Mineralization of hormones in breeder and broiler litters at different water potentials and temperatures

When poultry litter is landspread, steroidal hormones present in the litter may reach surface waters, where they may have undesirable biological effects. In a laboratory study, we determined the mineralization of [4-C-14]-labeled 17 beta-estradiol, estrone, and testosterone in breeder litter at three different water potentials (-56, -24, and -12 MPa) and temperatures (25, 35, and 45 degrees C), and in broiler litter at two different water potentials (-24 and -12 MPa) and temperatures (25 and 35 degrees C). Mineralization was similar in both litters and generally increased with increasing water content and decreasing temperature. After 23 wk at -24 MPa, an average of 27, 11, and < 2% of the radiolabeled testosterone applied to breeder litter was mineralized to (CO2)-C-14 at 25, 35, and 45 degrees C, respectively. In contrast, mineralization of the radiolabeled estradiol and estrone was < 2% after 25 wk at all water potentials, except after 17 wk at 25 degrees C and -12 MPa, where up to 5.9% of the estradiol and 7.8% of the estrone was mineralized. The minimal mineralization suggests that the litters may still be potential sources of hormones to surface and subsurface waters.