A note on genetic parameters and accuracy of estimated breeding values in honey bees

Abstract Background In honey bees, observations are usually made on colonies. The phenotype of a colony is affected by the average breeding value for the worker effect of the thousands of workers in the colony (the worker group) and by the breeding value for the queen effect of the queen of the colony. Because the worker group consists of multiple individuals, interpretation of the variance components and heritabilities of phenotypes observed on the colony and of the accuracy of selection is not straightforward. The additive genetic variance among worker groups depends on the additive genetic relationship between the drone-producing queens (DPQ) that produce the drones that mate with the queen. Results Here, we clarify how the relatedness between DPQ affects phenotypic variance, heritability and accuracy of the estimated breeding values of replacement queens. Second, we use simulation to investigate the effect of assumptions about the relatedness between DPQ in the base population on estimates of genetic parameters. Relatedness between DPQ in the base generation may differ considerably between populations because of their history. Conclusions Our results show that estimates of (co)variance components and derived genetic parameters were seriously biased (25% too high or too low) when assumptions on the relationship between DPQ in the statistical analysis did not agree with reality.

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Weaning results of beef Hungarian Fleckvieh calves 2. Genetic parameters, breeding values

Archives Animal Breeding ◽

10.5194/aab-53-26-2010 ◽

2010 ◽

Vol 53 (1) ◽

pp. 26-36 ◽

Cited By ~ 1

Author(s):

S. Bene ◽

I. Füller ◽

A. Fördős ◽

F. Szabó

Keyword(s):

Genetic Parameters ◽

Correlation Coefficients ◽

Breeding Value ◽

Phenotypic Variance ◽

Weaning Weight ◽

Breeding Values ◽

Estimated Breeding Values ◽

Genetic Value ◽

Maternal Heritability ◽

Daily Gain

Abstract. Weaning weight, preweaning daily gain and 205-day weight of Hungarian Fleckvieh calves (n=8 929, bulls =4 539, heifers =4 390) born from 232 sires between 1980 and 2003 were examined. Variance, covariance components and heritability values and correlation coefficients were estimated. The effect of the maternal permanent environment on genetic parameters and breeding values were examined. Two animal models were used for breeding value estimation. The direct heritability (hd2) of weaning weight, preweaning daily gain and 205-day weight was between 0.37 and 0.42. The maternal heritability (hm2) of these traits was 0.06 and 0.07. The direct-maternal correlations (rdm) were medium and negative −0.52 and −0.74. Contribution of the maternal heritability and maternal permanent environment to phenotype is smaller than that of direct heritabilities (hm2+c2< hd2). The ratio of the variance of maternal permanent environment in the phenotypic variance (c2) changed from 3 to 6 %. Estimated breeding values changed whether the permanent environmental effect of dam wasn’t taken into consideration but the rank of the animals was not modified. The genetic value for weaning results of Hungarian Fleckvieh population has increased since 1997.

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ESTİMATİON OF GENETİC AND ENVİRONMENTAL PARAMETERS AFFECTİNG PRODUCTİVİTY İN MORKARAMAN SHEEP AND ECONOMİC EVALUATİON OF PARAMETERS

Journal of Global Innovations in Agriculture Sciences ◽

10.22194/jgias/9.958 ◽

2021 ◽

pp. 155-161

Author(s):

Ufuk Karadavut ◽

Burhan Bahadır ◽

Volkan Karadavut ◽

Galip Şimşek ◽

Hakan İnci

Keyword(s):

Genetic Parameters ◽

Genetic Variance ◽

Additive Genetic Variance ◽

Environmental Parameters ◽

Error Variance ◽

Economic Importance ◽

Phenotypic Variance ◽

Economic Aspects ◽

Evaluation Of Parameters ◽

The Relationship

This study was carried out to protect the continuity of productivity in morkaraman sheep raised in Turkey and determine their economic importance. Morkaraman sheep are concentrated in the Eastern Regions of the country. The province of Bingöl, where the study was conducted, is located in this region and has an important morkaraman population. The study was carried out between 2008-2018. Sixty-eight morkaraman sheep were used during the study period out of 317 lambing lambs. In the study, the total number of lambs born per sheep (TNLBS), the number of weaned lambs (NWL), the weights of the lambs weaned per sheep (WLWS) and the total weight of the lambs weaned in the first period (TWLWFP) were determined. In addition, Additive genetic variance, Error variance, Phenotypic variance, Heritability and Ratio of error variation were determined for these variables. As a result, the correlation between the examined variables was significant and positive, except for the relationship between TNLBS and TWLWFP. The relationship between these two variables was significant but negative. Significant changes were also observed in terms of genetic parameters. It was concluded that the economic aspects of the examined variables should not be ignored in terms of sustainability. Keywords: Sheep, morkaraman, sustainability, genotypic and phenotypic variance.

