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| 11. |  | VELAZCO, J.I.; BREMNER, G.; LI, L.; LUIJBEN, K.; HEGARTY, R.S.; PERDOK, H. Short-term emission measurements in beef feedlot cattle to demonstrate enteric methane mitigation from dietary nitrate.[Poster]. In: Greenhouse Gas and Animal Agriculture (GGAA) scientific conference, (5º, Dublin, Irlanda), 23-26 Jun. 2013.| Biblioteca(s): INIA Treinta y Tres. |
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| 16. | | DE BARBIERI, I.; HEGARTY, R.S.; ODDY, V.H.; LI, L.; BLAKELY, A.; VELAZCO, J.; DONALDSON, A.; OSBORNE, E. Association of wool growth with rumen function in sheep. [Poster]. In: Recent Advances in Animal Nutrition, Australia conference, Environmental and Rural Science, University of New England, Armidale, Australia, 2013.| Biblioteca(s): INIA Tacuarembó. |
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| 17. | | DE BARBIERI, I.; HEGARTY, R.S.; ODDY, V.H.; LI, L.; BLAKELY, A.; VELAZCO, J.I.; DONALDSON, A.; OSBORNE, E. Association of wool growth with rumen function in sheep. [Resumen]. In: Recent Advances in Animal Nutrition-Australia, 2013. Poster Abstracts. Animal Science, School of Environmental and Rural Science. University of New England, Armidale, Australia, 2013. p. 21-22| Biblioteca(s): INIA Tacuarembó. |
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| 18. | | DE BARBIERI, I.; ODDY, V.H.; HEGARTY, R.S.; LI, L.; HAYNES, F.E.M.; BLAKELY, A. Evaluation of computed tomography for estimating reticulo-rumen characteristics. [Poster]. In: Recent Advances in Animal Nutrition, Australia conference, Environmental and Rural Science, University of New England, Armidale, Australia, 2013.| Biblioteca(s): INIA Tacuarembó. |
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| 19. | | DE BARBIERI, I.; HEGARTY, R.S.; ODDY, V.H.; BARNETT, M.C.; LI, L.; NOLAN, J.V. Sheep of divergent genetic merit for wool growth do not differ in digesta kinetics while on restricted intakes. Animal Production Science, May 2014, v. 54, no. 9, p. 1243-1247. DOI: https://doi.org/10.1071/AN14319 Received 12 March 2014; accepted 12 May 2014; published online 10 July 2014. Acknowledgements: The authors thank Evelyn Osborne, Jose Velazco, Alistair Donaldson, Carolina Silveira, Gary Cluley, Leanne Lisle, Sue Mortimer and Andrew...| Biblioteca(s): INIA Tacuarembó. |
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| 20. | | HERD, R.M.; ARTHUR, P.F.; HEGARTY, R.S.; BIRD-GARDINER, T.; DONOGHUE, K.A.; VELAZCO, J.I. Predicting metabolisable energy intake by free-ranging cattle using multiple short-term breath samples and applied to a pasture case-study. (Article in Press) Animal Production Science, 4 Nov. 2020, 61(4), p. 381-389 Doi: https://doi.org/10.1071/AN20162 Article history: Received 3 April 2020, accepted 11 October 2020, published online 4 November 2020.| Biblioteca(s): INIA Treinta y Tres. |
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| Registros recuperados : 24 | |
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 | Acceso al texto completo restringido a Biblioteca INIA Treinta y Tres. Por información adicional contacte bibliott@inia.org.uy. |
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Registro completo
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Biblioteca (s) : |
INIA Treinta y Tres. |
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Fecha actual : |
24/11/2015 |
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Actualizado : |
24/06/2021 |
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Tipo de producción científica : |
Artículos en Revistas Indexadas Internacionales |
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Circulación / Nivel : |
Internacional - A |
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Autor : |
COTTLE, D.J.; VELAZCO, J.I.; HEGARTY, R.S.; MAYER, D.G. |
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Afiliación : |
JOSÉ IGNACIO VELAZCO DE LOS REYES, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay. |
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Título : |
Estimating daily methane production in individual cattle with irregular feed intake patterns from short-term methane emission measurements. |
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Fecha de publicación : |
2015 |
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Fuente / Imprenta : |
Animal, 2015, v. 9 (12), p. 1949-1957. |
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DOI : |
10.1017/S1751731115001676 |
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Idioma : |
Inglés |
|
Notas : |
Article history: Received 19 March 2015; Accepted 17 July 2015; First published online 24 August 2015. |
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Contenido : |
Spot measurements of methane emission rate (n = 18 700) by 24 Angus steers fed mixed rations from GrowSafe feeders were made over 3- to 6-min periods by a reenFeed emission monitoring (GEM) unit. The data were analysed to estimate daily methane production (DMP; g/day) and derived methane yield (MY; g/kg dry matter intake (DMI)). A one-compartment dose model of spot emission rate v. time since the preceding meal was compared with the models of Wood (1967) and Dijkstra et al. (1997) and the average of spot measures. Fitted values for DMP were calculated from the area under the curves. Two methods of relating methane and feed intakes were then studied: the classical calculation of MY as DMP/DMI (kg/day); and a novel method of estimating DMP from time and size of preceding meals using either the data for only the two meals preceding a spot measurement, or all meals for 3 days prior. Two approaches were also used to estimate DMP from spot measurements: fitting of
