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Beneficios da integracao entre lavoura e pecuaria. Infoteca-e
VILELA, L.; BARCELLOS, A. de O.; SOUSA, D. M. G. de.
bitstream/CPAC-2010/23704/1/doc-42.pdf
Tipo: Documentos (INFOTECA-E) Palavras-chave: PVPECL100; Gibbs sampling; Variance components; Brasil; Bovino: Genetica e melhoramento animal.; Bovino; Cerrado; Grão; Lavoura; Pecuária; Produtividade.; Produção Animal; Genetics..
Ano: 2001 URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/567050
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Confidence intervals for the variance component of random-effects linear models AgEcon
Bottai, Matteo; Orsini, Nicola.
We present the postestimation command xtvc to provide confidence intervals for the variance components of random-effects linear regression models. This command must be used after xtreg with option mle. Confidence intervals are based on the inversion of a score-based test (Bottai 2003).
Tipo: Journal Article Palavras-chave: Xtvc; Variance components; Confidence intervals; Score test; Random-effects linear models; Research Methods/ Statistical Methods.
Ano: 2004 URL: http://purl.umn.edu/116270
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Efeito do tamanho amostral na estimativa da herdabilidade em espécies perenes. Repositório Alice
RESENDE, M. D. V. de; MORA, A. L.; HIGA, A. R.; PALUDZYSZYN FILHO, E..
Publicado em 2000.
Tipo: Artigo de periódico Palavras-chave: Acacia-negra; Predição de valores genéticos; Componente de variância; DFREML/BLUP; Black wattle; Genetic parameters; Breeding values prediction; Variance components; Parâmetro Genético.
Ano: 1998 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/288756
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Eggshell Qualities as Indicative of Eggshell Strength for Layer Selection Rev. Bras. Ciênc. Avic.
Kibala,L; Rozempolska-Rucinska,I; Kasperek,K; Zieba,G; Lukaszewicz,M.
ABSTRACT The study aimed at investigating which of four traits is the most representative of eggshell strength (destructive eggshell thickness measurement, eggshell weight, egg specific gravity, ultrasonic measurement of eggshell thickness) and could be used for selection purposes. To date, investigations focused mostly on pairwise (eggshell strength vs. another eggshell feature) analyses, resulting in two-, maybe three-trait, models when eggshell traits are considered. Since the covariance estimates are also model dependent, we collected five eggshell traits within one analysis, which better reflects what occurs in nature. The eggs were collected from 4571 Rhode Island White and 2426 Rhode Island Red hens. A multiple-trait animal model and the REML method...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Variance components; Selection criterion; Trait choice..
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2018000100099
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Estimating variance components in Stata AgEcon
Marchenko, Yulia V..
This article gives a brief overview of the popular methods for estimating variance components in linear models and describes several ways to obtain such estimates in Stata for various experimental designs. The article’s emphasis is on using xtmixed to estimate variance components. Prior to Stata 9, loneway could be used to estimate variance components for one-way random-effects models. For other experimental designs, variance components could be computed manually using saved results after anova. The latter approach is viable but requires tedious computations for complicated experimental designs. Instead, as of Stata 9, variance components are easily obtained by using xtmixed.
Tipo: Journal Article Palavras-chave: Variance components; Experimental design; ANOVA; REML; ML; Multilevel; Random coefficients; Mixed models; Research Methods/ Statistical Methods.
Ano: 2005 URL: http://purl.umn.edu/117553
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Estimation of genetic parameters in the analysis of square lattice experiment group Bragantia
VIANA,JOSÉ MARCELO SORIANO; REGAZZI,ADAIR JOSÉ.
Aiming to demonstrate how to obtain unbiased estimates of genetic parameters of base populations, unaffected by genotype x environment effects, this paper presents the variance and covariance components of the intra-block analysis of a group of square lattice experiments and the estimators of the components associated to treatment effect. Random model and mixed models with environment effect fixed and other effects random are considered. In the analysis with treatments not corrected for blocks/replications/environments, the estimators of the variance and covariance components due to treatment effect are different from those of the analysis considering the complete block model. Data from two experiments of a breeding program of Eucalyptus pyrocarpa were...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Quantitative genetics; Genetic parameters; Variance components; Covariance components; Joint analysis; Square lattice.
Ano: 1999 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051999000100019
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Estimation of genetic parameters in the square lattice analysis Bragantia
VIANA,JOSÉ MARCELO SORIANO; REGAZZI,ADAIR JOSÉ.
