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![](/consulta/web/img/deny.png) | Acesso ao texto completo restrito à biblioteca da Embrapa Gado de Leite. Para informações adicionais entre em contato com cnpgl.biblioteca@embrapa.br. |
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Biblioteca(s): |
Embrapa Gado de Leite. |
Data corrente: |
15/02/2017 |
Data da última atualização: |
30/01/2023 |
Tipo da produção científica: |
Artigo em Periódico Indexado |
Autoria: |
KERN, E. L.; COBUCI, J. A.; COSTA, C. N.; DUCROCQ, V. |
Afiliação: |
Elisandra Lurdes Kern, UFRGS; Jaime Araujo Cobuci, UFRGS; CLAUDIO NAPOLIS COSTA, CNPGL; Vincent Ducrocq, INRA. |
Título: |
Survival analysis of productive life in Brazilian holstein using a piecewise Weibull proportional hazard model. |
Ano de publicação: |
2016 |
Fonte/Imprenta: |
Livestock Science, v. 185, p. 89-96, 2016. |
Idioma: |
Inglês |
Conteúdo: |
Abstract The objectives of this study were to assess the most important factors that influence productive life (PL) of Brazilian Holstein cows and to estimate genetic parameters for PL using a piecewise Weibull proportional hazard model. Records of PL from first calving to last recording (culling) of 132,922 cows coming from 945 herds were used. They had to have their first calving occurring between 1989 and 2013 and they were daughters of 6,804 sires. The model included the time-dependent effects of region within year, class of milk production within herd-year, class of milk production within lactation number, class of fat and protein contents within herd and (variation in) herd size as well as the time-independent fixed effect of age at first calving, the random effects of herd-year, sire and maternal grand sire. All fixed effects had a significant effect on PL (Po0.001). The relative risk (RR) for within herd class of milk yield varied from 3.16 for the worst 20% class to 0.41 for the best 20% class. RR also increased as protein and fat decreased, but to a lesser extent compared to milk yield. Significant effects on PL were found for regionyear, with large yearly changes in some cases. RR increased with age at first calving and with herd size but lower risks were observed when herd size was increasing or decreasing, compared to stable herds. The Weibull shape parameters (and therefore RR) increased with lactation number and with stage of lactation. The sire genetic variance estimate was 0.03070.002 which corresponds to an equivalent heritability estimate of 6.1% accounting for censoring. A positive genetic trend of PL was observed. These results may contribute to the development of a routine genetic evaluation necessary to improve PL of Brazilian Holsteins. MenosAbstract The objectives of this study were to assess the most important factors that influence productive life (PL) of Brazilian Holstein cows and to estimate genetic parameters for PL using a piecewise Weibull proportional hazard model. Records of PL from first calving to last recording (culling) of 132,922 cows coming from 945 herds were used. They had to have their first calving occurring between 1989 and 2013 and they were daughters of 6,804 sires. The model included the time-dependent effects of region within year, class of milk production within herd-year, class of milk production within lactation number, class of fat and protein contents within herd and (variation in) herd size as well as the time-independent fixed effect of age at first calving, the random effects of herd-year, sire and maternal grand sire. All fixed effects had a significant effect on PL (Po0.001). The relative risk (RR) for within herd class of milk yield varied from 3.16 for the worst 20% class to 0.41 for the best 20% class. RR also increased as protein and fat decreased, but to a lesser extent compared to milk yield. Significant effects on PL were found for regionyear, with large yearly changes in some cases. RR increased with age at first calving and with herd size but lower risks were observed when herd size was increasing or decreasing, compared to stable herds. The Weibull shape parameters (and therefore RR) increased with lactation number and with stage of lactation. The sire genetic varian... Mostrar Tudo |
Palavras-Chave: |
Environment effect; Genetic analysis. |
Thesaurus Nal: |
dairy cattle; longevity. |
Categoria do assunto: |
L Ciência Animal e Produtos de Origem Animal |
Marc: |
