Estimation of genetic parameters for test-day milk yield in Holstein cows using a random regression model
Autor(a) principal: | |
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Data de Publicação: | 2005 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Genetics and Molecular Biology |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000100013 |
Resumo: | Test-day milk yield records of 11,023 first-parity Holstein cows were used to estimate genetic parameters for milk yield during different lactation periods. (Co)variance components were estimated using two random regression models, RRM1 and RRM2, and the restricted maximum likelihood method, compared by the likelihood ratio test. Additive genetic variances determined by RRM1 and additive genetic and permanent environmental variances estimated by RRM2 were described, using the Wilmink function. Residual variance was constant throughout lactation for the two models. The heritability estimates obtained by RRM1 (0.34 to 0.56) were higher than those obtained by RRM2 (0.15 to 0.31). Due to the high heritability estimates for milk yield throughout lactation and the negative genetic correlation between test-day yields during different lactation periods, the RRM1 model did not fit the data. Overall, genetic correlations between individual test days tended to decrease at the extremes of the lactation trajectory, showing values close to unity for adjacent test days. The inclusion of random regression coefficients to describe permanent environmental effects led to a more precise estimation of genetic and non-genetic effects that influence milk yield. |
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Genetics and Molecular Biology |
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Estimation of genetic parameters for test-day milk yield in Holstein cows using a random regression modelrandom regression modelsREML methodgenetic parameterstest-day milk yieldHolstein cowsTest-day milk yield records of 11,023 first-parity Holstein cows were used to estimate genetic parameters for milk yield during different lactation periods. (Co)variance components were estimated using two random regression models, RRM1 and RRM2, and the restricted maximum likelihood method, compared by the likelihood ratio test. Additive genetic variances determined by RRM1 and additive genetic and permanent environmental variances estimated by RRM2 were described, using the Wilmink function. Residual variance was constant throughout lactation for the two models. The heritability estimates obtained by RRM1 (0.34 to 0.56) were higher than those obtained by RRM2 (0.15 to 0.31). Due to the high heritability estimates for milk yield throughout lactation and the negative genetic correlation between test-day yields during different lactation periods, the RRM1 model did not fit the data. Overall, genetic correlations between individual test days tended to decrease at the extremes of the lactation trajectory, showing values close to unity for adjacent test days. The inclusion of random regression coefficients to describe permanent environmental effects led to a more precise estimation of genetic and non-genetic effects that influence milk yield.Sociedade Brasileira de Genética2005-03-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000100013Genetics and Molecular Biology v.28 n.1 2005reponame:Genetics and Molecular Biologyinstname:Sociedade Brasileira de Genética (SBG)instacron:SBG10.1590/S1415-47572005000100013info:eu-repo/semantics/openAccessCobuci,Jaime AraujoEuclydes,Ricardo FredericoLopes,Paulo SávioCosta,Claudio NapolisTorres,Robledo de AlmeidaPereira,Carmen Silvaeng2005-09-08T00:00:00Zoai:scielo:S1415-47572005000100013Revistahttp://www.gmb.org.br/ONGhttps://old.scielo.br/oai/scielo-oai.php||editor@gmb.org.br1678-46851415-4757opendoar:2005-09-08T00:00Genetics and Molecular Biology - Sociedade Brasileira de Genética (SBG)false |
dc.title.none.fl_str_mv |
Estimation of genetic parameters for test-day milk yield in Holstein cows using a random regression model |
title |
Estimation of genetic parameters for test-day milk yield in Holstein cows using a random regression model |
spellingShingle |
Estimation of genetic parameters for test-day milk yield in Holstein cows using a random regression model Cobuci,Jaime Araujo random regression models REML method genetic parameters test-day milk yield Holstein cows |
title_short |
Estimation of genetic parameters for test-day milk yield in Holstein cows using a random regression model |
title_full |
Estimation of genetic parameters for test-day milk yield in Holstein cows using a random regression model |
title_fullStr |
Estimation of genetic parameters for test-day milk yield in Holstein cows using a random regression model |
title_full_unstemmed |
Estimation of genetic parameters for test-day milk yield in Holstein cows using a random regression model |
title_sort |
Estimation of genetic parameters for test-day milk yield in Holstein cows using a random regression model |
author |
Cobuci,Jaime Araujo |
author_facet |
Cobuci,Jaime Araujo Euclydes,Ricardo Frederico Lopes,Paulo Sávio Costa,Claudio Napolis Torres,Robledo de Almeida Pereira,Carmen Silva |
author_role |
author |
author2 |
Euclydes,Ricardo Frederico Lopes,Paulo Sávio Costa,Claudio Napolis Torres,Robledo de Almeida Pereira,Carmen Silva |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Cobuci,Jaime Araujo Euclydes,Ricardo Frederico Lopes,Paulo Sávio Costa,Claudio Napolis Torres,Robledo de Almeida Pereira,Carmen Silva |
dc.subject.por.fl_str_mv |
random regression models REML method genetic parameters test-day milk yield Holstein cows |
topic |
random regression models REML method genetic parameters test-day milk yield Holstein cows |
description |
Test-day milk yield records of 11,023 first-parity Holstein cows were used to estimate genetic parameters for milk yield during different lactation periods. (Co)variance components were estimated using two random regression models, RRM1 and RRM2, and the restricted maximum likelihood method, compared by the likelihood ratio test. Additive genetic variances determined by RRM1 and additive genetic and permanent environmental variances estimated by RRM2 were described, using the Wilmink function. Residual variance was constant throughout lactation for the two models. The heritability estimates obtained by RRM1 (0.34 to 0.56) were higher than those obtained by RRM2 (0.15 to 0.31). Due to the high heritability estimates for milk yield throughout lactation and the negative genetic correlation between test-day yields during different lactation periods, the RRM1 model did not fit the data. Overall, genetic correlations between individual test days tended to decrease at the extremes of the lactation trajectory, showing values close to unity for adjacent test days. The inclusion of random regression coefficients to describe permanent environmental effects led to a more precise estimation of genetic and non-genetic effects that influence milk yield. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005-03-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000100013 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000100013 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S1415-47572005000100013 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Genética |
publisher.none.fl_str_mv |
Sociedade Brasileira de Genética |
dc.source.none.fl_str_mv |
Genetics and Molecular Biology v.28 n.1 2005 reponame:Genetics and Molecular Biology instname:Sociedade Brasileira de Genética (SBG) instacron:SBG |
instname_str |
Sociedade Brasileira de Genética (SBG) |
instacron_str |
SBG |
institution |
SBG |
reponame_str |
Genetics and Molecular Biology |
collection |
Genetics and Molecular Biology |
repository.name.fl_str_mv |
Genetics and Molecular Biology - Sociedade Brasileira de Genética (SBG) |
repository.mail.fl_str_mv |
||editor@gmb.org.br |
_version_ |
1752122379440488448 |