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Registros recuperados: 61 | |
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Fraga,Angelina Bossi; Alencar,Maurício Mello de; Figueiredo,Leopoldo Andrade de; Razook,Alexander George; Cyrillo,Joslaine Noely dos Santos Gonçalves. |
The objective of this study was to evaluate environmental factors that affect infestation of Caracu cattle breed by horn fly (Haematobia irritans) and to estimate genetic parameters for level of infestation. Infestation was evaluated on females from two herds in two consecutive years. Total number of flies on animals (FC) was counted, an infestation score (FS: 1 to 5) was recorded according to the estimated number of flies on animals, and number of parasites in photographs (FF) taken when the animals were evaluated was also counted. On each animal from one to eight observations were taken. A total of 3,836, 2,751 and 3,754 records from 718 animals were obtained for FC, FF and FS, respectively. The incidence of flies was lower during winter and higher... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Genetic correlation; Heritability; Horn fly counts; Repeatability. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000200011 |
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Regatieri,Inaê Cristina; Boligon,Arione Augusti; Albuquerque,Lucia Galvão de. |
Data from 79,884 Nellore breed animals were used to estimate genetic parameters and to evaluate the relationships among scores of conformation, precocity and musculature obtained at weaning and after yearling ages and weight of mature females. It was used the restricted maximum likelihood method in a multi-trait analysis with the model that included direct additive genetic and residual effects, as random effects, and the fixed effects of contemporary group and, as covariables, animal age at weighing and age of dam at calving (except for weight of females at adult age). Contemporary groups at weaning were defined by the variables: sex, herd, year and month of birth, and management group at birth and weaning. For definition of contemporary group at yearling,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Beef cattle; Conformation; Genetic correlation; Musculature; Precocity. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011000100014 |
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Zambrano,Juan Carlos; Echeverri,Julián. |
The objective of this study was to estimate the genetic, phenotypic and environmental parameters for calving interval (CI), days open (DO), number of services per conception (NSC) and conception rate (CR) in Holstein and Jersey cattle in Antioquia (Colombia). Variance and covariance component estimates were obtained by an animal model that was solved using the derivative-free restricted maximum likelihood method. The means and standard deviations for CI, DO, NSC and CR were: 430.32±77.93 days, 127.15±76.96 days, 1.58±1.03 services per conception and 79.88±28.66% in Holstein cattle, and 409.33±86.48 days, 125.62±86.09 days, 1.48±0.98 services per conception and 84.08±27.23% in Jersey cattle, respectively. The heritability estimates (standard errors) were:... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fertility; Genetic correlation; Heritability; Repeatability. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982014000300005 |
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Lopes,Rodrigo Ramos; Franke,Lucia Brandão; Souza,Cleber Henrique Lopes de; Bertoncelli,Patricia; Graminho,Larissa Arnhold; Ávila,Mariana Rockenbach de; Pereira,Emerson André; Motta,Eder Alexandre Minski da. |
ABSTRACT This study aimed to estimate the genetic parameters, genetic correlations, genetic dissimilarity, and predicted gains with the selection of interspecific apomictic Paspalum plicatulum × Paspalum guenoarum hybrids in relation to seed yield traits. Nineteen genotypes that showed increased forage yield in previous studies were planted in a randomized complete block design with ten blocks. Traits evaluated in this study were: number of tillers/plant, number of reproductive tillers/plant, number of racemes/inflorescence, number of seeds/inflorescence, weight of a thousand seeds, and seed yield. Data were analyzed using a mixed model approach. The genotypes evaluated in our study showed improvement potential in relation to high heritability (H a 2... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Clustering analysis; Genetic correlation; Genetic gains; Genetic parameters; REML/BLUP. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982019000100402 |
