powers, Iowa State University, phone: (515) 294-1635.