Comparison of Methods of Predicting Breeding Values of Swine

Keele, J. W.; Johnson, R. K.; Young, L. D.; Socha, T. E.

doi:10.2527/jas1988.66123040x

Cited by 22 publications

(13 citation statements)

References 13 publications

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“…A metodologia de modelos mistos para avaliação genética de suínos tem sido empregada e recomendada por vários pesquisadores em melhoramento animal (SORENSEN e KENNEDY, 1986;KEELE et al, 1988;LOPES, 1994a;MARTINS, 1995;e TORRES JR., 1996) e indicada por fornecer predições não-viesadas de efeitos genéticos, efeitos comuns ou permanentes de ambiente e de grupo de animais, efeitos maternos e de endogamia, e efeitos de seleção, entre outros.…”

Section: Pires Et Al Modelos Lineares Mistos E Dados Desbalanceadosunclassified

Estimação de parâmetros genéticos de características reprodutivas em suínos

Pires¹,

Lopes²,

Torres³

et al. 2000

R. Bras. Zootec.

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RESUMO -Com o objetivo de estimar os parâmetros genéticos e fenotípicos de características reprodutivas de suínos, foram utilizados dados de peso da leitegada ao nascimento (PLN), peso da leitegada ajustado para 21 dias (PL21), tamanho de leitegada ao nascimento (TLN), tamanho de leitegada ao desmame (TLD) e taxa de mortalidade (TM), de três raças de suínos, Duroc, Landrace e Large White. Variâncias e covariâncias genéticas e fenotípicas foram estimadas pelo Método da Máxima Verossimilhança Restrita (REML), usando modelo que inclui os efeitos genéticos direto e materno e comum de leitegada. Estes componentes foram usados para calcular as herdabilidades direta ( 2 d h ), materna ( 2 m h ) e total ( 2 T h ), o efeito comum de leitegada (c 2 ) e as correlações genéticas e fenotípicas. As herdabilidades direta, materna e total apresentaram valores baixos a médios: 0,00 a 0,17, 0,00 a 0,14 e 0,00 a 0,15, respectivamente, destacando a importância da seleção com base nas informações de parentes para o melhoramento genético destas características. As correlações entre os efeitos genéticos aditivos direto e materno foram, de modo geral, altas e negativas, evidenciando antagonismo entre estes efeitos. As estimativas de c 2 foram em geral baixas para todas as características. As correlações genéticas entre PLN, PL21, TLN e TLD tenderam a ser altas e positivas, e as correlações entre estas características e TM apresentaram-se ora positivas, ora negativas.Palavras-chave: efeito materno, leitegada, modelo animal, REML, suíno Genetic Parameters Estimation on Swine Reproductive TraitsABSTRACT -With the objective to estimate genetic and phenotypic parameters of swine reproductive traits, litter weight at birth (PLN), litter weight at 21 days (PL21), litter size at birth (TLN), litter size at weaning (TLD) and mortality rate (TM) data of three swine breeds, Duroc, Landrace and Large White were used. The genetic and phenotypic (co)variances were estimated by Restricted Maximum Likelihood (REML) method. These components were used to estimate the direct ( h ) heritabilities, the common litter effect (c 2 ), and the genetic and phenotypic correlations. The direct, maternal and total heritability estimates were small to medium, 0.00 to 0.17, 0.00 to 0.14 and 0.00 to 0.15, respectively, indicating the necessity to include information on relatives in selection programs to improve these traits. The correlations among the additive direct and maternal genetic effects were, in general, high and negative, evidencing antagonism among these effects. The estimates of c2 were, in general, low, for all traits and breeds. The genetic correlations among PLN, PL21, TLN and TLD tended to be high and positive, and the correlations between these traits and TM were positive in some cases, and negative in others.Key Words: animal model, litter, maternal effects, REML, swine Rev. bras. zootec., 29(6):1698-1705, 2000 Introdução O conhecimento das propriedades genéticas das populações baseia-se em parâmetros genéticos que podem ser obtidos utilizando-se ...

