scholarly journals Estimation of additive and dominance variance for litter size components in rabbits

2014 ◽  
Vol 59 (No. 4) ◽  
pp. 182-189 ◽  
Author(s):  
I. Nagy ◽  
J. Farkas ◽  
I. Curik ◽  
G. Gorjanc ◽  
P. Gyovai ◽  
...  
Keyword(s):  
Environmental Effects ◽  
Variance Components ◽  
Correlation Coefficients ◽  
Data File ◽  
Breeding Value ◽  
Environmental Variance ◽  
Relative Significance ◽  
Breeding Values ◽  
Dead Animal ◽  
Additive Genetic Effects

Additive, dominance, and permanent environmental variance components were estimated for the number of kits born alive, number of kits born dead, and total number of kits born of a synthetic rabbit line (called Pannon Ka). The data file consisted of 11 582 kindling records of 2620 does collected between the years 1996–2013. The total number of animals in the pedigree files was 4012. The examined traits were evaluated using single-trait and two-trait (number of kits born alive-dead) animal models containing all or part of the following effects: additive genetic effects, permanent environmental effects, dominance effects. Heritability estimates calculated using the basic single-trait and two-trait models were 0.094 ± 0.018 and 0.090 ± 0.016 for number of kits born alive, 0.037 ± 0.010 and 0.041 ± 0.012 for number of kits born dead, and 0.117 ± 0.018 for total number of kits born, respectively. The relative significance of permanent environmental effects was 0.069 ± 0.014 and 0.069 ± 0.012 for number of kits born alive, 0.025 ± 0.011 and 0.023 ± 0.010 for number of kits born dead, and 0.060 ± 0.013 for total number of kits born, respectively. Using the extended single-trait and two-trait models, the ratios of the dominance components compared to the phenotypic variances were 0.048 ± 0.008 and 0.046 ± 0.007 for number of kits born alive, 0.068 ± 0.006 and 0.065 ± 0.006 for number of kits born dead, and 0.005 ± 0.0073 for total number of kits born, respectively. Genetic correlation coefficients between number of kits born alive and number of kits born dead were 0.401 ± 0.171 and 0.521 ± 0.182, respectively. Spearman’s rank correlations between the breeding values of the different single-trait models were close to unity in all traits (0.992–0.990). Much lower breeding value stability was found for two-trait models (0.384–0.898), especially for number of kits born dead. Results showed that the dominance components for number of kits born alive and number of kits born dead were not zero and affected the ranking of the animals (based on the breeding values).  

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

2019 ◽  
Vol 51 (1) ◽  
Author(s):  
Evert W. Brascamp ◽  
Piter Bijma
Keyword(s):  
Honey Bees ◽  
Variance Components ◽  
Genetic Parameters ◽  
Additive Genetic Variance ◽  
Breeding Value ◽  
Phenotypic Variance ◽  
Breeding Values ◽  
Estimated Breeding Values ◽  
Additive Genetic Relationship ◽  
The Relationship

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.

Selection of parents and estimation of genetic parameters using BLUP and molecular methods for lentil (Lens culinaris Medik.) breeding program in Argentina

2019 ◽  
Vol 56 (1) ◽  
pp. 12-25
Author(s):  
Carolina Bermejo ◽  
Federico Cazzola ◽  
Fernando Maglia ◽  
Enrique Cointry
Keyword(s):  
Quantitative Traits ◽  
Genetic Parameters ◽  
Selection Process ◽  
Recombinant Inbred Lines ◽  
Correlation Coefficients ◽  
Cost Effective ◽  
Molecular Data ◽  
Breeding Value ◽  
Breeding Values ◽  
High Yields

AbstractThe most important objective of lentil breeding programs is to develop new genotypes that are genetically more productive. Besides, it is necessary that the varieties obtained have short flowering cycles to allow the later sowing of summer crops. Selection is based through phenotypic means; however, we argue it should be based on genetic or breeding values because quantitative traits are often influenced by environments and genotype–environment interactions. The objectives of this study were to: (i) identify genotypes with the highest merit; (ii) estimate genetic parameters to know the genetic control of morphological traits in macrosperma and microsperma lentil types using best linear unbiased prediction (BLUP). Twenty-five recombinant inbred lines (RILs) from six F4 families selected on the basis of precocity and high yields were tested in four environments for important quantitative traits. The analysis of variance showed significant differences between genotypes, environments, and genotype–environment interactions for all the traits. Seven macrosperma- and two microsperma-type RILs were selected. Based on average ranking from breeding values and molecular data obtained with sequence-related amplified polymorphism (SRAP), the same genotypes were selected. Genotypic coefficients of variation, heritability across and by environment, and genetic correlation coefficients using BLUP were obtained. According to our results BLUP could replace molecular analysis methods because the selection process was simpler, more cost-effective, and more accurate. The breeding value of parents would give a better ranking of their genetic value than would their phenotypic value; therefore, the selection efficiency would be enhanced and the genetic gain would be more predictable. The selected genotypes could become potential commercial varieties or be used as parental lines in future hybridization programs.