LEADER 02398naa a2200205 a 4500 001 2064218 005 2023-01-30 008 2016 bl uuuu u00u1 u #d 100 1 $aKERN, E. L. 245 $aSurvival analysis of productive life in Brazilian holstein using a piecewise Weibull proportional hazard model.$h[electronic resource] 260 $c2016 520 $aAbstract The objectives of this study were to assess the most important factors that influence productive life (PL) of Brazilian Holstein cows and to estimate genetic parameters for PL using a piecewise Weibull proportional hazard model. Records of PL from first calving to last recording (culling) of 132,922 cows coming from 945 herds were used. They had to have their first calving occurring between 1989 and 2013 and they were daughters of 6,804 sires. The model included the time-dependent effects of region within year, class of milk production within herd-year, class of milk production within lactation number, class of fat and protein contents within herd and (variation in) herd size as well as the time-independent fixed effect of age at first calving, the random effects of herd-year, sire and maternal grand sire. All fixed effects had a significant effect on PL (Po0.001). The relative risk (RR) for within herd class of milk yield varied from 3.16 for the worst 20% class to 0.41 for the best 20% class. RR also increased as protein and fat decreased, but to a lesser extent compared to milk yield. Significant effects on PL were found for regionyear, with large yearly changes in some cases. RR increased with age at first calving and with herd size but lower risks were observed when herd size was increasing or decreasing, compared to stable herds. The Weibull shape parameters (and therefore RR) increased with lactation number and with stage of lactation. The sire genetic variance estimate was 0.03070.002 which corresponds to an equivalent heritability estimate of 6.1% accounting for censoring. A positive genetic trend of PL was observed. These results may contribute to the development of a routine genetic evaluation necessary to improve PL of Brazilian Holsteins. 650 $adairy cattle 650 $alongevity 653 $aEnvironment effect 653 $aGenetic analysis 700 1 $aCOBUCI, J. A. 700 1 $aCOSTA, C. N. 700 1 $aDUCROCQ, V. 773 $tLivestock Science$gv. 185, p. 89-96, 2016.
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Embrapa Gado de Leite (CNPGL) |
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Biblioteca(s): |
Embrapa Semiárido. |
Data corrente: |
24/10/2003 |
Data da última atualização: |
13/07/2018 |
Tipo da produção científica: |
Resumo em Anais de Congresso |
Autoria: |
RESENDE, G. M. de; YURI, J. E.; MOTA, J. H.; SOUZA, R. J. de; FREITAS, S. A. C. de; RODRIGUES JÚNIOR, J. C. |
Afiliação: |
GERALDO MILANEZ DE RESENDE, CPATSA; JONY EISHI YURI. |
Título: |
Tipos de bandejas e idade de transplantio de mudas sobre o desenvolvimento e produtividade da alface americana. |
Ano de publicação: |
2003 |
Fonte/Imprenta: |
Horticultura Brasileira, Brasília, v. 21, n. 2, p. 301, jul. 2003. |
Idioma: |
Português |
Notas: |
Suplemento 1. Edição dos Resumos do 43 Congresso Brasileiro de Olericultura, Recife, jul. 2003. |
Conteúdo: |
Com o objetivo de avaliar a influência de tipos de bandeja e idade de transplantio das mudas de alface americana (Lactuca sativa L.) conduziu-se um ensaio no período de março a junho de 2002 no Município de Três Pontas, MG. |
Palavras-Chave: |
Massa fresca; Massa seca. |
Thesagro: |
Alface; Lactuca Sativa; Produtividade. |
Thesaurus NAL: |
Lactuca. |
Categoria do assunto: |
A Sistemas de Cultivo |
URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/179743/1/Horticultura-Brasileira-v.21-n.2-p.301-2003.pdf
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Marc: |
LEADER 01063nam a2200253 a 4500 001 1152156 005 2018-07-13 008 2003 bl uuuu u00u1 u #d 100 1 $aRESENDE, G. M. de 245 $aTipos de bandejas e idade de transplantio de mudas sobre o desenvolvimento e produtividade da alface americana. 260 $aHorticultura Brasileira, Brasília, v. 21, n. 2, p. 301, jul. 2003.$c2003 500 $aSuplemento 1. Edição dos Resumos do 43 Congresso Brasileiro de Olericultura, Recife, jul. 2003. 520 $aCom o objetivo de avaliar a influência de tipos de bandeja e idade de transplantio das mudas de alface americana (Lactuca sativa L.) conduziu-se um ensaio no período de março a junho de 2002 no Município de Três Pontas, MG. 650 $aLactuca 650 $aAlface 650 $aLactuca Sativa 650 $aProdutividade 653 $aMassa fresca 653 $aMassa seca 700 1 $aYURI, J. E. 700 1 $aMOTA, J. H. 700 1 $aSOUZA, R. J. de 700 1 $aFREITAS, S. A. C. de 700 1 $aRODRIGUES JÚNIOR, J. C.
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