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Registro Completo |
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Biblioteca(s): |
Embrapa Pecuária Sul. |
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Data corrente: |
28/11/2011 |
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Data da última atualização: |
15/02/2012 |
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Tipo da produção científica: |
Resumo em Anais de Congresso |
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Autoria: |
LACA, E. A.; GENRO, T. C. M.; GENRO NETO, J. S. |
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Afiliação: |
EMILIO ANDRÉS LACA, University of California Davis, CA, USA; TERESA CRISTINA MORAES GENRO, CPPSUL; JAIRO SILVEIRA GENRO NETO, Universidade Federal de Santa Maria, RS, Brasil. |
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Título: |
Bayesian hierarchical models to improve estimation of diet composition by alkane profiles. |
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Ano de publicação: |
2011 |
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Fonte/Imprenta: |
In: REUNIÓN DE LA ASOCIACIÓN LATINOAMERICANA DE PRODUCCIÓN ANIMAL, 22., 2011, Montevideo, Uruguay. Memorias... Montevideo: Asociación Uruguaya de Producción Animal, 2011. |
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Descrição Física: |
1 CD-ROM. |
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Idioma: |
Inglês |
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Conteúdo: |
Alkane profiles in forage and feces are used to determine diet composition, essentially by inverting a linear mixing equation. Depending on the number of dietary components, number of alkanes and difference in forage profiles, the linear equations can be over or underdetermined. We compared the typical non-negative least squares (NNLS) method against a novel Bayesian hierarchical model (BHM) where diet composition is represented as latent variables modeled with parameters shared by the models for fecal and forage profiles. Forage and fecal profiles were obtained from steers grazing either Brachiaria brizantha cv Marandu, Panicum maximum cv. Mombaça, or Pennisetum purpureum cv. Cameroon at Embrapa Beef Cattle, Campo Grande, MS, Brazil. Herbage and fecal samples were collected in the dry and early wet seasons. Herbage was sampled by 20-cm horizons sorted into stem/sheath and leaf blade as dietary components. Feces were collected from 6 animals in the morning and afternoon. Fecal profiles were corrected by faecal recoveries using mean values from the literature. Distributions of diets estimated by NNLS were obtained by Monte Carlo simulation of profiles using parameters and covariance matrices estimated from data. The BHM yielded posterior distributions directly by using Monte Carlo Markov Chains. NNLS resulted in highly variables diets with distributions that were clearly non-normal. BHM resulted in quasi-normal posterior distributions. We conclude that both approaches are better than the normal approach where diet covariances are calculated ad-hoc. The BHM method has the potential to be vastly superior because it allows the simultaneous integration in a formally correct manner, however, convergence can be difficult. MenosAlkane profiles in forage and feces are used to determine diet composition, essentially by inverting a linear mixing equation. Depending on the number of dietary components, number of alkanes and difference in forage profiles, the linear equations can be over or underdetermined. We compared the typical non-negative least squares (NNLS) method against a novel Bayesian hierarchical model (BHM) where diet composition is represented as latent variables modeled with parameters shared by the models for fecal and forage profiles. Forage and fecal profiles were obtained from steers grazing either Brachiaria brizantha cv Marandu, Panicum maximum cv. Mombaça, or Pennisetum purpureum cv. Cameroon at Embrapa Beef Cattle, Campo Grande, MS, Brazil. Herbage and fecal samples were collected in the dry and early wet seasons. Herbage was sampled by 20-cm horizons sorted into stem/sheath and leaf blade as dietary components. Feces were collected from 6 animals in the morning and afternoon. Fecal profiles were corrected by faecal recoveries using mean values from the literature. Distributions of diets estimated by NNLS were obtained by Monte Carlo simulation of profiles using parameters and covariance matrices estimated from data. The BHM yielded posterior distributions directly by using Monte Carlo Markov Chains. NNLS resulted in highly variables diets with distributions that were clearly non-normal. BHM resulted in quasi-normal posterior distributions. We conclude that both approaches are bet... Mostrar Tudo |
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Palavras-Chave: |
Melhoramento forrageira; Modelo bayesiano; Perfil alcalino. |
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Categoria do assunto: |
K Ciência Florestal e Produtos de Origem Vegetal |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/48108/1/G158-pagina173poster.pdf
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Marc: |
LEADER 02430nam a2200181 a 4500
001 1907473
005 2012-02-15
008 2011 bl uuuu u00u1 u #d
100 1 $aLACA, E. A.
