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This Article Full Text (PDF) All Versions of this Article: jas.2007-0636v1 87/2/516    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 Vergara, O. D. Articles by Ossa, G. A. Search for Related Content PubMed PubMed Citation Articles by Vergara, O. D. Articles by Ossa, G. A.

Direct genetic, maternal genetic, and heterozygosity effects on weaning weight in a Colombian multibreed beef cattle population

O. D. Vergara^*,, M. F. Ceron-Muñoz^*, E. M. Arboleda^*, Y. Orozco^* and G. A. Ossa^#

^* Universidad de Antioquia, Facultad de Ciencias Agrarias, Grupo de Investigación de Genética y Mejoramiento Animal, Medellín, Colombia , Universidad de Córdoba, Facultad de Medicina Veterinaria y Zootecnia, Montería, Colombia, Postal Code 354 ^# Centro de Investigaciones Turipana Corpoica, Montería, Colombia

overgara{at}sinu.unicordoba.edu.co

Abstract

The (co)variance components of weight at weaning (WW) were estimated for a Colombian multibreed beef cattle population. A single-trait animal model was used. The model included the fixed effect of contemporary group (sex, season, and year), and covariates such as: age of calf at weaning, age of cow, individual and maternal heterozygosity proportions, and breed percentage. Direct genetic, maternal genetic, permanent environment, and residual effects were included as random effects. Direct, maternal, and total heritabilities were 0.23 ± 0.047, 0.15 ± 0.041, and 0.19, respectively. The genetic correlation between direct and maternal effects was -0.42 ± 0.131, indicating that there may be antagonism among genes for growth and genes for maternal ability, which in turn suggests that improving WW by direct and maternal Expected Progeny Differences (EPDs) may be difficult. A greater value for the direct heterosis effect compared with the maternal heterosis effect was found. Furthermore, the higher the proportion of Angus, Romosinuano, and Blanco Orejinegro breeds, the lower the WW.

Key Words: beef cattle • genetic parameters • heterozygosity