Estimates of covariance functions for growth from birth to 630 days of age in Nelore cattle


Autoria(s): Albuquerque, L. G.; Meyer, K.
Contribuinte(s)

Universidade Estadual Paulista (UNESP)

Data(s)

27/05/2014

27/05/2014

01/12/2001

Resumo

Weight records of Brazilian Nelore cattle, from birth to 630 d of age, recorded every 3 mo, were analyzed using random regression models. Independent variables were Legendre polynomials of age at recording. The model of analysis included contemporary groups as fixed effects and age of dam as a linear and quadratic covariable. Mean trends were modeled through a cubic regression on orthogonal polynomials of age. Up to four sets of random regression coefficients were fitted for animals' direct and maternal, additive genetic, and permanent environmental effects. Changes in measurement error variances with age were modeled through a variance function. Orders of polyno-mial fit from three to six were considered, resulting in up to 77 parameters to be estimated. Models fitting random regressions modeled the pattern of variances in the data adequately, with estimates similar to those from corresponding univariate analysis. Direct heritability estimates decreased after birth and tended to be lowest at ages at which maternal effect estimates tended to be highest. Maternal heritability estimates increased after birth to a peak around 110 to 120 d of age and decreased thereafter. Additive genetic direct correlation estimates between weights at standard ages (birth, weaning, yearling, and final weight) were moderate to high and maternal genetic and environmental correlations were consistently high. © 2001 American Society of Animal Science. All rights reserved.

Formato

2776-2789

Identificador

http://www.journalofanimalscience.org/content/79/11/2776.long

Journal of Animal Science, v. 79, n. 11, p. 2776-2789, 2001.

0021-8812

http://hdl.handle.net/11449/66724

WOS:000172643000004

2-s2.0-0035515869

2-s2.0-0035515869.pdf

Idioma(s)

eng

Relação

Journal of Animal Science

Direitos

openAccess

Palavras-Chave #Beef cattle #Growth #Heritability #Maternal effects #Zebu breeds
Tipo

info:eu-repo/semantics/article