This paper shows how to obtain unbiased estimates of genetic parameters of base populations, e.g., genotypic variance among families, heritability on a family mean basis, genotypic correlation and direct and indirect expected genetic gains, when the sampled families were evaluated in square lattice experiment. The theoretical part presents the variance and covariance components of the intra-block analysis of square lattice and the estimators of the components associated to treatment effect, considering the ordinary least squares method. In the analysis with treatments not corrected for blocks/replications, the estimator of the component due to treatment effect is equal to that of the analysis considering the complete block model. Experimental data from a...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Quantitative genetics; Genetic parameters; Variance components; Covariance components; Square lattice.
Ano: 1999 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051999000100018
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Estimativas de parâmetros genéticos de características múltiplas através do método simples de Henderson. Repositório Alice
FREITAS, A. R. de; PEGORIN, M. J.; ALENCAR, M. M. de; FAVORETTI, A. de C..
Tipo: Artigo de periódico Palavras-chave: Componentes de variância; Touros; Dados perdidos; Matrizes; Variance components; Sire; Missing records; Matrices.; Desmama.; Weaning..
Ano: 1995 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/43279
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Genetic parameters and genetic and phenotypic trends of performance traits of equines from the Brazilian Army R. Bras. Zootec.
Dornelles,Mariana de Almeida; Araújo,Ronyere Olegário de; Everling,Dionéia Magda; Weber,Tomás; Lopes,Jader Silva; Pacheco,Paulo Santana; Breda,Fernanda Cristina; Rorato,Paulo Roberto Nogara.
The objective of this research was to compare the magnitude of genetic parameters (coefficients of heritability and genetic correlation) as estimated by the Restricted Maximum Likelihood (REML) method and Bayesian Inference, and to estimate the genetic and phenotypic trends to the traits height at the withers (HW24) and weight at 24 months of age (W24). The average heritability estimated by Bayesian Inference to HW24 was 0.47, and it was lower than that obtained by REML bi-trait analysis (0.52); however, the value estimated to W24 (0.39) was higher than that obtained by REML bi-trait analysis (0.38). The genetic correlation estimate between W24 and HW24 traits obtained by the REML method (0.66) was lower than that obtained by the Bayesian Inference Method...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Genetic correlation; Genetic progress; Variance components.
Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982012000600015
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Genetic parameters for egg production in meat quails through partial periods Ciência Rural
Ribeiro,Jeferson Corrêa; Silva,Luciano Pinheiro da; Soares,Aline Camporez Crispim; Caetano,Giovani da Costa; Leite,Carla Daniela Suguimoto; Bonafé,Cristina Moreira; Sousa,Mariele Freitas; Torres,Robledo de Almeida.
ABSTRACT: We estimated genetic and phenotypic parameters for egg production in meat-type quails aiming to propose an optimal age for selection through partial record egg production. Data of 3,503 female quails from two strains (namely, UFV1, with 1,811 and UFV2 with 1,692 females) were used. Egg production was assessed by the number of eggs recorded after 42 days of age and each partial period consisted on 35 days of egg production forward. Covariance components were estimated by using single and bivariate animal model, comprising each partial period of egg production and full egg production period (one year of egg laying). Regarding strain UFV1, heritability estimates ranges from 0.03 to 0.16, and for strain UFV2 0.20 to 0.25. The highest genetic...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Coturnix coturnix; Genetic correlation; Genetic evaluation; Heritability; Variance components.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782017000400653
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Genetic variability during four cycles of recurrent selection in rice PAB
Morais Júnior,Odilon Peixoto de; Melo,Patrícia Guimarães Santos; Morais,Orlando Peixoto de; Colombari Filho,José Manoel.
Abstract: The objective of this work was to estimate genetic and phenotypic parameters among progenies of the CNA6 population of upland rice (Oryza sativa) for grain yield and plant height in four cycles of recurrent selection, in order to evaluate the genetic variability and the genotype × location interaction. The experimental data were obtained from yield trials of S0:2 progenies, which were carried out in the experimental design of Federer’s augmented blocks, without replications for progenies within each location. The effect of S0:2 progenies was significant in all cycles for grain yield and in the first three cycles for plant height, indicating the maintenance of the population’s genetic potential to generate transgressive progenies. The...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Oryza sativa; Genotype × environment interaction; Population improvement; Quantitative genetics; Variance components.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2017001101033
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Implementacao da amostragem de Gibbs para estimacao de componentes de co-variancia e parametros geneticos em dados de campo de bovinos Nelore. Infoteca-e
MAGNABOSCO, C. de U.; FARIA, C. U. de; BORJAS, A. de los R.; LOBO, R. B.; SAINZ, R. D..
bitstream/CPAC-2010/23701/1/doc-37.pdf
Tipo: Documentos (INFOTECA-E) Palavras-chave: Gibbs sampling; Variance components; Brasil; Bovino: Genetica e melhoramento animal.; Bovino; Cerrado; Gado de Corte; Genética Animal; Gado Nelore; Parâmetro Genético.; Genetics..