Estimation of direct additive and maternal additive genetic effects for weaning weight in Mashona cattle of Zimbabwe using an individual animal model

1995 ◽  
Vol 60 (1) ◽  
pp. 41-48 ◽  
Author(s):  
C. T. Khombe ◽  
J. F. Hayes ◽  
R. I. Cue ◽  
K. M. Wade
Keyword(s):  
Animal Model ◽  
Variance Components ◽  
Mean Value ◽  
Individual Animal ◽  
Breeding Values ◽  
General Decline ◽  
Derivative Free ◽  
The Mean ◽  
Future Revision ◽  
Additive Genetic Effects

AbstractWeaning weights (or weight nearest to 205 days of age) from 8086 Mashona calves were collected from seven herds covering the period 1976 to 1988. Estimates of (co)variance components were obtained by restricted maximum likelihood using a derivative free algorithm and fitting an individual animal model. Estimates of direct additive heritability, maternal additive heritability, their correlation, total heritability and repeatability, obtained under two models were 0·243 and 0·281, 0·113 and 0·392, –0·282 and –0·269, 0·252 and 0·298, and 0·409 and 0·573, respectively. Trends within herd were estimated from the mean value of progeny born within a particular year. There were no significant trends in direct additive breeding values. A general decline in maternal breeding values was observed. Only one herd (herd 1) had a significant eroiyonmeYital freni (0·385 kg/year). It IMS emphftsilfiti that any future revision of the method used to improve the weaning weights of beef cattle should also improve their maternal breeding values.

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

2010 ◽  
Vol 53 (1) ◽  
pp. 26-36 ◽  
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.

565. A study of variation in twin cattle: III. Growth

1955 ◽  
Vol 22 (1) ◽  
pp. 1-9 ◽  
Author(s):  
J. W. B. King ◽  
H. P. Donald
Keyword(s):  
Environmental Effects ◽  
Live Weight ◽  
Genetic Effects ◽  
Point Of View ◽  
Environmental Variance ◽  
Simple Assumption ◽  
Polynomial Coefficients ◽  
Straight Line ◽  
Best Fitting ◽  
Additive Genetic Effects

1. Polynomial coefficients have been fitted to data on growth in live weight to 19 months and on height at withers to 27 months of age shown by one-egg (MZ) and two-egg (DZ) twins and pairs of half-sisters (HZ). The coefficients obtained (a0, a2 and a3) have been subjected to analysis of variance.2. For growth in live weight, the ratio of intrapair variances for MZ, DZ and HZ pairs was 1:6·8:10 for a1, which gives the straight line best fitting the observed curve. Unrelated pairs, it is calculated, would have had an intrapair variance 20·9 times as great as MZ pairs. From the point of view of minimizing the intrapair variance, the advantage of the MZ pairs was usually a little less for a0, and considerably less for a2 and a3.3. For height at withers, the results were similar to those for weight.4. The contribution of environmental variance to total intrapair variance increased from a0 to a3, while that due to additive genetic effects diminished. Owing to the wide fiducial limits applicable, the results can be accommodated assuming only additive genetic effects in addition to environmental effects as estimated from one-egg twins. The extent to which HZ pairs exceeded the variance expected, however, suggests that this simple assumption may prove inadequate.

scholarly journals Phenotypic plasticity for life-history traits in Drosophila melanogaster. III. Effect of the environment on genetic parameters

1992 ◽  
Vol 60 (2) ◽  
pp. 87-101 ◽  
Author(s):  
M. D. Gebhardt ◽  
S. C. Stearns
Keyword(s):  
Drosophila Melanogaster ◽  
Variance Components ◽  
Life History Traits ◽  
Additive Genetic Variance ◽  
Dry Weight ◽  
Developmental Time ◽  
Environmental Variance ◽  
Directional Dominance ◽  
Yeast Concentration ◽  
Additive Genetic Effects