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Estimation of genetic parameters and breeding values for litter size in the first three parity of landrace sows

Biotechnology in Animal Husbandry ◽

10.2298/bah1603261l ◽

2016 ◽

Vol 32 (3) ◽

pp. 261-269 ◽

Cited By ~ 1

Author(s):

Dragomir Lukac ◽

Vitomir Vidovic ◽

Teodora Vasiljevic ◽

Oliver Stankovic

Keyword(s):

Animal Model ◽

Genetic Parameters ◽

Multivariate Analyses ◽

Reproductive Traits ◽

Phenotypic Variance ◽

Breeding Values ◽

The Third ◽

Reproduction Traits ◽

Genetic And Phenotypic Correlations ◽

Estimated Breeding Values

The aim of this study was to estimate the genetic parameters and breeding values for reproduction traits of Landrace sows in the first three parities by Animal model. Records of 2238 first parity; 2125 second parity and 1872 third parity Landrace sows farrowing between 2007 and 2012 were included in the analysis. The traits included in the analyses were total pigs born (TB), number of pigs born alive (NBA), number of pigs weaned (NW) and litter weaning weight (LW) in the parities. The genetic parameters were estimated using a multivariate analyses Animal model using REML procedure. Estimates of heritability for TB were 0.03, 0.05 and 0.18, for NBA were 0.04, 0.02 and 0.17, for NW were 0.08, 0.08 and 0.01 and for LW were 0.09, 0.11 and 0.03 for parities 1 to 3. Genetic and phenotypic variance were increased from the first to the third parity. Between the majorities of studied reproductive traits were the recorded positive genetic and phenotypic correlations, except between LW and other analyzed properties where they recorded a high correlation negative in third parity. Means of estimated breeding values of reproductive traits from first parity to third parity was indecreased.

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Estimation of inbreeding effect on conception in Czech Holstein

Czech Journal of Animal Science ◽

10.17221/154/2018-cjas ◽

2019 ◽

Vol 64 (No. 7) ◽

pp. 309-316

Author(s):

Michala Hofmannová ◽

Josef Přibyl ◽

Emil Krupa ◽

Petr Pešek

Keyword(s):

Genetic Parameters ◽

Negative Impact ◽

Additive Genetic Variance ◽

Random Effect ◽

Inbreeding Coefficient ◽

Conception Rate ◽

Breeding Value ◽

Breeding Values ◽

Binary Model ◽

Animal Model Blup

The influence of calculated inbreeding coefficients on the conception of heifers and cows was analysed by a two-trait binary model for conceived/not conceived after each insemination on 677 234 Czech Holstein cows and heifers with 3 248 299 insemination records as the covariable in a statistical model. The data between 1996 and 2014 were analysed. Various effects and their statistical influence on traits were tested by a generalized linear model. Consequently, genetic parameters were estimated by the Gibbs sampling method and used in predicting breeding values using the best linear unbiased prediction by animal model (BLUP-AM). The mean for the conception rate of cows averaged over lactations was 33.7% and for heifers it reached 53.8%. Average inbreeding coefficient increased from 1% in 1996 to almost 5% by 2013 and was in the range of 0–45%. The rate of inbreeding per generation was 0.20%. Although the effect of inbreeding was statistically significant (P = 0.05) for both traits, the proportion of variability explained by the models was relatively low. Estimated genetic parameters were low for both traits. Coefficient of heritability was 2.00% and 1.30% for cows and heifers, respectively, whereas coefficients of repeatability reached 6.09% and 7.08% for cows and heifers, respectively. The random effect of the permanent environment (PE) reached higher values than the additive genetic variance (G) and explained 5.67% and 4.09% of variability for cows and heifers, respectively. A negative impact of inbreeding on heifer and cow conception was observed, whereby every 10% increase in inbreeding coefficient resulted in a conception decline by 2.23%. Calculated Spearman’s rank correlation coefficient between estimated breeding values considering and not considering the effect of inbreeding was close to one. Presented results indicate that inbreeding has a negligible influence on the breeding values of conception. The results also indicate that it is not necessary to include inbreeding coefficient in the routine breeding value evaluation of conception rate of heifers and cows. On the other hand, monitoring of inbreeding is necessary to avoid an increase of its rate.

