Animal Industry Report

Extension Number

ASL R2582



Summary and Implications

Ammonia (NH3), temperature, moisture content, pH, pack depth, nutrient composition and concentration of odorous volatile organic compounds (VOC) were measured at 56 locations in each of four pens in two commercial beef deep-bedded mono-slope facilities (BDMF). Areas of high NH3 concentration occurred randomly throughout the pens. Ammonia concentration increased as pack and ambient air temperature increased. Concentration of VOC was highest in transition areas between the bedded pack and the concrete floor. Depth, moisture content, and pH of the bedded pack did not influence concentration of NH3 and VOC. Nutrient composition of the manure/bedding material in BDMF is similar to manure in open feedlots, except that in BDMF the volatile solids content is much higher. E. coli concentrations can occur at high levels in BDMF and vary with differences in ambient temperature. Priority should be given to NH3 and E. coli mitigation during hot months. However, locationspecific NH3 mitigation will not be effective due to the random distribution of NH3 in the pen. Frequent cleaning of the area surrounding the bedded pack should reduce VOC concentration.

Copyright Holder

Iowa State University