Consulta: subjectFacets:"Legendre polynomials"
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Genetic parameters for faecal egg count, packed-cell volume and body-weight in Santa Inês lambs
Provedor de dados: Genetics and Molecular Biology
Autores: Lôbo,Raimundo N.B.; Vieira,Luiz S.; Oliveira,Amaury A. de; Muniz,Evandro N.; Silva,José M. da.
Worm infection is one of the main factors responsible for economic losses in sheep breeding in Brazil. Random regression analysis was used to estimate genetic parameters for the factors faecal egg-count (FEC), packed-cell volume (PCV) and body weight (BW) in Santa Inês lambs. Data from 119 female, offspring of nine rams, were collected between December, 2005 and December, 2006, from the experimental flock of Embrapa Tabuleiros Costeiros, the Brazilian Agricultural Research Corporation located in Frei Paulo, SE, Brazil. After weaning, females were drenched until the faecal egg count had dropped to zero. Two natural challenges were undertaken. FEC heritability was extremely variable, this increasing from 0.04 to 0.27 in the first challenge and from 0.01 to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Genetic correlations; Heritability; Legendre polynomials; Random regression.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000200014

Reliability of breeding values between random regression and 305-day lactation models
Provedor de dados: Pesquisa Agropecuária Brasileira
Autores: Padilha,Alessandro Haiduck; Cobuci,Jaime Araujo; Daltro,Darlene dos Santos; Braccini Neto,José.
Abstract The objective of this work was to verify the gain in reliability of estimated breeding values (EBVs), when random regression models are applied instead of conventional 305-day lactation models, using fat and protein yield records of Brazilian Holstein cattle for future genetic evaluations. Data set contained 262,426 test-day fat and protein yield records, and 30,228 fat and protein lactation records at 305 days from first lactation. Single trait random regression models using Legendre polynomials and single trait lactation models were applied. Heritability for 305-day yield from lactation models was 0.24 (fat) and 0.17 (protein), and from random regression models was 0.20 (fat) and 0.21 (protein). Spearman correlations of EBVs, between lactation...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Breeding value; Correlation; Legendre polynomials; Reliability.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016001101848

Estimation of (co)variance components and genetic parameters for weights of red-winged tinamou using random regression models
Provedor de dados: Revista Brasileira de Zootecnia
Autores: Tholon,P.; Queiroz,S.A.
The objective of this work was to determine genetic parameters for body weight of tinamou in captivity. It was used random regression models in analyses of data by considering the direct additive genetic (DA) and permanent environmental effects of the animal (PE) as random effects. Residual variances were modeled by using a fifth-order variance function. The mean population growth curve was fitted by sixth-order Legendre orthogonal polynomials. Direct additive genetic effects and animal environmental permanent effect were modeled by using Legendre polynomials of order two to nine. The best results were obtained by models with orders of fit of 6 for direct additive genetic effect and of order 3 for permanent effect by Akaike information criterion and of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Genetic correlation; Heritability; Legendre polynomials; Tinamou; Wild bird.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011000400011

Genetic evaluation of partial growth trajectory of Santa Inês breed using random regression models
Provedor de dados: Revista Brasileira de Zootecnia
Autores: Oliveira,Kassiana Adriano Pinto de; Lôbo,Raimundo Nonato Braga; Facó,Olivardo.
It was evaluated data set of 19,303 weight records of Santa Inês sheep in order to evaluate distinct polynomial functions with different order for better adjustements of fixed and random regressions of growth trajectory and to estimate (co)variances components and genetic parameters of this trajectory. Fixed effects used in analysis were contemporary group, sex and birth type. Ordinary and Legendre polynomials, ranging from two to four orders, were evaluated for fixed regression of average growth trajectory. Legendre and quadratic b-spline functions, ranging from three to four orders, were evaluated for random regressions. Legendre polynomials of order fourth were suitable to fit random regression, while ordinary polynomials of third order were the best...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Β-spline functions; Genetic correlation; Heritability; Legendre polynomials; Ordinary polynomials.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010000500013

Persistence in milk, fat and protein production of primiparous Holstein cows by random regression models
Provedor de dados: Revista Brasileira de Zootecnia
Autores: 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

Weight evaluation of Tabapuã cattle raised in northeastern Brazil using random-regression models
Provedor de dados: Arquivo Brasileiro de Medicina Veterinária e Zootecnia
Autores: Oliveira,M.R.; Azevêdo,D.M.; Malhado,C.; Pires,L.; Martins Filho,R.; Sousa Júnior,S.
ABSTRACT The objective of this study is to compare random-regression models used to describe changes in evaluation parameters for growth in Tabapuã bovine raised in the Northeast of Brazilian. The M4532-5 random-regression model was found to be best for estimating the variation and heritability of growth characteristics in the animals evaluated. Estimates of direct additive genetic variance increased with age, while the maternal additive genetic variance demonstrated growth from birth to up to nearly 420 days of age. The genetic correlations between the first four characteristics were positive with moderate to large ranges. The greatest genetic correlation was observed between birth weight and at 240 days of age (0.82). The phenotypic correlation between...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Age; Covariance functions; Growth curve; Legendre polynomials; Livestock.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352017000200457

Random regression models using different functions to estimate genetic parameters for milk production in Holstein Friesians
Provedor de dados: Ciência Rural
Autores: 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