245 $aBayesian hierarchical models to improve estimation of diet composition by alkane profiles.$h[electronic resource]
260 $aIn: REUNIÓN DE LA ASOCIACIÓN LATINOAMERICANA DE PRODUCCIÓN ANIMAL, 22., 2011, Montevideo, Uruguay. Memorias... Montevideo: Asociación Uruguaya de Producción Animal$c2011
300 $c1 CD-ROM.
520 $aAlkane profiles in forage and feces are used to determine diet composition, essentially by inverting a linear mixing equation. Depending on the number of dietary components, number of alkanes and difference in forage profiles, the linear equations can be over or underdetermined. We compared the typical non-negative least squares (NNLS) method against a novel Bayesian hierarchical model (BHM) where diet composition is represented as latent variables modeled with parameters shared by the models for fecal and forage profiles. Forage and fecal profiles were obtained from steers grazing either Brachiaria brizantha cv Marandu, Panicum maximum cv. Mombaça, or Pennisetum purpureum cv. Cameroon at Embrapa Beef Cattle, Campo Grande, MS, Brazil. Herbage and fecal samples were collected in the dry and early wet seasons. Herbage was sampled by 20-cm horizons sorted into stem/sheath and leaf blade as dietary components. Feces were collected from 6 animals in the morning and afternoon. Fecal profiles were corrected by faecal recoveries using mean values from the literature. Distributions of diets estimated by NNLS were obtained by Monte Carlo simulation of profiles using parameters and covariance matrices estimated from data. The BHM yielded posterior distributions directly by using Monte Carlo Markov Chains. NNLS resulted in highly variables diets with distributions that were clearly non-normal. BHM resulted in quasi-normal posterior distributions. We conclude that both approaches are better than the normal approach where diet covariances are calculated ad-hoc. The BHM method has the potential to be vastly superior because it allows the simultaneous integration in a formally correct manner, however, convergence can be difficult.
653 $aMelhoramento forrageira
653 $aModelo bayesiano
653 $aPerfil alcalino
700 1 $aGENRO, T. C. M.
700 1 $aGENRO NETO, J. S.
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Registro original: |
Embrapa Pecuária Sul (CPPSUL) |
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| Registros recuperados : 14 | |
| 3. |  | LACA, E.; GENRO, T. C. M.; BREMM, C.; GENRO, J.; SCHRIEFER, C. Patch size controls selectivity of sheep grazing grass-clover grasslands. In: ANNUAL MEETING OF THE SOCIETY FOR RANGE MANAGEMENT, 64., 2011, Billings, MT. Abstracts... [Wheat Ridge: Society for Range Management], 2011. p. 392.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| 5. | | SCARLATO, S.; CARRIQUIRY, M.; CARMO, M. do; FABER, A.; GENRO, T. C. M.; LACA, E.; SOCA, P. Foraging behavior of beef cows grazing native grassland: effect of herbage allowance on temporal and spatial grazing patterns. In: JOINT ANNUAL MEETING, 2012, Phoenix. [Abstracts...]. Phoenix: ADSA: ASAS, 2012. Publicado em: Journal of Animal Science, v. 90, p. 502, Supplement 3; Dairy Science, v. 95, Supplement 2.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| 6. | | GENRO, T. C. M.; GARCIA, E. N.; BONILHA, C. L.; ÁVILA, M. R.; FEDRIGO, J. K.; LACA, E. A. Grazing site selection by heifers in improved Pampa grasslands. In: INTERNATIONAL RANGELAND CONGRESS, 9., 2011, Rosario, Argentina. Diverse rangelands for a sustainable society: [proceedings...]. Rosario: Instituto Nacional de Tecnología Agrpecuaria; Asociación Argentina para el Manejo de Pastizales Naturales, 2011. p. 667.| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| 7. | | BRATZ, M. M.; GENRO, T. C. M.; FARIA, B. M de; LACA, E. A.; SISTI, R. N.; CHAVES, D. C. Comportamento ingestivo de bovinos de corte em pastagem natural com diferentes níveis de intensificação. In: SIMPÓSIO DE INICIAÇÃO CIENTÍFICA DA EMBRAPA PECUÁRIA SUL, 6., 2016, Bagé. Resumos... Bagé: Embrapa Pecuária Sul, 2016. p. 21. Claudia Cristina Gulias Gomes, editora técnica.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| 8. | | FARIA, B. M. de; GENRO, T. C. M.; ROSSETTO, J.; PRATES, E. R.; SISTI, R. N.; LACA, E. A. Feeding behavior of steers on natural grasslands of Southern Brazil. In: INTERNATIONAL RANGELAND CONGRESS, 10., 2016, Saskatoon. The future management of grazing and wild lands in a high-tech world: proceedings. Saskatoon: IRCC, 2016. p. 220-221. 1 pen-drive.| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| 9. | | MARÍN GÓMEZ, A.; LACA, E. A.; BALDISSERA, T. C.; PINTO, C. E.; GARAGORRY, F. C.; ZUBIETA, A. S.; BREMM, C.; BINDELLE, J.; CARVALHO, P. C. de F. Determining the pre-grazing sward height of Kikuyu grass (Cenchrus clandestinus - Hochst. ex Chiov.) for optimizing nutrient intake rate of dairy heifers. PLos One, v. 17, n. 7, e0269716, July 2022.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 1 |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| 10. | | BREMM, C.; CARVALHO, P. C. F.; FONSECA, L.; AMARAL, G. A.; MEZZALIRA, J. C.; PEREZ, N. B.; NABINGER, C.; LACA, E. A. Diet switching by mammalian herbivores in response to exotic grass invasion. Plos One, v. 11, n. 2, e0150167, 26 fev. 2016.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 1 |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| 11. | | GENRO, T. C. M.; FEDRIGO, J. K.; PINTO, C. E.; NEVES, F. P.; TRINDADE, J. K.; CARVALHO, C. P. C. F.; NABINGER, C.; LACA, E. A. Structural traits in natural grassland grazed by heifers in Southern Brazil. In: INTERNATIONAL RANGELAND CONGRESS, 9., 2011, Rosario, Argentina. Diverse rangelands for a sustainable society: [proceedings...]. Rosario: Instituto Nacional de Tecnología Agrpecuaria; Asociación Argentina para el Manejo de Pastizales Naturales, 2011. p. 402.| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| 12. | | GENRO, T. C. M.; CARVALHO, P. C.; SOCA, P.; GARCIA, E. N.; NABINGER, C.; AMARAL, G. do A.; BREMM, C.; LACA, E. A. Técnicas para estimativa de consumo sob pastejo. In: SIMPÓSIO SOBRE MANEJO ESTRATÉGICO DA PASTAGEM, 6., SIMPÓSIO INTERNACIONAL SOBRE PRODUÇÃO ANIMAL EM PASTEJO, 4., 2012, Viçosa, MG. Anais... Viçosa, MG: UFV, DZO, 2012. p. 21-51.| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| 13. | | CARVALHO, P. C. F.; BREMM, C.; MEZZALIRA, J. C.; FONSECA, L.; TRINDADE, J. K.; BONNET, O. J. F.; TISCHLER, M.; GENRO, T. C. M.; NABINGER, C.; LACA, E. A. Can animal performance be predicted from short-term grazing processes? Animal Production Science, v. 55, n. 3, p. 319-327, 2015.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: B - 1 |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| 14. | | ROSSETTO, J.; GENRO, T. C. M.; FARIA, B. M. de; PRATES, E. R.; SANTOS, A. de S.; VELHO, J. P.; TRINDADE, J. P. P.; PEREIRA, L. G. R.; ZUBIETA, A. S.; LACA, E. A. Nutritional groups of herbaceous species from the Pampas grasslands. In: INTERNATIONAL RANGELAND CONGRESS, 10., 2016, Saskatoon. The future management of grazing and wild lands in a high-tech world: proceedings. Saskatoon: IRCC, 2016. p. 222-223. 1 pen-drive.| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| Registros recuperados : 14 | |
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| Nenhum registro encontrado para a expressão de busca informada. |
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