Ano: 2001 URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/567054
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Industry, firm, year, and country effects on profitability: Evidence from a large sample of EU food processing firms AgEcon
Schiefer, Jan; Hartmann, Monika.
This paper analyzes the variance in accounting profitability within the European food industry. Based on a large panel data set, the variance in return on assets (ROA) is decomposed into year, country, industry, and firm effects. Further on, we include all possible interactions between year, country, and industry and discuss the theoretical foundations for these effects. After singling out the significant effect classes in a nested ANOVA with a thoroughly designed rotation regarding the order of effect introduction, we determine effect magnitude using components of variance (COV). Our results show that firm characteristics seem to be far more important than industry structure in determining the level of economic return within the food industry. Year and...
Tipo: Conference Paper or Presentation Palavras-chave: Variance components; Abnormal profit; EU-27; MBV; RBV; Comparative advantage; Agribusiness; Agricultural Finance; Financial Economics; Industrial Organization; Marketing.
Ano: 2009 URL: http://purl.umn.edu/49322
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Influence of genotype-environment interaction on the classification of Nellore bulls in Southern Brazil Animal Sciences
Bresolin, Tiago; Everling, Dionéia Magda; Rorato, Paulo Roberto Nogara; Braz, Camila Urbano; Breda, Fernanda Cristina.
The aim of this study was to assess the occurrence of genotype-environment interaction, as well as its effects on the magnitude of genetic parameters and the classification of Nellore breeding bulls for the trait adjusted weight at 205 days (W205) on Southern Brazil. The components of (co)variance were estimated by Bayesian inference, using a linear-linear animal model in a bi-trait analysis. The proposed model for the analyses considers as random the direct additive genetic and maternal effects and residual effects, and as fixed effects the contemporary groups, sex, season of birth and weighing, and calving age as covariable  (linear and quadratic effects). The a posteriori mean estimates of the direct heritabilities for W205 in the three States varied...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Beef cattle; Variance components; Genetic correlation; Bayesian inference; Genetic parameters..
Ano: 2015 URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/23602
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Interação genótipo-ambiente na produção de leite de vacas da raça Holandesa - DOI: 10.4025/actascianimsci.v30i2.4706 Animal Sciences
Falcão, Alencariano José da Silva; UFT; Martins, Elias Nunes; UEM; Costa, Cláudio Napolis; EMBRAPA; Mazucheli, Josmar; UEM.
Os efeitos, sobre a avaliação genética da interação reprodutor-região, foram investigados analisando-se 108.702 registros de produção de leite (PL305) de vacas da raça Holandesa, pertencentes a rebanhos de Minas Gerais, São Paulo, Paraná, Sanata Catarina e Rio Grande do Sul. Um modelo animal multicarácter foi aplicado para estimar os componentes de variância e covariância utilizando amostragem de Gibbs. As médias a posteriori da variância genética de Santa Catarina e Rio Grande do Sul foram superiores (p < 0,001) às estimadas nos demais estados e iguais (p > 0,05) entre si. As herdabilidades variaram entre 0,24 e 0,38. As correlações genéticas entre os estados foram de baixa magnitude e variaram entre 0,07 a 0,33. Os valores de correlação de Spearman...
Palavras-chave: 5.05.04.00-2 Reprodução Animal cadeia de Markov; Correlação; Componentes de variância; Herdabilidade. Markov chain; Correlation; Variance components; Heritability.
Ano: 2008 URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/4706
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Métodos de estimação de variâncias e parâmetros afins de características de crescimento em bovinos. Repositório Alice
FREITAS, A. R. de; VENCOVSKY, R..
Métodos interativo simples de Henderson (IHSM), maximum Verossimilhanc(ML) e o da Verossimilhança restrita (REML) de estimação de variância e parâmetros afins de características de crescimento em bovinos
Tipo: Artigo de periódico Palavras-chave: Componentes de variância; Métodos de Henderson; Variance components; Herderson Methods.; Gado de Corte.; Beef cattle..
