Dissipation of 17β‐Estradiol in Composted Poultry Litter

The excreted estrogen rate of all livestock in the United States is estimated at 134 kg d−1. The influence of manure treatment on the fate of estrogens is critical in deciding the recycling of over 300 million dry tons of livestock produced annually. The effects of two common manure management practices, heated composting and ambient temperature decomposition, on the fate of 17β‐estradiol in poultry litter were determined. A mixture of poultry litter, wood chips, and straw was amended with [14C]17β‐estradiol and allowed to undergo decomposition with a laboratory‐scale heated composter (HC) or room temperature incubation (RTI) for 24 d. Radiolabel in the finished products was fractionated into water‐extractable, acetone‐extractable, nonextractable, and mineralized fractions. Total 17β‐estradiol radioactive residues in the HC and RTI (n = 2) treatments were not different (P > 0.05), except that statistically less 17β‐estradiol was mineralized to 14CO2 during HC than RTI (1.1 vs. 10.0% for HC and RTI, respectively). Estrone was the major degradation product in extracts of HC and RTI treatments as determined by liquid chromatography/mass spectrometry analyses. The nonextractable residues indicated no quantitative differences among the humins between the treatments. An estimated 3% of the fortified estrogenicity remained after HC treatment, and 15% of the fortified estrogenicity remained after RTI treatment. If reduction of water‐removable, biologically active 17β‐estradiol is the treatment goal, then HC treatment would be slightly preferred over ambient temperature degradation. However, unmanaged, ambient temperature litter piles are less costly and time consuming for food animal producers and result in greater mineralization and similar immobilization of estradiol.