HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: jas.2008-1173v1 87/5/1591    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Shiotsuki, L. Articles by Albuquerque, L. G. Search for Related Content PubMed PubMed Citation Articles by Shiotsuki, L. Articles by Albuquerque, L. G.

Genetic associations of sexual precocity with growth traits and visual scores of conformation, finishing, and muscling in Nelore cattle¹

L. Shiotsuki^*, J. A. V. Silva, II, H. Tonhati^* and L. G. Albuquerque^*,2,3

^* Faculdade de Ciências Agrárias e Veterinárias, São Paulo State University (UNESP), 14884-000, Jaboticabal, São Paulo, Brazil; and Pesquisador Alta Genetics Brazil, 38045-000, Uberaba, Minas Gerais, Brazil

² Corresponding author: lgalb{at}fcav.unesp.br

The objective of this study was to determine the possible use of heifer pregnancy at 16 mo as a selection criterion and its possible genetic associations with hip height, yearling weight, and visual scores of conformation, finishing, and muscling. The data set contained records of 56,458 Nelore yearlings for the traits described above. Covariance components were estimated by bivariate animal models assuming a linear model for hip height, yearling weight and conformation, and finishing and muscling scores, and a nonlinear (threshold) model for heifer pregnancy. Variance components were estimated using Bayesian inference. Flat distributions were used for all (co)variance components and genetic correlations. The first 5,000 rounds were considered as the burn-in period and discarded. The heritability estimate of heifer pregnancy indicates that the trait can be used as a selection criterion. Long-term selection for heifer pregnancy will result in a reduction of animal height. However, selection for increasing yearling weight should be possible in this population of Nelore cattle without having major effects on fertility. Selection for increasing visual scores of conformation, finishing, and muscling will result in small or no response in heifer pregnancy at 16 mo.

Key Words: Bayesian inference • heifer pregnancy • hip height • visual score