RHA™ Anti-Trenbolone monoclonal antibody, clone TB

Trenbolone acetate metabolites are endocrine-active contaminants discharged into the aquatic environment in runoff from agricultural fields, rangelands, and concentrated animal feeding operations. To investigate the environmental fate of these compounds and their biotransformation mechanisms, the authors used inocula from a variety of different water sources and dosed biologically active microcosms with approximately 1400 ng/L of trenbolone acetate metabolites, including 17-trenbolone, trendione, and 17-trenbolone. To investigate aerobic biotransformation rates and interconversions between known trenbolone acetate metabolites, gas chromatography-tandem mass spectrometry was used to measure concentrations and assess product distributions as a function of time. High-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to characterize novel transformation products and potential transformation pathways. Kinetic analysis yields observed half-lives of approximately 0.9 d, 1.3 d, and 2.2 d for 17-trenbolone, trendione, and 17-trenbolone, respectively, at 20 degrees C, although colder conditions increased half-lives to 8.5 d and biphasic transformation was observed. Relative to reported faster attenuation rates in soils, trenbolone acetate metabolites are likely more persistent in aqueous systems. Product distributions indicate an enzymatic preference for biotransformation between trendione and 17-trenbolone. The LC-MS/MS characterization indicates dehydrogenation products as the major detectable products and demonstrates that major structural elements responsible for bioactivity in steroids are likely retained during biotransformation. Environ Toxicol Chem 2015;34:1472-1484. (c) 2015 SETAC

Commercial implants can have different coating technologies, carriers, and hormone amounts that result in different payout characteristics and effects on cattle growth. Therefore, the objective of this study was to evaluate 2 implants in stocker steers on a 90-d grazing season. Implants were Revalor-G (REV), which contains 40 mg of trenbolone acetate and 8 mg of estradiol, is uncoated, and has a cholesterol carrier, or Synovex One Grass (SYN), which contains 150 mg of trenbolone acetate and 21 mg of estradiol benzoate and has a porous polymer coating. Steers (n = 242) were weighed with an overnight shrink on d 0, 44, and 91. Steers were implanted on d 0 and assigned to 1 of 7 pastures in a completely randomized complete block design with pasture as block. Total gains and gains in each half of the grazing season were evaluated. Average daily gain was not different based on implant type (P = 0.35; 1.16 kg/d for REV and 1.13 kg/d for SYN; SEM = 0.02) nor was total BW gain (P = 0.65; 101 kg for REV vs. 100 kg for SYN; SEM = 2.3). Additionally, BW gain and ADG were not different between implants in both sections of the grazing period (P >= 0.45). Overall, cattle performance was not different regardless of hormone amount and coating technology in implants in a short-duration grazing period with stocker steers, and these data do not support a price premium for SYN over REV in this grazing system.