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Hidalgo,André Marubayashi; Martins,Elias Nunes; Santos,Alexandre Leseur dos; Quadros,Thays Cristina Oliveira de; Ton,Ana Paula Silva; Teixeira,Rafael. |
The objective of this research was to estimate genetic parameters for the traits egg weight, egg production in 189 days and age at first egg in three laying quails and one meat line of quails. Data was analyzed by Bayesian procedures using Gibbs sampling. The heritability estimates for egg weight, egg production in 189 days and age at first egg, were, respectively, for yellow line, 0.31, 0.84 and 0.53; for blue line, 0.14, 0.82 and 0.60; for red line, 0.70, 0.96 and 0.75; and for meat line, 0.73, 0.96 and 0.72. Genetic correlation between egg weight and egg production in 189 days, egg weight and day at first egg and egg production in 189 days and day at first egg were for yellow line, 0.58, -0.77 and -0.90; for blue line, 0.09, -0.01 and -0.95; for red... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Genetic correlation; Genetic variance; Heritability; Overlap probability; Quails. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011000100013 |
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Farias Neto,Austeclínio Lopes; Miranda Filho,José Branco de. |
Full-sib and selfed (S1) progenies were obtained from sub-populations of ESALQ-PB1, divergently selected for tassel size (T+ and T-) and ear height (E+ and E-), and used for estimating genetic and phenotypic correlation coefficients between traits. The analyzed traits were: EW- total ear weight (g/plant), PH- plant height (cm), EH- ear height (cm), TB- tassel branch number and TL- tassel length. The highest genetic (rG) and phenotypic (rF) correlation was observed for the combination PH x EH, as expected, with average of 0.800 and 0.778, respectively over sub-populations and locations. It is apparent that divergent selection for tassel size did not affect greatly the correlation between PH and EH in the full sib progenies, but in the inbred progenies the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zea mays; Genetic correlation; Divergent selection; Tassel size; Ear height. |
Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162001000100018 |
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三浦, 伸也; 鈴木, 三義. |
(社)北海道酪農検定検査協会の検定日記録および(社)日本ホルスタイン登録協会北海道支局の体型記録を用い,体細胞スコアと泌乳形質および体型形質との遺伝相関を推定した.各体型形質の記録数は審査開始時期の違いにより異なるが,多くの形質に共通な記録数を示すと,初産が181,291記録であり,2産が104,105記録,3産が30,973記録であった.遺伝相関の推定には,2形質分析モデルを用いた.母数効果としては,体細胞に対して,牛群・検定日,分娩月齢,分娩後日数の1次の回帰,分娩後日数に対するWilminkの指数項,体型形質に対しては,牛群・審査日,審査時月齢,泌乳ステージ,審査員の各効果を考慮し,さらに変量効果として両形質について,相加的遺伝効果と残差を含むモデルを用いた.体細胞スコアと乳生産形質との遺伝相関は−0.22〜0.15と低い値が推定され,初産において正の相関,2産以降では負の相関となる傾向が示された.体型形質と体細胞スコアとの遺伝相関は,産次により値が変動し,正負の符号の逆転が認められた.これは,加齢による体型変化に起因していると考えられる.体型形質の中で,乳房の深さ(−0.29〜−0.19)および前乳房の付着(−0.25〜−0.07)において,負の遺伝相関が推定された.これらの体型形質は生涯生産性,在群期間とも遺伝的な関連があり,これらの体型形質を改良することにより,体細胞スコアを低減することが可能であり,結果として生涯生産量の増加が期待できる. |
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Palavras-chave: Somatic cell score; Genetic correlation; Type trait; Milk production; Holstein. |
Ano: 2005 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2597 |
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Ribeiro,Jeferson Corrêa; Silva,Luciano Pinheiro da; Sousa,Mariele Freitas; Leite,Carla Daniela Suguimoto; Bonafé,Cristina Moreira; Caetano,Giovani da Costa; Crispim,Aline Camporez; Torres,Robledo de Almeida. |
The objective of this study was to obtain estimates of genetic and phenotypic parameters for egg mass of meat quails and also to propose an optimal age for selection of birds through the egg mass. The data used in this study came from 3,503 female meat quails (UFV1: 1.811 quails; UFV2: 1.692 quails) of the Poultry Breeding Program from Universidade Federal de Viçosa. The traits examined were egg mass in partial periods until 77, 112, 147 and 182 days, and egg mass in the total period of 407 days by the use of single and bi-trait animal models. For the genetic group UFV1, the heritability values for the periods were high: 0.58, 0.59, 0.57, 0.59 and 0.24 (until 77, 112, 147,182 and 407 days, respectively). The values of genetic correlations were medium,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Animal model; Coturnix coturnix; Egg weight; Genetic correlation; Heritability; Relative efficiency. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982012000500012 |
