Genetic parameters and trends for preweaning growth traits in the mexican Simmental population
Birth weight (18,383) and weaning weight (9,023) records from the Mexican Simmental beef cattle population were used to estimate genetic additive direct and maternal variances, heritabilities, genetic correlations, and genetic trends. Information came from 434 herds owned by members of the Mexican Simmental-Simbrah Association, and collected from 1980 to 1999. Contemporary groups were defined as herd-year-seasons. A two-trait animal model with additive direct and maternal effects was used to estimate genetic variances and genetic parameters, and to predict genetic values. Heritabilities for birth weight were 0.40 for additive direct and 0.12 for additive maternal, and the additive direct-maternal genetic correlation was -0.63. Weaning weight heritabilities were 0.33 for additive direct and 0.19 for additive maternal, and the additive direct-maternal correlation was -0.67. The only across-trait nonzero genetic correlation was between birth weight direct and weaning weight direct (0.73). Maternal heritabilities were lower than direct heritabilities, and negative correlations between additive direct and maternal effects existed for both traits. Genetic trends in the Mexican Simmental population were positive for additive direct, and negative for additive maternal genetic effects. These trends suggest that most of the selection emphasis was likely placed on additive direct genetic effects for weaning weight. Because of the negative correlation that existed between additive direct and maternal genetic effects in the Mexican Simmental population, selection programs for preweaning growth would need to strike an appropriate balance between these two types of effects.
| Main Authors: | , , , |
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| Format: | Digital revista |
| Language: | spa |
| Published: |
Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias
2012
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| Online Access: | https://cienciaspecuarias.inifap.gob.mx/index.php/Pecuarias/article/view/1419 |
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