splines on a ?per-animal per-day? basis and an alternate approach of modelling DMP after each feed event by least squares (using Solver), summing (for each animal) the contributions from each feed event by best-fitting a one-compartment model. Time since the preceding meal was of limited value in estimating DMP. Even when the meal sizes and time intervals between a spot measurement and all feeding events in the previous 72 h were assessed, only 16.9% of the variance in spot emission rate
measured by GEM was explained by this feeding information. While using the preceding meal alone gave a biased (underestimate) of DMP, allowing for a longer feed history removed this bias. A power analysis taking into account the sources of variation in DMP indicated that to obtain an estimate of DMP with a 95% confidence interval within 5% of the observed 64 days mean of spot measures would require 40 animals measured over 45 days (two spot measurements per day) or 30 animals measured over 55 days. These numbers suggest that spot measurements could be made in association with feed efficiency tests made over 70 days. Spot measurements of enteric emissions can be used to define DMP but the number of animals and samples are larger than are needed when day-long measures are made. MenosSpot measurements of methane emission rate (n = 18 700) by 24 Angus steers fed mixed rations from GrowSafe feeders were made over 3- to 6-min periods by a reenFeed emission monitoring (GEM) unit. The data were analysed to estimate daily methane production (DMP; g/day) and derived methane yield (MY; g/kg dry matter intake (DMI)). A one-compartment dose model of spot emission rate v. time since the preceding meal was compared with the models of Wood (1967) and Dijkstra et al. (1997) and the average of spot measures. Fitted values for DMP were calculated from the area under the curves. Two methods of relating methane and feed intakes were then studied: the classical calculation of MY as DMP/DMI (kg/day); and a novel method of estimating DMP from time and size of preceding meals using either the data for only the two meals preceding a spot measurement, or all meals for 3 days prior. Two approaches were also used to estimate DMP from spot measurements: fitting of
splines on a ?per-animal per-day? basis and an alternate approach of modelling DMP after each feed event by least squares (using Solver), summing (for each animal) the contributions from each feed event by best-fitting a one-compartment model. Time since the preceding meal was of limited value in estimating DMP. Even when the meal sizes and time intervals between a spot measurement and all feeding events in the previous 72 h were assessed, only 16.9% of the variance in spot emission rate
measured by GEM was explained by ... Presentar Todo |
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Palabras claves : |
GASES DE EFECTO INVERNADERO; GREENFEED; MODELS; SPLINES. |
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Thesagro : |
METANO; MODELOS ANIMALES; VACUNOS. |
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Asunto categoría : |
-- |
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Marc : |
LEADER 03126naa a2200265 a 4500
001 1053984
005 2021-06-24
008 2015 bl uuuu u00u1 u #d
024 7 $a10.1017/S1751731115001676$2DOI
100 1 $aCOTTLE, D.J.
245 $aEstimating daily methane production in individual cattle with irregular feed intake patterns from short-term methane emission measurements.$h[electronic resource]
260 $c2015
500 $aArticle history: Received 19 March 2015; Accepted 17 July 2015; First published online 24 August 2015.
520 $aSpot measurements of methane emission rate (n = 18 700) by 24 Angus steers fed mixed rations from GrowSafe feeders were made over 3- to 6-min periods by a reenFeed emission monitoring (GEM) unit. The data were analysed to estimate daily methane production (DMP; g/day) and derived methane yield (MY; g/kg dry matter intake (DMI)). A one-compartment dose model of spot emission rate v. time since the preceding meal was compared with the models of Wood (1967) and Dijkstra et al. (1997) and the average of spot measures. Fitted values for DMP were calculated from the area under the curves. Two methods of relating methane and feed intakes were then studied: the classical calculation of MY as DMP/DMI (kg/day); and a novel method of estimating DMP from time and size of preceding meals using either the data for only the two meals preceding a spot measurement, or all meals for 3 days prior. Two approaches were also used to estimate DMP from spot measurements: fitting of splines on a ?per-animal per-day? basis and an alternate approach of modelling DMP after each feed event by least squares (using Solver), summing (for each animal) the contributions from each feed event by best-fitting a one-compartment model. Time since the preceding meal was of limited value in estimating DMP. Even when the meal sizes and time intervals between a spot measurement and all feeding events in the previous 72 h were assessed, only 16.9% of the variance in spot emission rate measured by GEM was explained by this feeding information. While using the preceding meal alone gave a biased (underestimate) of DMP, allowing for a longer feed history removed this bias. A power analysis taking into account the sources of variation in DMP indicated that to obtain an estimate of DMP with a 95% confidence interval within 5% of the observed 64 days mean of spot measures would require 40 animals measured over 45 days (two spot measurements per day) or 30 animals measured over 55 days. These numbers suggest that spot measurements could be made in association with feed efficiency tests made over 70 days. Spot measurements of enteric emissions can be used to define DMP but the number of animals and samples are larger than are needed when day-long measures are made.
650 $aMETANO
650 $aMODELOS ANIMALES
650 $aVACUNOS
653 $aGASES DE EFECTO INVERNADERO
653 $aGREENFEED
653 $aMODELS
653 $aSPLINES
700 1 $aVELAZCO, J.I.
700 1 $aHEGARTY, R.S.
700 1 $aMAYER, D.G.
773 $tAnimal, 2015$gv. 9 (12), p. 1949-1957.
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