Title:	Genetic evaluation using multi-trait and random regression models in Simmental beef cattle.
Authors:	MOTA, R. R. MARQUES, L. F. A. LOPES, P. S. SILVA, L. P. da RESENDE, M. D. V. de TORRES, R. A.
Affiliation:	UFV; UNIVERSIDADE FEDERAL DO ESPIRITO SANTO; UFV; UFV; MARCOS DEON VILELA DE RESENDE, CNPF; UFV.
Date Issued:	2013
Citation:	Genetics and Molecular Research, v. 12, n. 3, p. 2465-2480, 2013.
Description:	The Brazilian Association of Simmental and Simbrasil Cattle Farmers provided 29,510 records from 10,659 Simmental beef cattle; these were used to estimate (co)variance components and genetic parameters for weights in the growth trajectory, based on multi-trait (MTM) and random regression models (RRM). The (co)variance components and genetic parameters were estimated by restricted maximum likelihood. In the MTM analysis, the likelihood ratio test was used to determine the significance of random effects included in the model and to define the most appropriate model. All random effects were significant and included in the final model. In the RRM analysis, different adjustments of polynomial orders were compared for 5 different criteria to choose the best fit model. An RRM of third order for the direct additive genetic, direct permanent environmental, maternal additive genetic, and maternal permanent environment effects was sufficient to model variance structures in the growth trajectory of the animals. The (co)variance components were generally similar in MTM and RRM. Direct heritabilities of MTM were slightly lower than RRM and varied from 0.04 to 0.42 and 0.16 to 0.45, respectively. Additive direct correlations were mostly positive and of high magnitude, being highest at closest ages. Considering the results and that pre-adjustment of the weights to standard ages is not required, RRM is recommended for genetic evaluation of Simmental beef cattle in Brazil.
Thesagro:	Gado de Corte Peso
Keywords:	Simental Tragetória de crescimento Componente de variância
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CNPF)