USE OF RANDOM REGRESSION MODELS FOR ESTIMATION OF GENETIC PARAMETERS IN TABAPUÃ CATTLE

Authors

Abstract

In this study 28,643 weight records taken from birth to 660 days of age from 6,471 animals of the Tabapuã zebu breed were used to estimate (co)variance components and genetic parameters using a random regression model. The data were analyzed with the DFREML program applying the Restricted Maximum Likelihood method and using an AIREML algorithm. In the models, direct additive genetic, maternal, and permanent environmental (animal and maternal) effects were assumed to be random, contemporary groups were included as fixed effects, and the ages of animal at weighing and of dam at calving were used as covariables. Estimates of direct additive genetic variance increased with age. Heritability estimates for direct additive effect decreased from birth to weaning, whereas estimates of maternal heritability increased over this period and decreased at older ages. Direct genetic correlations ranged from moderate to high, so their magnitudes decreased with greater age gaps between animals. The random regression model used in this study was appropriate to describe changes in variance estimates for weights in Tabapuã cattle raised in the Brazilian state of Bahia.
Keywords: animal model, beef cattle, heritability, selection.

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Author Biographies

Severino Cavalcante Sousa Junior, Universidade federal do Piauí

Zootecnista formado pela Universidade Estadual Vale do Acaraú - UVA, com Mestrado em Melhoramento Genético pela Universidade Federal do Ceará, doutor em Melhoramento Genético Animal na Universidade Estadual Paulista Júlio Mesquita Filho - Unesp Jaboticabal. - UFC e Atualmente Professor Adjunto da Universidade federal do Piauí.

Rogério Paes Sousa, Universidade Federal do Piauí

mestre em Zootecnia pela Universidade federal do Piauí

Karina Rodrigues Santos, Universidade Federal do Piauí

Doutora, Professora da Universidade Federal do Piauí

Luanna Chácara Pires, Universidade federal do sudeste da Bahia

Doutora, professora da Universidade federal do sudeste da Bahia

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Published

2019-05-24

How to Cite

SOUSA JUNIOR, S. C.; SOUSA, R. P.; SANTOS, K. R.; PIRES, L. C. USE OF RANDOM REGRESSION MODELS FOR ESTIMATION OF GENETIC PARAMETERS IN TABAPUÃ CATTLE. Brazilian Animal Science/ Ciência Animal Brasileira, Goiânia, v. 20, p. 1–14, 2019. Disponível em: https://revistas.ufg.br/vet/article/view/49928. Acesso em: 27 jul. 2024.

Issue

Vol. 20 (2019): Continuous publication

Section

ZOOTECNIA

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