Estimates of genetic parameters for litter size at different parities in pigs

Alfonso, L.; Noguera, J. L.; Babot, D.; Estany, J.

doi:10.1016/s0301-6226(96)01401-7

Cited by 34 publications

(44 citation statements)

References 14 publications

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“…In some previous studies heritabilities obtained with the MT model were generally smaller than with the repeatability model (Alfonso et al, 1997;Hanenberg et al, 2001). Small additive genetic variances and consequently low heritabilities were found in this study in the first and the last parity.…”

Section: Discussioncontrasting

confidence: 64%

“…They mainly depend on genetic correlations between litter size in subsequent parities, size of data set, capacity of computing etc. Due to simplicity many pig breeding organizations use repeatability model for the estimation of breeding values for litter size (e.g., Alfonso et al, 1997;Noguera et al, 1998). A repeatability model assumes that genetic correlations between litter size in subsequent parities are equal to one and that the variance is constant along this trajectory.…”

Section: Introductionmentioning

confidence: 99%

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Genetic parameters for litter size in Black Slavonian pigs

Škorput¹,

Đikić²,

Luković³

2014

Span. j. agric. res.

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The objective of this study was to estimate genetic parameters for litter size of Black Slavonian pigs using the repeatability, multiple trait, and random regression models, and to consider the possibility to increase litter size in Black Slavonian pigs by selection. A total of 4,733 litter records from the first to the sixth parity from sows that farrowed between January 1998 and December 2010 were included in the analysis. Individual record consisted of the following variables: breeding organisation (eight regions), parity (1-6), service boar, and farrowing season (monthyear interaction). Estimation of all the covariance components with three different models was based on the residual maximum likelihood method. Estimate of additive genetic variance and heritability for number of piglets born alive with repeatability model was 0.23 and 0.10, respectively. Estimates of additive genetic variance with multiple trait and random regression model were in a wider range from 0.05 to 0.65 across parities, and heritabilities were estimated in the range between 0.03 and 0.26. Estimates of phenotypic and additive genetic correlations were much smoother with random regression model in comparison with multiple trait model. Due to unexpected changes of variances along trajectory obtained with multiple trait and random regression model, the best option for genetic evaluation of litter size for now could be the use of repeatability model. With increasing number of data with proper data structure alternative modelling of litter size of Black Slavonian pig using multiple trait and random regression model could be taken into consideration.Additional key words: number of piglets born alive; local breed; repeatability; multiple trait model; random regression model.

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Section: Discussioncontrasting

confidence: 64%

Section: Introductionmentioning

confidence: 99%

Genetic parameters for litter size in Black Slavonian pigs

Škorput¹,

Đikić²,

Luković³

2014

Span. j. agric. res.

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“…In the literature, the genetic correlation for litter size among parities generally exceeds 0.70 between the first and subsequent parities (Knap et al, 1993;Irgang et al, 1994;Roehe & Kennedy, 1995;Tholen et al, 1996;Alfonso et al, 1997;Hanenberg et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Estimation of variance components, genetic parameters and genetic trends for litter size of swines

et al. 2010

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-Records of Large White breed animals were used to estimate variance components, genetic parameters and trends for the character total number of born piglets (TNBP) as measure of litter size. For obtaining variance components and genetic parameters, it was used the Restricted Maximum Likelihood Method using MTDFREML software. Two mixed models (additive and repeatability) were evaluated. The additive model contained fixed effect of the contemporary group and the following random effects: direct additive genetic and residual effect for the first parturition. Repeatability model had the same effects of the additive model plus parturition order fixed effect and non-correlated animal permanent environment random effect for the second, third and forth parturition. Direct additive heritability estimates for TNBP were 0.15 and 0.20 for the additive and repeatability models, respectively. The estimate of the ration among variance of the non-correlated effect of animal permanent environment effect and the phenotypic variance, expressed as total variance proportion (c2) was 0.09. The estimates of yearly genetic trends obtained in the additive and repeatability models have similar behaviors (0.02 piglets/sow/year).

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“…Segundo Hanenberg et al (2001), a correlação genética para tamanho de leitegada entre parições excede 0,70, exceto em alguns casos, entre a primeira e as posteriores parições (Alfonso et al, 1997;Irgang al.,1994;Knap et al, 1993;Roehe & Kennedy, 1995;Tholen et al, 1996).…”

Section: Resultsunclassified

Estimação de parâmetros genéticos em tamanho de leitegada de suínos utilizando análises de características múltiplas

Barbosa¹,

Lopes²,

Regazzi³

et al. 2008

R. Bras. Zootec.

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RESUMO-Registros de animais da raça Large White foram utilizados para estimar componentes de co-variâncias e parâmetros genéticos para a característica número de leitões nascidos como medida do tamanho de leitegada. Na obtenção dos componentes de co-variâncias e dos parâmetros genéticos, utilizou-se o método da Máxima Verossimilhança Restrita, com o algoritmo Livre de Derivadas, por meio do programa MTDFREML. O modelo misto continha o efeito fixo de grupo contemporâneo e os efeitos aleatórios genético aditivo direto e residual. Dados das primeiras quatro parições foram usados em duas análises: análises unicaracterísticas e análise multicaracterística separada em séries de análises bicaracterísticas, na qual cada parição foi tratada como característica diferente. As estimativas de herdabilidades aditivas diretas para as parições obtidas nas análises multicaracterísticas foram consistentes com as estimativas obtidas nas análises unicaracterísticas, que variaram de 0,14 a 0,20. Estimativas de correlação fenotípica foram menores que as correlações genéticas. As correlações genéticas foram menores que 0,75 em todas as parições, exceto entre a terceira e a quarta parição, cuja correlação foi alta (0,91). A menor correlação genética foi observada entre a primeira e a segunda ordem de parto (0,60). Palavras-chave: características reprodutivas, correlação genética, herdabilidade, número de leitões nascidos, REML ABSTRACT-Data from the first four parities of Large White pigs were used to estimate (co)variance components and genetic parameters for litter size (LS) in single trait and multi-trait analyses. The (co)variance components and genetic parameters were estimated by restricted maximum likelihood using the MTDFREML program. LS in each parity was considered a different trait and the models included contemporary group as fixed effect and additive direct genetic and residual as random effects. Heritability estimates of LS in different parities in single trait analyses ranged from 0.14 to 0.20. Estimates of heritability in multi-trait analyses were similar to those obtained in single trait analyses. Phenotypic correlation estimates were lower than the genetic ones. Genetic correlations between parities were lower than 0.75, except for the estimate between the third and fourth parities, which was the highest one (0.91). The smallest genetic correlation (0.60) was observed between the first and second parities.

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Estimates of genetic parameters for litter size at different parities in pigs

Cited by 34 publications

References 14 publications

Genetic parameters for litter size in Black Slavonian pigs

Genetic parameters for litter size in Black Slavonian pigs

Estimation of variance components, genetic parameters and genetic trends for litter size of swines

Estimação de parâmetros genéticos em tamanho de leitegada de suínos utilizando análises de características múltiplas

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