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| Registros recuperados: 23 | |
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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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| Niu, M; Appuhamy, J.A.D.R.N; Leytem, A.B.; Dungan, R.S.; Kebreab, Ermias. |
| The study aimed to examine, simultaneously, the effects of changing dietary forage and crude protein (CP) contents on methane (CH4) emissions and nitrogen (N) excretion from lactating dairy cows. Twelve post-peak lactating Holstein cows were randomly assigned to 4 treatments from a 2×2 factorial arrangement of two dietary forage levels [37.4% (LF) vs. 53.3% (HF) of DM] and two dietary CP levels [15.2% (LP) vs. 18.5% (HP) of DM] in a 4×4 Latin square design with four 18 d periods. Alfalfa hay was the sole source of dietary forage. Cows were fed and milked twice daily. During the first 14 d, cows were housed in a free-stall barn, where enteric CH4 emissions were measured using the GreenFeed system from d 8 to 14 in each period. Cows were then moved to... |
| Tipo: Article |
Palavras-chave: Air Emissions; Animal Production; Feed preference; Animal. |
| Ano: 2016 |
URL: http://eprints.nwisrl.ars.usda.gov/1618/1/1575.pdf |
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| Leytem, A.B.; Thacker, P.A.. |
| Intrinsic phytase in swine feeds may alter phytate utilization and solubility of excreted phosphorus. Therefore, the objective of this experiment was to quantify changes in fecal phosphorus composition from swine fed various cereal grains with a range of phytate concentrations and endogenous phytase activities. Twenty-five crossbred barrows weighing 89.3 + or - 6.8 kg were fed one of five diets based on corn, barley, low phytate barley, high fat-low lignin oat or wheat. Experimental diets were formulated to contain 75% of the test grain and were fed for a seven-day acclimation period followed by a three-day fecal collection. Total tract apparent digestibility coefficients were determined for dry matter, phosphorus and phytate using the indicator method.... |
| Tipo: Article |
Palavras-chave: Feed preference; Phosphorous. |
| Ano: 2010 |
URL: http://eprints.nwisrl.ars.usda.gov/1385/1/1360.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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| Silva,A.F.; Cruz,C.; Pitelli,R.L.C.M.; Pitelli,R.A.. |
| This study aimed to evaluate feed preference and control efficacy of grass carp (Ctenopharyngodon idella) on the aquatic macrophytes Ceratophyllum demersum, Egeria densa and Egeria najas. An experiment was carried out at mesocosms conditions with 2,000 liters capacity and water residence time of 2.8 days. C. demersum, E. densa e E. najas biomasses were offered individually with sixty g and coupled in similar quantities of 30 g of each species, evaluated during 81 days, envolving 6 treatments. (1 - C. demersum, 2 - E. najas, 3 -E. densa, 4 - C. demersum + E. najas, 5 - C. demersum + E. densa and 6 - E. najas + E. densa). When offered individually, E. najas and C. demersum presented the same predation rate by grass carp, which was higher than E. densa... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Feed preference; Egeria najas; Ceratophyllum demersum; Egeria densa. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582014000400011 |
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| Registros recuperados: 23 | |
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