SummaryWe estimated genetic and environmental variance components for developmental time and dry weight at eclosion in Drosophila melanogaster raised in ten different environments (all combinations of 22, 25 and 28°C and 0·5, 1 and 4% yeast concentration, and 0·25% yeast at 25°C). We used six homozygous lines derived from a natural population for complete diallel crosses in each environment. Additive genetic variances were consistently low for both traits (h2 around 10%). The additive genetic variance of developmental time was larger at lower yeast concentrations, but the heritability did not increase because other components were also larger. The additive genetic effects of the six parental lines changed ranks across environments, suggesting a mechanism for the maintenance of genetic variation in heterogenous environments.The variance due to non-directional dominance was small in most environments. However, there was directional dominance in the form of inbreeding depression for both traits. It was pronounced at high yeast levels and temperatures but disappeared when yeast or temperature were decreased. This meant that the heterozygous flies were more sensitive to environmental differences than homozygous flies. Because dominance effects are not heritable, this suggests that the evolution of plasticity can be constrained when dominance effects are important as a mechanism for plasticity.

scholarly journals Zusammenhang zwischen Parametern des Glukosetoleranztestes bei Jungbullen und deren Nachkommenzuchtwert

2000 ◽  
Vol 43 (3) ◽  
pp. 231-240 ◽  
Author(s):  
L. Panicke ◽  
R. Staufenbiel ◽  
O. Burkert ◽  
E. Fischer ◽  
F. Reinhardt
Keyword(s):  
Glucose Tolerance ◽  
Glucose Tolerance Test ◽  
Correlation Coefficients ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Breeding Value ◽  
Central Position ◽  
Intravenous Glucose ◽  
Genetic Determination ◽  
Breeding Values

Abstract. Title of the paper: Relationships between parameters of the glucose tolerance test by young sires and estimated their breeding values A high milk Performance connected to a sound health regarding metabolism and a sufficient fertility in dairy cows depends on a well balanced distribution of energy in body. The terms "type of tumover" and "type of deposition" embody two extremes of food energy preferably for milk production or for body composition. Insulin plays an outstanding role based on its central position in energetic metabolism. The function of insulin may be recorded by means of the intravenous glucose tolerance test (GTT). The reaction of insulin and glucose was investigated after infusion of 1 g Glucose/kg075 because of the probable genetic determination of the reactive ability. The coefficients of heritability range from h2 = 0.16 + 0.10 to h2 = 0.28 ± 0.16. Investigating 28 sires the correlation coefficients amount to r = 0.5 for parameters of gluccose tolerance test and estimated breeding values which is closer than those between pedigree breeding value and glucose tolerance test.This is expecting additional Information for young sires before the insert of the test.

scholarly journals Stability of estimated breeding values for average daily gain in Pannon White rabbits

2011 ◽  
Vol 56 (No. 8) ◽  
pp. 365-369 ◽  
Author(s):  
I. Nagy ◽  
J. Farkas ◽  
P. Gyovai ◽  
I. Radnai ◽  
Z. Szendrő
Keyword(s):  
Average Daily Gain ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
The Other ◽  
Breeding Value ◽  
Breeding Values ◽  
Spearman’S Rank Correlation ◽  
The Common ◽  
Estimated Breeding Values ◽  
Daily Gain

Stability of estimated breeding values for average daily gain (ADG) between 5 and 10 weeks of age was analysed for 47 242 Pannon White rabbits, reared in 7470 litters and born between 2000 and 2008. The dataset was divided into 5 successive 5-year periods: (1) 2000&ndash;2004, (2) 2001&ndash;2005, (3) 2002&ndash;2006, (4) 2003&ndash;2007, and (5) 2004&ndash;2008. Then, after selecting the appropriate part of the pedigree for these sub-datasets, genetic parameters and breeding values were estimated for ADG using REML and BLUP methods. In the applied models sex, year-month, animal and random litter effects were considered. Estimated heritabilities for all 5 periods from 1 to 5 were moderate and stable (0.28 &plusmn; 0.01, 0.28 &plusmn; 0.02, 0.29 &plusmn; 0.02, 0.27 &plusmn; 0.02, and 0.28 &plusmn; 0.02). Magnitudes of random litter effects were low and stable (0.14 &plusmn; 0.01, 0.15 &plusmn; 0.01, 0.15 &plusmn; 0.01, 0.16 &plusmn; 0.01, and 0.16 &plusmn; 0.01). After breeding value estimation the dataset of period 5 was merged pair-wise with the other periods 4, 3, 2 and 1 using an inner join. Thus only the common records of the datasets representing the periods 5-4, 5-3, 5-2, and 5-1 were included in the merged datasets. In these merged datasets each rabbit had two breeding values for ADG based on two different periods. Spearman's rank correlation coefficients were calculated between the breeding values based on the dataset of period 5 and the other periods. With the successive years the rank correlation coefficients decreased (0.989, 0.979, 0.965 and 0.924). The correlation coefficients between ranks remained moderately high, even when the proportion of the common rabbits in the merged datasets was low. However, a reasonable re-ranking occurred among the top animals. Rank correlations for the top 100 and 1000 animals varied from 0.41 to 0.55 and from 0.37 to 0.54, respectively, which could influence selection efficiency if the rolling base were used for genetic evaluation.

