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| Prestes,Alan Miranda; Oliveira,Mauricio Morgado de; Mello,Fernanda Cristina Breda; Rorato,Paulo Roberto Nogara; Lopes,Jader Silva; Feltes,Giovani Luis; Bravo,André Padilha. |
| Abstract: The objective of this work was to identify the most suitable model for the genetic evaluation of post-weaning weight gain in a multibreed Angus-Nelore population. Three models were tested using the Bayesian inference method: traditional animal model (M1), multibreed animal model without (M2) and with segregation (M3). The choice of the best model followed the criteria: number of parameters (Np), deviance information criterion (DIC), conditional predictive ordinate (CPO), and deviance based on Bayes factors. Spearman’s rank correlations were estimated for the top 10, 20, and 30% sires. M1 presented the highest values for all criteria, except for Np, and the lowest direct heritability estimate of 0.15±0.01. The heritability estimates for M2 and M3... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Animal breeding; Crossbreeding; Dominance; Epistatic losses; Genetic parameters. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2019000102803 |
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| Dornelles,Mariana de Almeida; Rorato,Paulo Roberto Nogara; Gama,Luis Telo Lavadinho da; Breda,Fernanda Cristina; Bondan,Carlos; Everling,Dionéia Magda; Michelotti,Vanessa Tomazetti; Feltes,Giovani Luis. |
| ABSTRACT: The objective of this study was to compare the functions of Wilmink and Ali and Schaeffer with Legendre polynomials in random regression models using heterogeneous residual variances for modeling genetic parameters during the first lactation in the Holstein Friesian breed. Five thousand eight hundred and eighty biweekly records of test-day milk production were used. The models included the fixed effects of group of contemporaries and cow age at calving as covariable. Statistical criteria indicated that the WF.33_HE2, LEG.33_HE2, and LEG.55_HE4 functions best described the changes in the variances that occur throughout lactation. Heritability estimates using WF.33_HE2 and LEG.33_HE2 models were similar, ranging from 0.31 to 0.50. The LEG.55_HE4... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ali and Schaeffer function; Classes of residual variance; Lactation curve; Legendre polynomials; Wilmink function. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016000901649 |
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| Dornelles,Mariana de Almeida; Rorato,Paulo Roberto Nogara; Breda,Fernanda Cristina; Bondan,Carlos; Gama,Luis Telo Lavadinho da; Cobuci,Jaime Araujo; Feltes,Giovani Luis; Michelotti,Vanessa Tomazetti; Prestes,Alan Miranda. |
| Objetivou-se comparar um modelo multi-característica padrão com modelos de análise de fatores (AF) e de componentes principais (CP) para estimar parâmetros genéticos para a produção de leite no dia do controle (PLDC) de vacas da raça Holandesa. O arquivo de trabalho constituiu-se de 4.616 registros mensais de PLDC de primeiras lactações de vacas da raça Holandesa. As PLDC foram agrupadas em dez classes mensais, entre o 5o e 305o dia da lactação (PLDC1 a PLDC10). Foram realizadas análises considerando 11 modelos diferentes, como segue: multi-característica padrão (MC); cinco modelos de posto reduzido, para a matriz de covariância genética, ajustando um a cinco (CP1 ... CP5) componentes principais; e dois modelos utilizando análise de fatores (F1, F2, F3, F4... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Componentes de variância; Correlações genéticas; Herdabilidade; Posto reduzido. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782015000601087 |
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| Feltes,Giovani Luis; Michelotti,Vanessa Tomazetti; Prestes,Alan Miranda; Bravo,André Padilha; Bondan,Carlos; Dornelles,Mariana de Almeida; Breda,Fernanda Cristina; Rorato,Paulo Roberto Nogara. |
| ABSTRACT: The objective of this study was to identify a nonlinear regression model that better describes the milk production and the percentages of fat and protein curves, and to identify the season and age of calving that result in higher productions. For the analysis, 8,047 records of milk production and percentages of fat and protein obtained from 1,330 Holstein breed cows raised in Rio Grande do Sul, born from 1989 to 2011, were used. After determining the most appropriate nonlinear regression model, the identity of models and the equality of parameter tests for the different classes of season and age of calving were performed. Residual mean square, mean absolute deviation, mean squared prediction error and percentage of estimated curves per animal,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calving season; Hyperbolic linear function; Age at calving; Identity model test. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016000400700 |
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