Contemporary group alternatives for genetic evaluation of milk yield in small populations of dairy cattle
Autor(a) principal: | |
---|---|
Data de Publicação: | 2019 |
Outros Autores: | , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1071/AN17551 http://hdl.handle.net/11449/186731 |
Resumo: | In the present study, different random regression models, focussed on the nature of the effect of the contemporary group, fixed or random, were compared for genetic evaluation of test-day milk yield in dairy Gir breed, whose herds are characterised by relatively reduced numbers of cows. Cows were assigned to the same contemporary group if they were tested in the same herd, year and month. In one of the evaluated models, the contemporary group was investigated as a fixed effect and a clustering procedure was adopted to group herd-year subclasses in order to, at the end of the process, all contemporary groups contained at least three cows. The models were compared by the quality of fit, the accuracy of the predicted breeding values and their estimates of genetic parameters. The clustering procedure did not significantly improve the accuracy of predicted breeding values. Moreover, the fit to the data for this model was negatively affected. Therefore, this strategy should not be further implemented. The model including the herd-calving period effect and contemporary group treated as random effect showed similar characteristics to its equivalent, where the contemporary group was modelled as a fixed effect. However, the fit to the data for this model was slightly worse. Thus, the results suggest a random regression model including the herd-calving period effect and the fixed effect of contemporary group for the genetic evaluations of production traits in dairy Gir cattle. These findings could be extended to small dairy cattle populations whose herds are small-sized. |
id |
UNSP_9ca8965edbd825bec11e374c7405becc |
---|---|
oai_identifier_str |
oai:repositorio.unesp.br:11449/186731 |
network_acronym_str |
UNSP |
network_name_str |
Repositório Institucional da UNESP |
repository_id_str |
2946 |
spelling |
Contemporary group alternatives for genetic evaluation of milk yield in small populations of dairy cattleanimal breedingdairy milk productiongenetic correlationgenetic heritabilityIn the present study, different random regression models, focussed on the nature of the effect of the contemporary group, fixed or random, were compared for genetic evaluation of test-day milk yield in dairy Gir breed, whose herds are characterised by relatively reduced numbers of cows. Cows were assigned to the same contemporary group if they were tested in the same herd, year and month. In one of the evaluated models, the contemporary group was investigated as a fixed effect and a clustering procedure was adopted to group herd-year subclasses in order to, at the end of the process, all contemporary groups contained at least three cows. The models were compared by the quality of fit, the accuracy of the predicted breeding values and their estimates of genetic parameters. The clustering procedure did not significantly improve the accuracy of predicted breeding values. Moreover, the fit to the data for this model was negatively affected. Therefore, this strategy should not be further implemented. The model including the herd-calving period effect and contemporary group treated as random effect showed similar characteristics to its equivalent, where the contemporary group was modelled as a fixed effect. However, the fit to the data for this model was slightly worse. Thus, the results suggest a random regression model including the herd-calving period effect and the fixed effect of contemporary group for the genetic evaluations of production traits in dairy Gir cattle. These findings could be extended to small dairy cattle populations whose herds are small-sized.Univ Fed Mato Grosso, Inst Ciencias Agr & Tecnol, Grp Melhoramento Anim Mato Grosso GMAT, Campus Univ Rondonopolis, BR-78735901 Rondonopolis, MT, BrazilUniv Guelph, Anim & Poultry Sci Dept, Ctr Genet Improvement Livestock, Guelph, ON N1G 2W1, CanadaBeef Improvement Opportun, Guelph, ON, CanadaAgencia Paulista Tecnol Agronegocios, Inst Zootecnia, BR-14160900 Sertaozinho, SP, BrazilAssoc Brasileira Criadores Zebu, BR-38022330 Uberaba, MG, BrazilUniv Estadual Paulista, Fac Ciencias Agr & Vet, BR-14870000 Jaboticabal, SP, BrazilUniv Estadual Paulista, Fac Ciencias Agr & Vet, BR-14870000 Jaboticabal, SP, BrazilCsiro PublishingUniversidade Federal de Mato Grosso do Sul (UFMS)Univ GuelphBeef Improvement OpportunAgencia Paulista Tecnol AgronegociosAssoc Brasileira Criadores ZebuUniversidade Estadual Paulista (Unesp)Pereira, R. J.Schenkel, F. S.Ventura, R. V.Ayres, D. R.El Faro, L.Machado, C. H. C.Albuquerque, L. G. [UNESP]2019-10-06T00:01:23Z2019-10-06T00:01:23Z2019-01-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article1022-1030http://dx.doi.org/10.1071/AN17551Animal Production Science. Clayton: Csiro Publishing, v. 59, n. 6, p. 1022-1030, 2019.1836-0939http://hdl.handle.net/11449/18673110.1071/AN17551WOS:000466540400003Web of Sciencereponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengAnimal Production Scienceinfo:eu-repo/semantics/openAccess2021-10-23T20:17:59Zoai:repositorio.unesp.br:11449/186731Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462021-10-23T20:17:59Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Contemporary group alternatives for genetic evaluation of milk yield in small populations of dairy cattle |