scholarly journals 17 Investigating pig survival in different productive stages using genomic models

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 14-15
Author(s):  
Natalia Leite ◽  
Daniela Lourenco ◽  
Egbert Knol ◽  
Marcos Lopes ◽  
Fabyano Silva
Keyword(s):  
Maternal Effects ◽  
Variance Components ◽  
Single Step ◽  
Breeding Value ◽  
Genomic Information ◽  
Gene Effects ◽  
Breeding Values ◽  
Variance Components Estimation ◽  
Individual Survival ◽  
The Individual

Abstract Pig survival is an economically important trait with animal welfare implications. Although survival is highly affected by the environment, previous studies reported genetic variability of this trait, indicating the opportunity for improvement through selection. Genomic information is currently included in the major commercial pig breeding programs, which can be incorporated by single-step genomic BLUP (ssGBLUP). The objectives of this study were to: 1) estimate (co)variance components for farrowing, lactation, nursery, and finishing survival; and 2) compare the individual breeding value accuracies obtained using traditional pedigree-based BLUP (BLUP) and ssGBLUP methods. Individual survival records were collected for a crossbred pig population, and two-trait threshold models, which included maternal effects, were used for (co)variance components estimation. Direct and maternal breeding values were estimated using BLUP and ssGBLUP methods, and individual accuracies were obtained based on posterior standard deviation. Heritabilities for the four survival phases were low, ranging from 0.04 to 0.12. Pre-weaning survival was controlled by dam and piglet additive gene effects. The additive direct and maternal components were equally important at farrowing, whereas the piglet’s own genetic merit was the most expressive during lactation. Common environment estimates were higher than maternal genetic effects, indicating early life experiences related to the sow, but independent of the maternal genetic component. Nursery and finishing survival showed the same or higher heritabilities compared to pre-weaning stages. The genetic correlation between the pre-weaning phases was high (0.68), whereas the correlation between the post-weaning measurements was moderate (0.42). The incorporation of genomic information through ssGBLUP increased the individual accuracy, on average, from 0.36 to 0.41 for direct and from 0.29 to 0.37 for maternal effects compared to BLUP. Although the heritabilities for survival in different productive stages are low, genetic gains can be obtained, given that breeding values benefit from the inclusion of genomic information.

scholarly journals Evaluation of Hungarian Sporthorse mare performance tests

2010 ◽  
pp. 83-87
Author(s):  
János Posta ◽  
István Komlósi ◽  
Sándor Mihók
Keyword(s):  
Variance Components ◽  
Fixed Effects ◽  
Movement Analysis ◽  
Breeding Value ◽  
Performance Tests ◽  
Breeding Values ◽  
Movement Index ◽  
Value Estimation ◽  
The Mean ◽  
Trait Group

Results of the Hungarian Sporthorse mare performance tests were evaluated. Data from the period of 1993-2009 were used, coveringscores of 618 3-year-old and 310 4-year-old mares, 109 of them were tested at both ages. Seventeen traits were scored on the tests, whichcovered ten conformational, three free jumping performance and four movement analyses traits, respectively. Breeding value estimation wasbased on BLUP animal model. Test year, age and owner were included in the model as fixed effects. Variance components were estimatedwith VCE-6 software package. Heritabilities ranged from 0.32 (frame) to 0.50 (saddle region) for conformation traits, from 0.39 (jumpingstyle) to 0.49 (jumping ability and jumping skill) for free jumping traits and from 0.20 (walk) to 0.48 (canter) for movement analysis traits.Breeding value indexes were constructed for each trait group. Conformation index was computed based on the weighted scores of thebreeding values of conformational traits. The conformational score scales were used as weightings. Free jumping and movement indexescontain the proper breeding values with equal weights. A total index was also constructed using conformation index, two times the freejumping index and two times the movement index. Each breeding values and breeding value indexes were presented with the mean 100 andstandard deviation of 20 for the easier understanding.

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