Random regressions models to describe the genetic variation of milk yield over multiple parities in buffaloes

dc.contributor.authorSesana, R. C. [UNESP]
dc.contributor.authorBignardi, A. B. [UNESP]
dc.contributor.authorEl Faro, L.
dc.contributor.authorSeno, L. O. [UNESP]
dc.contributor.authorBorquis, R. R.A. [UNESP]
dc.contributor.authorAlbuquerque, L. G. [UNESP]
dc.contributor.authorTonhati, H. [UNESP]
dc.contributor.institutionUniversidade Estadual Paulista (UNESP)
dc.contributor.institutionAgência Paulista de Tecnologia dos Agronegócios (Apta) - SP
dc.contributor.institutionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.date.accessioned2022-04-29T07:12:12Z
dc.date.available2022-04-29T07:12:12Z
dc.date.issued2007-12-01
dc.description.abstractThe objectives of this study were to estimate (co)variance functions for additive genetic and permanent environmental effects, as well as the genetic parameters for milk yield over multiple parities, using random regressions models (RRM). Records of 4,757 complete lactations of Murrah breed buffaloes from 12 herds were analyzed. Ages at calving were between 2 and 11 years. The model included the additive genetic and permanent environmental random effects and the fixed effects of contemporary groups (herd, year and calving season) and milking frequency (1 or 2). A cubic regression on Legendre orthogonal polynomials of ages was used to model the mean trend. The additive genetic and permanent environmental effects were modeled by Legendre orthogonal polynomials. Residual variances were considered homogenous or heterogeneous, modeled through variance functions or step functions with 5, 7 or 10 classes. Results from Akaike's and Schwarz's Bayesian information criterion indicated that a RRM considering a third order polynomial for the additive genetic and permanent environmental effects and a step function with 5 classes for residual variances fitted best. Heritability estimates obtained by this model varied from 0.10 to 0.28. Genetic correlations were high between consecutive ages, but decreased when intervals between ages increased.en
dc.description.affiliationUniversity of São Paulo Station Departamento de Zootecnia Universidade Estadual Paulista (UNESP), 14884-000 - Jaboticabal, SP
dc.description.affiliationAgência Paulista de Tecnologia dos Agronegócios (Apta) - SP
dc.description.affiliationConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.description.affiliationUnespUniversity of São Paulo Station Departamento de Zootecnia Universidade Estadual Paulista (UNESP), 14884-000 - Jaboticabal, SP
dc.description.sponsorshipFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.format.extent364-367
dc.identifierhttp://dx.doi.org/10.4081/ijas.2007.s2.364
dc.identifier.citationItalian Journal of Animal Science, v. 6, n. SUPPL. 2, p. 364-367, 2007.
dc.identifier.doi10.4081/ijas.2007.s2.364
dc.identifier.issn1594-4077
dc.identifier.scopus2-s2.0-84885607554
dc.identifier.urihttp://hdl.handle.net/11449/227227
dc.language.isoeng
dc.relation.ispartofItalian Journal of Animal Science
dc.sourceScopus
dc.subjectGenetic parameters
dc.subjectLegendre polynomials
dc.subjectMilk yield
dc.titleRandom regressions models to describe the genetic variation of milk yield over multiple parities in buffaloesen
dc.typeArtigo
unesp.departmentZootecnia - FCAVpt

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