Ano: 1993 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/42486
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Predição de valores genéticos utilizando inferência bayesiana e frequentista em dados simulados - doi: 10.4025/actascianimsci.v32i3.7862 Animal Sciences
Carneiro Júnior, José Marques; Embrapa Acre; Assis, Giselle Mariano Lessa de; Embrapa Acre; Euclydes, Ricardo Frederico; Universidade Federal de Viçosa; Martins, Williane Maria de Oliveira; Embrapa Acre; Wolter, Priscila Ferreira; Embrapa Acre.
Dados simulados foram utilizados para comparar as metodologias Eblup e Bayesiana, em dados com homogeneidade de variâncias, heterogeneidade de variância genética e heterogeneidade de variância genética e ambiental. Para obtenção dessas estruturas foram feitos descartes estratégicos dos valores genéticos aditivos e ambientais de acordo com o tipo de heterogeneidade e o nível de variabilidade desejada (alta, média ou baixa), sendo utilizados dois tamanhos de população (grande e pequena). Para a metodologia Bayesiana foram utilizados três níveis de informação a priori: não informativo, pouco informativo e informativo. A presença da heterogeneidade de variâncias causa problemas para a seleção dos melhores indivíduos, principalmente se a heterogeneidade estiver...
Tipo: Simulação de dados Palavras-chave: 5.04.02.00-5 heterogeneidade de variâncias; Componentes de variância; Simulação; Informação a priori Genética e Melhoramento dos Animais Domésticos heterogeneity of variance; Variance components; Simulation; Priori information.
Ano: 2010 URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/7862
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Sample size for full-sib family evaluation in sugarcane PAB
Leite,Mauro Sergio de Oliveira; Peternelli,Luiz Alexandre; Barbosa,Márcio Henrique Pereira; Cecon,Paulo Roberto; Cruz,Cosme Damião.
The objective of this study was to determine the minimum number of plants per plot that must be sampled in experiments with sugarcane (Saccharum officinarum) full-sib families in order to provide an effective estimation of genetic and phenotypic parameters of yield-related traits. The data were collected in a randomized complete block design with 18 sugarcane full-sib families and 6 replicates, with 20 plants per plot. The sample size was determined using resampling techniques with replacement, followed by an estimation of genetic and phenotypic parameters. Sample-size estimates varied according to the evaluated parameter and trait. The resampling method permits an efficient comparison of the sample-size effects on the estimation of genetic and phenotypic...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Saccharum officinarum; Cane breeding; Simulation; Statistical methods; Variance components.
Ano: 2009 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009001200002
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Software Selegen-REML/BLUP: a useful tool for plant breeding. Repositório Alice
RESENDE, M. D. V. de.
The software Selegen-REML/BLUP uses mixed models, and was developed to optimize the routine of plant breeding programs. It addresses the following plants categories: allogamous, automagous, of mixed mating system, and of clonal propagation. It considers several experimental designs, mating designs, genotype x environment interaction, experiments repeated over sites, repeated measures, progenies belonging to several populations, among other factors. The software adjusts effects, estimates variance components, genetic additive, dominance and genotypic values of individuals, genetic gain with selection, effective population size, and other parameters of interest to plant breeding. It allows testing the significance of the effects by means of likelihood ratio...
Tipo: Artigo de periódico Palavras-chave: Melhoramento genético; Modelos mixtos lineares; BLUP; REML; Variance components; Selection; Linear mixed models; Plant breeding.
Ano: 2016 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1061068
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Variance components of corn hybrids evaluated in the USA corn belt Agrociencia
Coutiño-Estrada,Bulmaro; Vidal-Martínez,Victor A..
Abstract In the final steps of a corn (Zea mays L.) breeding program, the test of the superior crosses is a standard practice involving yield trials in many test environments. The objectives of this research were to compare both the magnitude of the standard error of prediction of three different linear mixed models where location and hybrid effects were considered random or fixed effects and the magnitude of the phenotypic variance. Mixed, GLM, and Varcomp procedures from SAS were applied to grain yield and moisture data obtained from 40 hybrids evaluated at 22 locations within the U.S. Corn Belt. Results showed that when using a linear model which considers both location and hybrid effects as random effects, rather than fixed effects, standard errors of...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Zea mays L.; Corn hybrid; Grain moisture; Grain yield; Variance components.
Ano: 2006 URL: http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-31952006000100089
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