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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 |
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Vieira,Jairo V; Silva,Giovani Olegario da; Boiteux,Leonardo S. |
The estimate of the genetic parameters associated with processing (fresh-cut) traits, including root length (RL), is crucial for carrot breeding programs in tropical areas. The cultivar Alvorada is an important germplasm due to its resistance to nematodes, leaf blight, heat-tolerance, and high carotenoid content. Seventy-four 'Alvorada' half-sib progenies were evaluated during the summer of 2005 in the Federal District, Brazil, in a randomized complete block design with three replications. Thirteen competitive plants in each block were randomly selected and evaluated and/or classified for RL and for number of leaves (NL), leaf length (LL), root tip type (RT), root mass (RW), crown shape (CS), root diameter (RD), and xylem diameter (XD). The Pearson's... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Daucus carota; Heritability; Genetic correlation; Path analysis; Root length. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362012000100002 |
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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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Boligon,Arione Augusti; Baldi,Fernando; Albuquerque,Lucia Galvão de. |
Records from 106,212 Nellore animals, born between 1998 and 2006, were used to estimate (co)variance components and genetic parameters for birth weight (BW), average weight gains from birth to weaning (GBW), average weight gains from weaning to after yearling (GWAY), weaning hip height (WHH), postweaning hip height (PHH) and scrotal circumferences at 9 (SC9), 12 (SC12) and 15 (SC15) months of age. (Co)variance components were estimated by an animal model using multi-trait analysis. Heritability estimates for BW, GBW, GWAY, WHH, PHH, SC9, SC12 and SC15 were 0.31 ± 0.01; 0.25 ± 0.02; 0.30 ± 0.04; 0.51 ± 0.04; 0.54 ± 0.04; 0.39 ± 0.01; 0.41 ± 0.01 and 0.44 ± 0.02, respectively. Genetic correlations between growth traits ranged from 0.09 ± 0.01 to 0.88 ± 0.01,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Beef cattle; Genetic correlation; Hip height; Average weight gain. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000200010 |
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Reis Neto,Rafael Vilhena; Oliveira,Carlos Antônio Lopes de; Ribeiro,Ricardo Pereira; Freitas,Rilke Tadeu Fonseca de; Allaman,Ivan Bezerra; Oliveira,Sheila Nogueira de. |
The main factor considered in breeding programs for fish is growth, which can be assessed in terms of a gain in either weight or body measurements. This study was undertaken to evaluate the morphometric traits of GIFT strain tilapia (Oreochromis sp.) selected for weight gain. The data set used contained information on 6,650 animals. The genetic values of 8,590 animals in a relationship matrix of five generations were predicted. The following morphometric measurements were evaluated: standard length; body depth and body width. Body area and volume were also calculated. Bi-character analyses involving morphometric traits were used to estimate (co)variance components. Heritability, larval and fingerling common environmental effects were estimated for each... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bayesian approach; Genetic correlation; Genetic gain; Heritability. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162014000400001 |
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Nunes,Beatriz do Nascimento; Ramos,Salvador Boccaletti; Savegnago,Rodrigo Pelicioni; Ledur,Mônica Corrêa; Nones,Kátia; Klein,Claudete Hara; Munari,Danísio Prado. |