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Selection on purebred and crossbred Performance for litter size in pigs*

Archives Animal Breeding ◽

10.5194/aab-43-249-2000 ◽

2000 ◽

Vol 43 (3) ◽

pp. 249-262 ◽

Cited By ~ 1

Author(s):

M. Bösch ◽

R. Röhe ◽

H. Looft ◽

E. Kalm

Keyword(s):

Genetic Correlation ◽

Litter Size ◽

Genetic Variance ◽

Additive Genetic Variance ◽

Genetic Parameter ◽

Selection Method ◽

Data Sets ◽

Phenotypic Variance ◽

Breeding Values ◽

Estimated Breeding Values

Abstract. The present study deals with estimation of genetic parameter for purebred and crossbred Performance of live born piglets, in order to choose the optimal selection method. Data sets of two pure breeds, line L03 and L04, with 5,422 sows, a two line crossbred, L303, with 3,553 sows and a three line crossbred, L350, with 3,609 sows of a North-German breeding Company were recorded. Estimated genetic correlation between purebred and crossbred Performance were rg = 0.59 and 0.40 for reciprocal crosses L03xL04 and L04xL03, respectively. Further investigations showed that the genetic correlation is influenced by genotype-environment interactions between a nucleus farm and a farm on production level. Full-sib effects showed a proportion of FS = 0.06 on the phenotypic variance of litter size. They were confounded with additive genetic variance and permanent environment variance, when full-sib effects were neglected. The percentage of equal selected purebred sires of line L03 were 80% when 30% of the sires selected on purebred or crossbred breeding values. Accuracy of estimated breeding values of purebred sires increased when crossbred Information were considered additionally from 0.32 to 0.38 for line L03 and 0.46 to 0.47 for line L04. Genetic correlation between purebred and crossbred Performance, the genetic connectedness between nucleus and production and the presence of genotype-environment interactions were analysed to have high influence on the value of additionally considered crossbred Performance.

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Variance components due to direct and maternal effects and estimation of breeding values for 12-week weight of Welsh Mountain lambs

Animal Science ◽

10.1017/s1357729800050918 ◽

1999 ◽

Vol 69 (2) ◽

pp. 345-352 ◽

Cited By ~ 13

Author(s):

M. Saatci ◽

I. Ap Dewi ◽

Z. Ulutas

Keyword(s):

Maternal Effects ◽

Variance Components ◽

Fixed Effects ◽

Additive Genetic Variance ◽

Selection Index ◽

Phenotypic Variance ◽

Common Environment ◽

Breeding Values ◽

Lamb Growth ◽

Selection Of

AbstractThe purpose of this study was to examine the importance of the genetic and maternal environmental factors influencing the 12-week weight (12WW) of Welsh Mountain lambs and to estimate genetic parameters for this trait. Records of 8880 Welsh Mountain lambs born between 1979 and 1995 were analysed. The records were from the nucleus flock of the CAMDA cooperative breeding group. In this flock selection of replacements had been based on a multi-trait index incorporating lamb growth and maternal ability as important objectives and 12WW as one of the selection criteria. Twelve models were examined, all including direct additive genetic variance and various combinations of genetic and environmental maternal effects. The most appropriate model was chosen based on log-likelihood ratio tests. It included appropriate fixed effects, and direct additive, maternal additive, maternal permanent environment and maternal common environment (litter) random effects that defined proportionally 0⋅21 (h2), 0⋅09 (m2), 0⋅06 (pe2) and 0⋅18 (ce2) of the phenotypic variance. Ignoring the additive maternal effect resulted in inflated estimates of direct heritability and ignoring the environmental effects associated with dam inflated the direct and maternal heritabilities. There was no correlation (P < 0⋅05) between the additive direct and additive maternal effects. Additive direct and maternal breeding values increased by 0⋅12 (s.e. 0⋅006) kg/year and 0Ό3 (s.e. 0⋅003) kg/year respectively. The results demonstrate the effective incorporation of selection index methodology in the context of a hill sheep flock and also the importance of several categories of maternal effects.

