Characterization of trenbolone acetate and estradiol metabolite excretion profiles in implanted steers
- 22 September 2014
- journal article
- research article
- Published by Wiley in Environmental Toxicology and Chemistry
- Vol. 33 (12), 2850-2858
- https://doi.org/10.1002/etc.2757
Abstract
Exogenous growth promoters have been used in US beef cattle production for over 50 yr. The environmental fate and transport of steroid growth promoters suggest potential for endocrine‐disrupting effects among ecological receptors; however, the initial excretion of steroid metabolites from cattle administered growth promoters has not been well characterized. To better characterize excretion of trenbolone acetate and estrogen metabolites, steers were assigned to 1 of the following treatment groups: control, given no implant, or treatment, administered a combination implant (200 mg trenbolone acetate, 40 mg estradiol). Blood, urine, and fecal samples were collected over the course of 112 d following implantation. Samples were extracted and analyzed by liquid chromatography tandem mass spectrometry for trenbolone acetate and estrogen metabolites. In both urine and feces, 17α‐trenbolone and 17α‐estradiol were the predominant metabolites following implantation. Mean concentrations of 17α‐trenbolone and 17α‐estradiol in feces of implanted steers were 5.9 ± 0.37 ng/g and 2.7 ± 0.22 ng/g, respectively. A best‐fit model is presented to predict 17α‐trenbolone and 17α‐estradiol excretion from steers receiving implants. The present study provides the first characterization of both trenbolone and estrogen metabolites in excreta from implanted cattle and will help provide estimates of steroid production from feedyards in the United States. Environ Toxicol Chem 2014;33:2850–2858. © 2014 SETACKeywords
Funding Information
- US Department of Agriculture National Institute of Food and Agriculture (2010-85112-20573)
This publication has 46 references indexed in Scilit:
- Occurrence of Trenbolone Acetate Metabolites in Simulated Confined Animal Feeding Operation (CAFO) RunoffEnvironmental Science & Technology, 2012
- Concentrations of Free and Conjugated Estrogens at Different Landscape Positions in an Agricultural Watershed Receiving Poultry LitterWater, Air, & Soil Pollution, 2012
- Effect of Growth Promotants on the Occurrence of Endogenous and Synthetic Steroid Hormones on Feedlot Soils and in Runoff from Beef Cattle Feeding OperationsEnvironmental Science & Technology, 2012
- Fate of Endogenous Steroid Hormones in Steer Feedlots Under Simulated Rainfall-Induced RunoffEnvironmental Science & Technology, 2011
- Free and Conjugated Estrogen Exports in Surface‐Runoff from Poultry Litter–Amended SoilJournal of Environmental Quality, 2010
- High estrogen concentrations in receiving river discharge from a concentrated livestock feedlotScience of The Total Environment, 2010
- Rangeland Grazing as a Source of Steroid Hormones to Surface WatersEnvironmental Science & Technology, 2007
- Identification of Metabolites of Trenbolone Acetate in Androgenic Runoff from a Beef FeedlotEnvironmental Health Perspectives, 2006
- Dairy Wastewater, Aquaculture, and Spawning Fish as Sources of Steroid Hormones in the Aquatic EnvironmentEnvironmental Science & Technology, 2004
- Hormone containing growth promoting implants in farmed livestockAdvanced Drug Delivery Reviews, 1999