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Registro Completo |
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Biblioteca(s): |
Embrapa Agricultura Digital. |
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Data corrente: |
15/04/2009 |
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Data da última atualização: |
10/08/2009 |
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Autoria: |
SCHÖFFEL, E. R.; VOLPE, C. A. |
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Afiliação: |
EDGAR RICARDO SCHÖFFEL, FAEM/UFPEL; CLOVIS ALBERTO VOLPE, FCAV/UNESP. |
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Título: |
Redução relativa da velocidade do vento com quebra-ventos de diferentes porosidades. |
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Ano de publicação: |
2005 |
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Fonte/Imprenta: |
Revista Brasileira de Agrometeorologia, Piracicaba, v. 13, n. 2, p. 284-291, 2005. |
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Idioma: |
Português |
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Conteúdo: |
Os quebra-ventos proporcionam proteção aos humanos, aos animais e às plantas. A eficácia dos quebra-ventos pode ser avaliada por alguns índices existentes na bibliografia. O propósito deste trabalho foi reavaliar a relação existente entre a redução relativa da velocidade do vento com a velocidade do vento a barlavento através de medidas de campo com quebra-ventos artificiais de diferentes porosidades. Foram utilizados quebra-ventos com porosidades de 82%, 70%, 50% e 30% e considerou-se apenas vento com ângulo de incidência superior a 70o em relação à barreira. A porosidade exerceu grande efeito sobre a redução relativa da velocidade do vento a sotavento. Quebra-ventos de baixa porosidade proporcionam maior redução da velocidade do vento a sotavento mas essa redução varia também em função da distância do quebra-vento e da magnitude da velocidade do vento a barlavento. Para velocidades do vento inferiores a 4 m s-1 a redução relativa da velocidade do vento aumentou com o aumento da velocidade do vento a barlavento mas aumentou, também, a variabilidade desses dados. |
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Palavras-Chave: |
Barreira; Densidade; Redução do vento. |
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Thesagro: |
Quebra-Vento; Vento. |
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Categoria do assunto: |
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Marc: |
LEADER 01669naa a2200193 a 4500
001 1031993
005 2009-08-10
008 2005 bl uuuu u00u1 u #d
100 1 $aSCHÖFFEL, E. R.
245 $aRedução relativa da velocidade do vento com quebra-ventos de diferentes porosidades.
260 $c2005
520 $aOs quebra-ventos proporcionam proteção aos humanos, aos animais e às plantas. A eficácia dos quebra-ventos pode ser avaliada por alguns índices existentes na bibliografia. O propósito deste trabalho foi reavaliar a relação existente entre a redução relativa da velocidade do vento com a velocidade do vento a barlavento através de medidas de campo com quebra-ventos artificiais de diferentes porosidades. Foram utilizados quebra-ventos com porosidades de 82%, 70%, 50% e 30% e considerou-se apenas vento com ângulo de incidência superior a 70o em relação à barreira. A porosidade exerceu grande efeito sobre a redução relativa da velocidade do vento a sotavento. Quebra-ventos de baixa porosidade proporcionam maior redução da velocidade do vento a sotavento mas essa redução varia também em função da distância do quebra-vento e da magnitude da velocidade do vento a barlavento. Para velocidades do vento inferiores a 4 m s-1 a redução relativa da velocidade do vento aumentou com o aumento da velocidade do vento a barlavento mas aumentou, também, a variabilidade desses dados.
650 $aQuebra-Vento
650 $aVento
653 $aBarreira
653 $aDensidade
653 $aRedução do vento
700 1 $aVOLPE, C. A.
773 $tRevista Brasileira de Agrometeorologia, Piracicaba$gv. 13, n. 2, p. 284-291, 2005.