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Joint estimation of (co) variance components and breeding values for mean and dispersion of days from calving to first service in Holstein cow

Animal Production Science ◽

10.1071/an15643 ◽

2017 ◽

Vol 57 (4) ◽

pp. 760 ◽

Cited By ~ 1

Author(s):

Heydar Ghiasi ◽

Majbritt Felleki

Keyword(s):

Standard Deviation ◽

Genetic Correlation ◽

Additive Genetic Variance ◽

Joint Estimation ◽

Breeding Value ◽

Genetic Trend ◽

Breeding Values ◽

The Mean ◽

Estimated Breeding Values ◽

Genetic Standard Deviation

The present study explored the possibility of selection for uniformity of days from calving to first service (DFS) in dairy cattle. A double hierarchical generalised linear model with an iterative reweighted least-squares algorithm was used to estimate covariance components for the mean and dispersion of DFS. Data included the records of 27 113 Iranian Holstein cows (parity, 1–6) in 15 herds from 1981 to 2007. The estimated additive genetic variance for the mean and dispersion were 32.25 and 0.0139; both of these values had low standard errors. The genetic standard deviation for dispersion of DFS was 0.117, indicating that decreasing the estimated breeding value of dispersion by one genetic standard deviation can increase the uniformity by 12%. A strong positive genetic correlation (0.689) was obtained between the mean and dispersion of DFS. This genetic correlation is favourable since one of the aims of breeding is to simultaneously decrease the mean and increase the uniformity of DFS. The Spearman rank correlations between estimated breeding values in the mean and dispersion for sires with a different number of daughter observations were 0.907. In the studied population, the genetic trend in the mean of DFS was significant and favourable (–0.063 days/year), but the genetic trend in the dispersion of DFS was not significantly different from zero. The results obtained in the present study indicated that the mean and uniformity of DFS can simultaneously be improved in dairy cows.

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

Revista Brasileira de Zootecnia ◽

10.1590/s1516-35982010001000008 ◽

2010 ◽

Vol 39 (10) ◽

pp. 2155-2159 ◽

Cited By ~ 4

Author(s):

Leandro Barbosa ◽

Paulo Sávio Lopes ◽

Adair José Regazzi ◽

Robledo de Almeida Torres ◽

Mário Luiz Santana Júnior ◽

...

Keyword(s):

Litter Size ◽

Variance Components ◽

Genetic Parameters ◽

Random Effect ◽

Additive Model ◽

Fixed Effect ◽

Likelihood Method ◽

Phenotypic Variance ◽

Estimation Of Variance ◽

Genetic Trends

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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Evaluación fenotípica y genética para características de crecimiento en la raza criolla colombiana Costeño con Cuernos

Ciencia y Tecnología Agropecuaria ◽

10.21930/rcta.vol7_num2_art:65 ◽

2007 ◽

Vol 7 (2) ◽

pp. 12 ◽

Cited By ~ 3

Author(s):

Rodrigo Alfredo Martínez ◽

Juan Esteban Pérez ◽

Teófilo Herazo

Keyword(s):