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Section: Pires Et Al Modelos Lineares Mistos E Dados Desbalanceadosunclassified

Estimação de parâmetros genéticos de características reprodutivas em suínos

Pires¹,

Lopes²,

Torres³

et al. 2000

R. Bras. Zootec.

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“…In pigs, numerous studies have been conducted to evaluate the advantage of using BLUP instead of standard selection indexes in a variety of situations (Belonsky and Kennedy, 1988;Keele et al, 1988;Sorensen, 1988; Wray, 1989;Long et al, 1990; De Vries et al, 1990;Roehe et al, 1990). National genetic evaluation programmes based on the BLUP-IAM technique have been implemented in several countries since 1985 (Hudson and Kennedy, 1985;Van Hofstraeten and Vandepitte, 1988;Harris et al, 1989; Sorensen and Vernessen, 1991).…”

Section: Introductionmentioning

confidence: 99%

Multivariate restricted maximum likelihood estimation of genetic parameters for growth, carcass and meat quality traits in French Large White and French Landrace pigs

Ducos¹,

Bidanel²,

Ducrocq³

et al. 1993

Genet. Sel. Evol.

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Summary -Genetic parameters of 7 traits measured in central test stations -average daily gain (ADG1), feed conversion ratio (FCR) and backfat thickness (ABT) measured on candidates for selection, and average daily gain (ADG2), dressing percentage (DP), estimated carcass lean content (ECLC) and meat quality index (MQI) 0,30; 0,6/,; 0,22; 0,52; 0,39; 0,60; 0,33 en race LW et 0,3l,; 0,56; 0,25; 0,l!6; 0,31; 0,68; 0,23

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“…But, several recent studies (Belonsky and Kennedy, 1988;Keele et al, 1988) have indicated that even with high heritability, BLUP results in greater accuracy of evaluation than selection on phenotype or index. Keele et al (1988) also concluded that BLUP is robust to errors in estimated heritability.…”

Section: Ties Across Testsmentioning

confidence: 99%

“…In recent years, results of mixedmodel analyses of swine data have been reported with increasing frequency Mabry et al, 1987;Keele et al, 1988). Most research on mixed-model methodology has been conducted using design structures commonly found in cattle data.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of performance-tested boars using a single-trait animal model.

Wood

Christian²,

Rothschild³

1991

Journal of Animal Science

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Data structure designs for breeding value estimation of performance-tested boars using mixed-model methodology were compared. Computer models were based on estimates of parameters from the literature and from results of a survey of test station managers. Results were compared using accuracy (the correlation of true and estimated breeding values) and prediction error variance (PEV). The single-trait animal model included a fixed effect due to station-season, a random effect due to breeding value for ADG or backfat, and a random error term. Family size, number of families per test, and relationships among animals within and across tests were varied. Prediction error variance decreased faster for small families than for large ones as number of families increased, but increasing numbers of animals per pen was most important, especially if test size was optimized. With no other genetic ties, full-sibs were much more accurately evaluated than half-sibs. Designs that included sire ties among families within a station-season resulted in increased PEV. Increasing the number of full-sibs and(or) increasing the number of families per test would help to optimize PEV and correct this problem. Tying station-seasons with the relationship matrix improved the average accuracy of predicted breeding values. Placing full-sibs in different stations resulted in the greatest accuracy of evaluation, but a large number of half-sib (sire) ties resulted in comparable accuracies. Half-cousin ties did not improve accuracy of evaluation but could result in significant genetic progress by increasing the selection differential. EVALUATION OF PERFORMANCE-TESTED BOARS USING A SINGLE-TRAIT ANIMAL MODEL'C. M. Wood2, L. L. Christian3 and M. F. Rothschild3Iowa State University, Ames 50011 ABSTRACTData structure designs for breeding value estimation of performancetested boars using mixed-model methodology were compared. Computer models were based on estimates of parameters from the literature and from results of a survey of test station managers. Results were compared using accuracy (the correlation of true and estimated breeding values) and prediction error variance 0. The single-trait animal model included a fixed effect due to station-season, a random effect due to b r d i g value for ADG or backfat, and a random error term. Family size, number of families per test, and relationships among animals within and across tests were varied. Prediction error variance decreased faster for small families than for large ones as number of families increased, but increasing numbers of animals per pen was most important, especially if test size was optimized. With no other genetic ties, full-sibs were much more accurately evaluated than half-sibs. Designs that included sire ties among families within a station-season resulted in increased PEV.Increasing the number of full-sibs and(or) increasing the number of families per test would help to optimize PEV and correct this problem. Tying station-seasons with the relationship matrix improved the average ac...

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Comparison of Methods of Predicting Breeding Values of Swine

Cited by 22 publications

References 13 publications

Estimação de parâmetros genéticos de características reprodutivas em suínos

Estimação de parâmetros genéticos de características reprodutivas em suínos

Multivariate restricted maximum likelihood estimation of genetic parameters for growth, carcass and meat quality traits in French Large White and French Landrace pigs

Evaluation of performance-tested boars using a single-trait animal model.

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