title |
Contemporary group alternatives for genetic evaluation of milk yield in small populations of dairy cattle |
spellingShingle |
Contemporary group alternatives for genetic evaluation of milk yield in small populations of dairy cattle Pereira, R. J. animal breeding dairy milk production genetic correlation genetic heritability |
title_short |
Contemporary group alternatives for genetic evaluation of milk yield in small populations of dairy cattle |
title_full |
Contemporary group alternatives for genetic evaluation of milk yield in small populations of dairy cattle |
title_fullStr |
Contemporary group alternatives for genetic evaluation of milk yield in small populations of dairy cattle |
title_full_unstemmed |
Contemporary group alternatives for genetic evaluation of milk yield in small populations of dairy cattle |
title_sort |
Contemporary group alternatives for genetic evaluation of milk yield in small populations of dairy cattle |
author |
Pereira, R. J. |
author_facet |
Pereira, R. J. Schenkel, F. S. Ventura, R. V. Ayres, D. R. El Faro, L. Machado, C. H. C. Albuquerque, L. G. [UNESP] |
author_role |
author |
author2 |
Schenkel, F. S. Ventura, R. V. Ayres, D. R. El Faro, L. Machado, C. H. C. Albuquerque, L. G. [UNESP] |
author2_role |
author author author author author author |
dc.contributor.none.fl_str_mv |
Universidade Federal de Mato Grosso do Sul (UFMS) Univ Guelph Beef Improvement Opportun Agencia Paulista Tecnol Agronegocios Assoc Brasileira Criadores Zebu Universidade Estadual Paulista (Unesp) |
dc.contributor.author.fl_str_mv |
Pereira, R. J. Schenkel, F. S. Ventura, R. V. Ayres, D. R. El Faro, L. Machado, C. H. C. Albuquerque, L. G. [UNESP] |
dc.subject.por.fl_str_mv |
animal breeding dairy milk production genetic correlation genetic heritability |
topic |
animal breeding dairy milk production genetic correlation genetic heritability |
description |
In the present study, different random regression models, focussed on the nature of the effect of the contemporary group, fixed or random, were compared for genetic evaluation of test-day milk yield in dairy Gir breed, whose herds are characterised by relatively reduced numbers of cows. Cows were assigned to the same contemporary group if they were tested in the same herd, year and month. In one of the evaluated models, the contemporary group was investigated as a fixed effect and a clustering procedure was adopted to group herd-year subclasses in order to, at the end of the process, all contemporary groups contained at least three cows. The models were compared by the quality of fit, the accuracy of the predicted breeding values and their estimates of genetic parameters. The clustering procedure did not significantly improve the accuracy of predicted breeding values. Moreover, the fit to the data for this model was negatively affected. Therefore, this strategy should not be further implemented. The model including the herd-calving period effect and contemporary group treated as random effect showed similar characteristics to its equivalent, where the contemporary group was modelled as a fixed effect. However, the fit to the data for this model was slightly worse. Thus, the results suggest a random regression model including the herd-calving period effect and the fixed effect of contemporary group for the genetic evaluations of production traits in dairy Gir cattle. These findings could be extended to small dairy cattle populations whose herds are small-sized. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-10-06T00:01:23Z 2019-10-06T00:01:23Z 2019-01-01 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1071/AN17551 Animal Production Science. Clayton: Csiro Publishing, v. 59, n. 6, p. 1022-1030, 2019. 1836-0939 http://hdl.handle.net/11449/186731 10.1071/AN17551 WOS:000466540400003 |
url |
http://dx.doi.org/10.1071/AN17551 http://hdl.handle.net/11449/186731 |
identifier_str_mv |
Animal Production Science. Clayton: Csiro Publishing, v. 59, n. 6, p. 1022-1030, 2019. 1836-0939 10.1071/AN17551 WOS:000466540400003 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Animal Production Science |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
1022-1030 |
dc.publisher.none.fl_str_mv |
Csiro Publishing |
publisher.none.fl_str_mv |
Csiro Publishing |
dc.source.none.fl_str_mv |
Web of Science reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1799965433496862720 |