Data/hora: 23/06/2024 03:48:47

Biblioteca(s): 	Embrapa Pecuária Sudeste.	
Data corrente: 	05/10/2010	
Data da última atualização: 	30/06/2023	
Autoria: 	BALDI, F.; ALBUQUERQUE, L. G.; ALENCAR, M. M. de.	
Afiliação: 	FERNANDO BALDI, UNESP/JABOTICABAL; LUCIA G. ALBUQUERQUE, UNESP/JABOTICABAL; MAURICIO MELLO DE ALENCAR, CPPSE.	
Título: 	Random regression models on Legendre polynomials to estimate genetic parameters for weights from birth to adult age in Canchim cattle.	
Ano de publicação: 	2010	
Fonte/Imprenta: 	Journal of Animal Breeding and Genetics, v. 127, n. 4, p. 289-299, 2010	
Idioma: 	Português	
Conteúdo: 	The objective of this work was to estimate covariance functions for direct and maternal genetic effects, animal and maternal permanent environmental effects, and subsequently, to derive relevant genetic parameters for growth traits in Canchim cattle. Data comprised 49 011 weight records on 2435 females from birth to adult age. The model of analysis included fixed effects of contemporary groups (year and month of birth and at weighing) and age of dam as quadratic covariable. Mean trends were taken into account by a cubic regression on orthogonal polynomials of animal age. Residual variances were allowed to vary and were modelled by a step function with 1, 4 or 11 classes based on animal's age. The model fitting four classes of residual variances was the best. A total of 12 random regression models from second to seventh order were used to model direct and maternal genetic effects, animal and maternal permanent environmental effects. The model with direct and maternal genetic effects, animal and maternal permanent environmental effects fitted by quadric, cubic, quintic and linear Legendre polynomials, respectively, was the most adequate to describe the covariance structure of the data. Estimates of direct and maternal heritability obtained by multi-trait (seven traits) and random regression models were very similar. Selection for higher weight at any age, especially after weaning, will produce an increase in mature cow weight. The possibility to modify the growth curve in Canchim cattle to obtain animals with rapid growth at early ages and moderate to low mature cow weight is limited.	
Palavras-Chave: 	Covariance functions; Growth curve; Legendre polynomials.	
Thesaurus Nal: 	beef cattle.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Pecuária Sudeste (CPPSE)	
Exemplares: 	CPPSE - (19529-1) - UPC - AP - DD - PROCI-2010.00086 - BAL - 2010.00086 - DIS