The objective of this study was to estimate genetic and phenotypic correlations of body weight at 6 weeks of age (BW6), as well as final carcass yield, and moisture, protein, fat and ash contents, using data from 3,422 F2 chickens originated from reciprocal cross between a broiler and a layer line. Variance components were estimated by the REML method, using animal models for evaluating random additive genetic and fixed contemporary group (sex, hatch and genetic group) effects. The heritability estimates (h²) for BW6, carcass yield and percentage of carcass moisture were 0.31 ± 0.07, 0.20 ± 0.05 and 0.33 ± 0.07, respectively. The h² for the percentages of protein, fat and ash on a dry matter basis were 0.48 ± 0.09, 0.55 ± 0.10 and 0.36 ± 0.08,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Broiler; Carcass composition; Genetic correlation. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000300011 |
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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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Lôbo,Ana Maria Bezerra Oliveira; Lôbo,Raimundo Nonato Braga; Paiva,Samuel Rezende; Oliveira,Sônia Maria Pinheiro de; Facó,Olivardo. |
The genetic parameters for growth, reproductive and maternal traits in a multibreed meat sheep population were estimated by applying the Average Information Restricted Maximum Likelihood method to an animal model. Data from a flock supported by the Programa de Melhoramento Genético de Caprinos e Ovinos de Corte (GENECOC) were used. The traits studied included birth weight (BW), weaning weight (WW), slaughter weight (SW), yearling weight (YW), weight gain from birth to weaning (GBW), weight gain from weaning to slaughter (GWS), weight gain from weaning to yearling (GWY), age at first lambing (AFL), lambing interval (LI), gestation length (GL), lambing date (LD - number of days between the start of breeding season and lambing), litter weight at birth (LWB)... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Age at first lambing; Genetic correlation; Heritability; Body weight; Litter weight. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000400016 |
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Sabedot,Mayara Andressa; Romano,Gabrieli de Souza; Pedrosa,Victor Breno; Pinto,Luís Fernando Batista. |
ABSTRACT This study aimed to estimate the heritability of milk yield (MY), fat percent (F%), fat yield (FY), protein percent (P%), protein yield (PY), somatic cell score (SCS), and total bacterial count score (TBCS) as well as to estimate the genetic correlations among these traits, using a dataset from 5,918 lactations of Jersey cows in Brazil. The covariance components were estimated by restricted maximum likelihood using the PEST and VCE6 programs. The average values obtained for MY, F%, FY, P%, PY, SCS, and TBCS were 5017.5 kg, 4.3%, 192.3 kg, 3.3%, 173.0 kg, 5.9, and 2.9, respectively, while the heritability values were 0.16, 0.55, 0.18, 0.61, 0.25, 0.21, and 0.08, respectively. The genetic correlations ranged from low to high magnitude, with positive... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Genetic correlation; Heritability; Mastitis resistance; Selection. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982018000100408 |
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Malhado,Carlos Henrique Mendes; Malhado,Ana Claudia Mendes; Ramos,Alcides de Amorim; Carneiro,Paulo Luiz Souza; Souza,Julio César de; Pala,Akin. |
The major objective of this study was to estimate heritability and genetic correlations between milk yield (MY) and calving interval (CI) and lactation length (LL) in Murrah buffaloes using Bayesian inference. The database used belongs to the genetic improvement program of four buffalo herds from Brazil. To obtain the estimates of variance and covariance, bivariate analyses were performed with the Gibbs sampler, using the program MTGSAM. The heritability coefficient estimates were 0.28, 0.03 and 0.15 for MY, CI and LL, respectively. The genetic correlations between MY and LL was moderate (0.48). However, the genetic correlation between MY and CI showed large HPD regions (highest posterior density interval). Milk yield was the only trait with clear... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Genetic correlation; Gibbs sampler; Heritability. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013000800005 |
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Registros recuperados: 61 | |
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