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| Peixoto,Maria Gabriela Campolina Diniz; Santos,Daniel Jordan de Abreu; Borquis,Rusbel Raul Aspilcueta; Bruneli,Frank Ângelo Tomita; Panetto,João Cláudio do Carmo; Tonhati,Humberto. |
| The objective of this work was to compare random regression models for the estimation of genetic parameters for Guzerat milk production, using orthogonal Legendre polynomials. Records (20,524) of test-day milk yield (TDMY) from 2,816 first-lactation Guzerat cows were used. TDMY grouped into 10-monthly classes were analyzed for additive genetic effect and for environmental and residual permanent effects (random effects), whereas the contemporary group, calving age (linear and quadratic effects) and mean lactation curve were analized as fixed effects. Trajectories for the additive genetic and permanent environmental effects were modeled by means of a covariance function employing orthogonal Legendre polynomials ranging from the second to the fifth order.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bos indicus; Covariance functions; Lactation curve; Test-day model. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2014000500372 |
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| Ribeiro,Virgínia Mara Pereira; Merlo,Fernanda Albuquerque; Gouveia,Gabriela Canabrava; Winkelstroter,Larissa Kretli; Abreu,Luíza Rodrigues Alves; Silva,Marcos Vinícius Gualberto Barbosa da; Panetto,João Cláudio do Carmo; Paiva,Leandro de Carvalho; Cembranelli,Marcello de Aguiar Rodrigues; Toral,Fabio Luiz Buranelo. |
| Abstract: The objective of this work was to determine whether the random regression model using linear splines (RRMLS) is suitable to estimate the genetic parameters for productive and reproductive traits of a multiple-breed dairy cattle population, as well as to investigate the effect of the genetic group of the progeny on the genetic merit of the sire. The multiple-trait model (MTM) and the RRMLS with one knot fitted for every genetic group were used to obtain the genetic parameters. Records of 1/2 Holstein + 1/2 Gyr (1/2HG), 5/8 Holstein + 3/8 Gyr (5/8HG), and 3/4 Holstein + 1/4 Gyr (3/4HG) crossbreed dams were considered. The RRMLS showed better fitting. The additive and residual variances estimated by the MTM and the RRMLS were similar. Heritability... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gyr; Heritability; Heterosis; Holstein; Selection. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2017001101109 |
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