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| Bartlelt-Hunt, S.L.; De Vivo, S; Johnson, L.C.; Snow, D.D.; Kranz, W.L.; Mader, T.L.; Shapiro, C.A.; Van Donk, S.J.; Shelton, D.P.; Zhang, T.C.; Tarkalson, D.D.. |
| In this study, the fate of steroid hormones in beef cattle manure composting is evaluated. The fate of 16 steroids and metabolites was evaluated in composted manure from beef cattle administered growth promotants and from beef cattle with no steroid hormone implants. The fate of estrogens (primary detected as estrone), androgens, progesterone, and the fusarium metabolite and implant a-zearalanol were monitored in manure compost piles. First-order decay rates were calculated for steroid half-lives in compost and ranged from 8 days for androsterone to 69 days for 4-androsterone. Other steroid concentration data did not fit first-order decay models which may indicate that other microbial processes may result in steroid production or synthesis in... |
| Tipo: Article |
Palavras-chave: Feed preference; Animal; Manure. |
| Ano: 2013 |
URL: http://eprints.nwisrl.ars.usda.gov/1563/1/1519.pdf |
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| Zhang, T.C.; Ma, Rui; Bartelt-Hunt, S.L.; Qi, Yong; Kranz, W.L.; Snow, D.D.; Mader, T.L.; Shapiro, C.A.; Shelton, D.P.; Van Donk, S.J.; Tarkalson, D.D.. |
| In this study, batch sorption and desorption experiments were conducted for testosterone using four agricultural soils and five clay minerals. Significant differences in sorption behavior were observed between abiotic and biotic systems. The Freundlich sorption coefficient Kf (µg per g)/(µg per mL) ranged from 8.53 to 74.46 for soils and from 35.28 to 1243 for clays. The maximum sorption capacity (µg per g) of soils ranged from 25.25 to 440.61 for soils and 168.46 to 499.84 for clays. Correlation of sorption model parameters with soil properties indicated that both clay content and soil organic matter are important variables in predicting testosterone sorption behavior. Observed testosterone desorption from agricultural soils ranged from approximately 14... |
| Tipo: Article |
Palavras-chave: Soil water (soil moisture); Soil; Water. |
| Ano: 2015 |
URL: http://eprints.nwisrl.ars.usda.gov/1606/1/1564.pdf |
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| Van Donk, S.J.; Bigas, S; Kranz, W.L.; Snow, D.D.; Bartlelt-Hunt, S.L.; Mader, T.L.; Shapiro, C.A.; Shelton, D.P.; Tarkalson, D.D.; Zhang, T.C.; Ensley, S.M.. |
| A variety of naturally occurring steroid hormones are regularly excreted by livestock, while additional steroid hormones have been used as growth promoters by the livestock industry. Depending on manure age and storage conditions, both groups of compounds are likely to be present during application to crops. Recent research suggests that some estrogens, androgens and progestagens in surface waters may originate from runoff after land application of livestock manure. Groundwater may also be impacted by livestock manure when used as a nutrient source to crops and may be indicated by excess nitrate in water. Few studies have been conducted to investigate the potential of steroid hormones contamination of groundwater. The objective of this study was to monitor... |
| Tipo: Article |
Palavras-chave: Feed preference; Chemistry; Fertility. |
| Ano: 2013 |
URL: http://eprints.nwisrl.ars.usda.gov/1591/1/1548.pdf |
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