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Registro original: |
Embrapa Agricultura Digital (CNPTIA) |
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 | Acesso ao texto completo restrito à biblioteca da Embrapa Pecuária Sul. Para informações adicionais entre em contato com cppsul.biblioteca@embrapa.br. |
Registro Completo
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Biblioteca(s): |
Embrapa Pecuária Sul. |
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Data corrente: |
15/12/2017 |
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Data da última atualização: |
15/12/2017 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
A - 1 |
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Autoria: |
MACNEIL, M. D.; CARDOSO, F. F.; HAY, E. |
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Afiliação: |
M. D. MacNeil; FERNANDO FLORES CARDOSO, CPPSUL; E. Hay. |
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Título: |
Genotype by environment interaction effects in genetic evaluation of preweaning gain for Line 1 Hereford cattle from Miles City, Montana. |
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Ano de publicação: |
2017 |
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Fonte/Imprenta: |
Journal of Animal Science, v. 95, n. 9, p. 3833-3838, 2017. |
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Idioma: |
Inglês |
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Conteúdo: |
It has long been recognized that genotype × environment interaction potentially influences genetic evaluation of beef cattle. However, this recognition has largely been ignored in systems for national cattle evaluation. The objective of this investigation was to determine if direct and maternal genetic effects on preweaning gain would be reranked depending on an environmental gradient as determined by year effects. Data used were from the 76-yr selection experiment with the Line 1 Hereford cattle raised at Miles City, MT. The data comprised recorded phenotypes from 7,566 animals and an additional 1,862 ancestral records included in the pedigree. The presence of genotype × environment interaction was examined using reaction norms wherein year effects on preweaning gain were hypothesized to linearly influence the EBV. Estimates of heritability for direct and maternal effects, given the average environment, were 10 ± 2 and 26 ± 3%, respectively. In an environment that is characterized by the 5th (95th) percentile of the distribution of year effects, the corresponding estimates of heritability were 18 ± 3 (22 ± 3%) and 30 ± 3% (30 ± 3%), respectively. Rank correlations of direct and maternal EBV appropriate to the 5th and 95th percentiles of the year effects were 0.67 and 0.92, respectively. In the average environment, the genetic trends were 255 ± 1 g/yr for direct effects and 557 ± 3 g/yr for maternal effects. In the fifth percentile environment, the corresponding estimates of genetic trend were 271 ± 1 and 540 ± 3 g/yr, respectively, and in the 95th percentile environment, they were 236 ± 1 and 578 ± 3 g/yr, respectively. Linear genetic trends in environmental sensitivity were observed for both the direct (?8.06 × 10?? ± 0.49 × 10??) and maternal (8.72 × 10?? ± 0.43 × 10??) effects. Therefore, changing systems of national cattle evaluation to more fully account for potential genotype × environment interaction would improve the assessment of breeding stock, particularly for direct effects. Estimates of environmental sensitivity parameters could also facilitate identification of genetic limitations to production. MenosIt has long been recognized that genotype × environment interaction potentially influences genetic evaluation of beef cattle. However, this recognition has largely been ignored in systems for national cattle evaluation. The objective of this investigation was to determine if direct and maternal genetic effects on preweaning gain would be reranked depending on an environmental gradient as determined by year effects. Data used were from the 76-yr selection experiment with the Line 1 Hereford cattle raised at Miles City, MT. The data comprised recorded phenotypes from 7,566 animals and an additional 1,862 ancestral records included in the pedigree. The presence of genotype × environment interaction was examined using reaction norms wherein year effects on preweaning gain were hypothesized to linearly influence the EBV. Estimates of heritability for direct and maternal effects, given the average environment, were 10 ± 2 and 26 ± 3%, respectively. In an environment that is characterized by the 5th (95th) percentile of the distribution of year effects, the corresponding estimates of heritability were 18 ± 3 (22 ± 3%) and 30 ± 3% (30 ± 3%), respectively. Rank correlations of direct and maternal EBV appropriate to the 5th and 95th percentiles of the year effects were 0.67 and 0.92, respectively. In the average environment, the genetic trends were 255 ± 1 g/yr for direct effects and 557 ± 3 g/yr for maternal effects. In the fifth percentile environment, the corresponding estimates of... Mostrar Tudo |
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Thesagro: |
Gado de corte. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02697naa a2200157 a 4500
001 2082708
005 2017-12-15
008 2017 bl uuuu u00u1 u #d
100 1 $aMACNEIL, M. D.
245 $aGenotype by environment interaction effects in genetic evaluation of preweaning gain for Line 1 Hereford cattle from Miles City, Montana.$h[electronic resource]
260 $c2017
520 $aIt has long been recognized that genotype × environment interaction potentially influences genetic evaluation of beef cattle. However, this recognition has largely been ignored in systems for national cattle evaluation. The objective of this investigation was to determine if direct and maternal genetic effects on preweaning gain would be reranked depending on an environmental gradient as determined by year effects. Data used were from the 76-yr selection experiment with the Line 1 Hereford cattle raised at Miles City, MT. The data comprised recorded phenotypes from 7,566 animals and an additional 1,862 ancestral records included in the pedigree. The presence of genotype × environment interaction was examined using reaction norms wherein year effects on preweaning gain were hypothesized to linearly influence the EBV. Estimates of heritability for direct and maternal effects, given the average environment, were 10 ± 2 and 26 ± 3%, respectively. In an environment that is characterized by the 5th (95th) percentile of the distribution of year effects, the corresponding estimates of heritability were 18 ± 3 (22 ± 3%) and 30 ± 3% (30 ± 3%), respectively. Rank correlations of direct and maternal EBV appropriate to the 5th and 95th percentiles of the year effects were 0.67 and 0.92, respectively. In the average environment, the genetic trends were 255 ± 1 g/yr for direct effects and 557 ± 3 g/yr for maternal effects. In the fifth percentile environment, the corresponding estimates of genetic trend were 271 ± 1 and 540 ± 3 g/yr, respectively, and in the 95th percentile environment, they were 236 ± 1 and 578 ± 3 g/yr, respectively. Linear genetic trends in environmental sensitivity were observed for both the direct (?8.06 × 10?? ± 0.49 × 10??) and maternal (8.72 × 10?? ± 0.43 × 10??) effects. Therefore, changing systems of national cattle evaluation to more fully account for potential genotype × environment interaction would improve the assessment of breeding stock, particularly for direct effects. Estimates of environmental sensitivity parameters could also facilitate identification of genetic limitations to production.
650 $aGado de corte
700 1 $aCARDOSO, F. F.
700 1 $aHAY, E.
773 $tJournal of Animal Science$gv. 95, n. 9, p. 3833-3838, 2017.
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