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| Biassus,Igor de Oliveira; Cobuci,Jaime Araújo; Costa,Claudio Napolis; Rorato,Paulo Roberto Nogara; Braccini Neto,José; Cardoso,Leandro Lunardini. |
| Total numbers of 56,508, 35,091 and 8,326 records of milk, fat, and protein test-day yields, respectively, were used to estimate genetic parameters for six persistency measures on milk, fat and protein productions of Holstein cows reared in Minas Gerais state. Covariance components for additive genetic effects and permanent environmental effects were estimated by REML in random regression models using Legendre polynomials from the third to the sixth order. Overall, models with the highest orders of Legendre polynomials showed the best quality of adjustments of these productive records. Heritability estimates obtained by the models for persistence in milk, fat, and protein yields ranged from 0.04 to 0.32, from 0.00 to 0.23, and from 0.00 to 0.27,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Genetic correlation; Heritability; Legendre polynomials; Random regression model; Selection. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010001200009 |
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| Cardoso,Leandro Lunardini; Braccini Neto,José; Cardoso,Fernando Flores; Cobuci,Jaime Araújo; Biassus,Igor de Oliveira; Barcellos,Júlio Otávio Jardim. |
| It was evaluated statistical models with different assumptions to define the one that best describes the presence of genotype × environment interaction on adjusted post-weaning weight gain (PWG345) of Hereford cattle, through the study of reactions norms to the environment, obtained by random regression using a Bayesian approach. Four reaction norms hierarchical models (RNHM) were used through the INTERGEN program. The RNHM K uses the solutions of contemporary groups previously estimated by the standard animal model (AM) and considers them as environmental level for predicting the reaction norms and the RNHM S, which jointly estimate these two sets of unknowns. For both models, two versions were considered, one with a homogeneous (hm) and another with a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Adaptability; Bayesian inference; Environmental sensitivity; Genetic evaluation; Random regression. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011000200009 |
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| Biassus,Igor de Oliveira; Cobuci,Jaime Araújo; Costa,Claudio Napolis; Rorato,Paulo Roberto Nogara; Braccini Neto,José; Cardoso,Leandro Lunardini. |
| The objective of this study was to estimate genetic parameters for milk, fat and protein yields of Holstein cows using 56,508; 35,091 and 8,326 test-day milk records from 7,015, 4,476 and 1,114 cows, calves of 359, 246 and 90 bulls, respectively. The additive genetic and permanent environmental effects were estimated using REML. Random regression models with Legendre polynomials from order 3 to 6 were used. Residual variances were considered homogeneous over the lactation period. The estimates of variance components showed similar trends, with an increase of the polynomial order for each trait. The heritability estimates ranged from 0.14 to 0.31; 0.03 to 0.21 and 0.09 to 0.33 for milk, fat and protein yield, respectively. Genetic correlations among milk,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fat yield; Herdability; Milk yield; Protein yield; Test-day. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011000100012 |
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