Birth Weight ◽

Variance Components ◽

Fixed Effects ◽

Genetic Parameters ◽

Growth Traits ◽

Phenotypic Correlation ◽

Phenotypic Variance ◽

Direct Effects ◽

Weaning Weight ◽

Number Of Births

Se establecieron componentes de varianza, así como parámetros fenotípicos y genéticos, respecto de las variables ‘peso al nacimiento’, ‘peso al destete’ (ajustado a los 270 días) y ‘peso a los 480 días’ en un hato del ganado criollo colombiano Costeño con Cuernos. Se analizaron 2.281 registros de pesos al nacer, 1.722 de pesos al destete y 1.086 de pesos ajustados a los 480 días utilizando la metodología de máxima verosimilitud restringida (DFREML). También se ajustó un modelo animal que incluyó efectos genéticos directos, maternos y de ambiente permanente, asumiendo como efectos fijos el año de nacimiento, el sexo del ternero y el número de partos de la madre; finalmente, se estimaron los parámetros genéticos ‘heredabilidad’, ‘repetibilildad’ y se establecieron correlaciones genéticas y fenotípicas. Se reportan bajas estimaciones de heredabilidad de los efectos directos, que varían entre 0,17 ± 0,001 y 0,21 ± 0,074 para los pesos al nacer y al destete, respectivamente; así mismo, fue baja la heredabilidad de los efectos genéticos maternos con relación al peso al nacimiento, aunque estos estimados aumentaron respecto de los pesos al nacer y al destete. Las correlaciones entre efectos directos y maternos fueron negativas, pero el mayor valor se encontró para el peso al nacimiento (-0,89). La contribución del ambiente permanente como proporción de la varianza fenotípica total fue baja y disminuyó a medida que aumentó la edad del animal. Genetic and phenotypic evaluation to characterize growth traits of the native Colombian breed Costeño con CuernosFor a herd of native Colombian breed of cattle -Costeño con Cuernos (CCC)- estimates of variance components for phenotypic and genetic parameters were obtained for birth weight, weight at weaning (adjusted to 270 days) and weight at 480 days. Using the restricted maximum likelihood (REMI) methodology, 2281 birth weight records (PN), 1722 weaning weight records and 1086 weight records adjusted to 480 days were analyze by fitting a model which included direct and maternal genetics effects as well as permanent environmental effects, assuming that fixed effects were year of birth weight, calf gender and the mother number of births. The genetic parameters for heritability, repeatability, genetic and phenotypic correlation were estimated and genotypic and phenotypic correlation was established. Heritability estimates for direct effects are low and range from 0.17 ± 0.001 and 0.21 ± 0.074 for birth and weaning weight respectively; while estimates for maternal genetics effects were also low for PN, they were higher for weaning weight and weight at 480 days. There was a negative correlation between direct and maternal effects, and the higher value was for PN (-0.89). The contribution of the variable permanent environment measured as the contribution of the phenotypic variance was low and diminished as animal age increased.

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(Co)variance components and genetic parameters for growth rate and Kleiber ratio in fat-tailed Mehraban sheep

Archives Animal Breeding ◽

10.7482/0003-9438-56-055 ◽

2013 ◽

Vol 56 (1) ◽

pp. 564-572 ◽

Cited By ~ 1

Author(s):

F. Ghafouri-Kesbi

Keyword(s):

Growth Rate ◽

Variance Components ◽

Genetic Parameters ◽

Average Daily Gain ◽

Genetic Correlations ◽

Phenotypic Variance ◽

Genetic Progress ◽

Kleiber Ratio ◽

Derivative Free ◽

Maternal Heritability

Abstract. The aim of the present study was to estimate (co)variance components and genetic parameters for average daily gain from birth to weaning (ADGa), weaning to 6 months (ADGb), weaning to 9 months (ADGc), 6 months to 9 months (ADGd) and corresponding Kleiber ratios (KRa, KRb, KRc and KRd) in Mehraban sheep. A derivative-free algorithm combined with a series of six univariate linear animal models was used to estimate phenotypic variance and its direct, maternal and residual components. In addition, bivariate analyses were done to estimate (co)variance components between traits. Estimates of direct heritability (h2) were 0.10, 0.11, 0.16, 0.09, 0.13, 0.13, 0.15 and 0.08 for ADGa, ADGb, ADGc, ADGd, KRa, KRb, KRc and KRd, respectively and indicate that in Mehraban sheep genes contribute very little to the variance of the growth rate and Kleiber ratio. Estimates of maternal heritability (m2) were 0.10, 0.08 and 0.05 for ADGa, KRa and KRb, respectively. Direct additive genetic correlations ranged from −0.32 (KRa-KRd) to 0.99 (ADGb-KRb) and phenotypic correlations ranged from −0.53 (ADGa- ADGd) to 0.99 (ADGa-KRa). Estimates of direct heritability and genetic correlations show that genetic improvement in efficiency of feed utilization through selection programmes is possible, though it would generate a relatively slow genetic progress.

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