scholarly journals Evaluation of Breeding Value Based on Scores Achieved in the Polish Championships for Young Horses

2015 ◽  
Vol 15 (4) ◽  
pp. 879-887
Author(s):  
Tomasz Próchniak ◽  
Iwona Rozempolska-Rucińska ◽  
Grzegorz Zięba ◽  
Marek Łukaszewicz
Keyword(s):  
Genetic Improvement ◽  
Genetic Parameters ◽  
Performance Test ◽  
Breeding Value ◽  
Genetic Trend ◽  
Breeding Values ◽  
Physical Traits ◽  
Young Horses ◽  
Show Jumping ◽  
Detailed Picture

Abstract Genetic improvement of show jumping horses is problematic, given the multitude of physical traits that determine sport usability and the specific mental predispositions required during training and competitions. The Polish Championships for Young Horses (PCYH) provide an opportunity to evaluate usability traits in Polish horses, which, however, is not a basis for evaluation of the breeding value. The aim of the study was to propose a model for evaluation of the breeding value of horses taking part in the Championships. In total, 1232 starts of 894 4-, 5-, 6-, and 7-year-old horses were analysed. Indices of BLUP breeding values were calculated based on 7 traits with known genetic parameters (ranking in the championship, style rating on days 1, 2, and 3, and penalty points on days 1, 2, and 3). A low and irregular genetic trend, significant only in the case of penalties scored on days 1 and 2 of the championships, was shown. Compatibility of the evaluation of the breeding value estimated on the basis of scores achieved in the Polish Championships for Young Horses with the scores of the performance test carried out in Training Centres was shown. It was also demonstrated that the “sum penalty” and “sum style” measured during the three days of the Championships is sufficient for evaluation of the BLUP breeding value. It was suggested that the evaluation combined with the results achieved at the PCYH (in four age categories) would provide a more detailed picture of the genetic predispositions of jumping horses.

scholarly journals Genetic parameters and principal components analysis of breeding value for birth and weaning weight in Egyptian buffalo

2021 ◽  
Vol 34 (1) ◽  
pp. 12-19
Author(s):  
Mohamed Mahmoud Ibrahim Salem ◽  
Amin Mohamed Said Amin ◽  
Ayman Fouad Ashour ◽  
Mohamed Mohamed El-said Ibrahim ◽  
Mohammed Kotb Abo-Ismail
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Breeding Value ◽  
Genetic Trend ◽  
Weaning Weight ◽  
Breeding Values ◽  
Factors Affecting ◽  
Components Analysis

Objective: The objectives of the current study were to study the main environmental factors affecting birth weight (BW) and weaning weight (WW), estimate variance components, genetic parameters and genetic trend and to evaluate the variability and relationships among breeding value of BW and WW using principal components analysis (PCA).Methods: A total of 16,370 records were collected from 8,271 buffalo calves. Genetic parameters and breeding values were estimated using a bivariate animal model which includes direct, maternal and permanent maternal effects. These estimates were standardized and used in PCA.Results: The direct heritability estimates were 0.06 and 0.41 for BW and WW, respectively whereas direct maternal heritability values were 0.03 and 0.14, respectively. Proportions of variance due to permanent environmental effects of dam were 0.455 and 0.280 for BW and WW respectively. The genetic correlation between BW and WWs was weak approaching zero, but the maternal correlation was 0.26. The first two principal components (PC1 and PC2) were estimated utilizing the standardized breeding values according to Kaiser method. The total variance explained by the first two PCs was 71.17% in which 45.91% and 25.25% were explained by PC1 and PC2, respectively. The direct breeding values of BW were related to PC2 but those of WW and maternal breeding values of BW and WWs were associated with PC1.Conclusion: The results of genetic parameters and PCA indicate that BW and WWs were not genetically correlated and improving growth traits of Egyptian buffaloes could be achieved using WW without any adverse effect by BW.

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.

scholarly journals Genomic Correlations Between the Gaits of Young Horses Measured by Accelerometry and Functional Longevity in Jumping Competition

2021 ◽  
Vol 12 ◽  
Author(s):  
Manon Dugué ◽  
Bernard Dumont Saint Priest ◽  
Harmony Crichan ◽  
Sophie Danvy ◽  
Anne Ricard
Keyword(s):  
Principal Components ◽  
Genomic Data ◽  
Principal Component ◽  
Well Being ◽  
Relationship Matrix ◽  
Significant Qtls ◽  
Breeding Values ◽  
A Genome ◽  
Young Horses ◽  
Show Jumping

Functional longevity is essential for the well-being of horses and the satisfaction of riders. Conventional selection using longevity breeding values calculated from competition results is not efficient because it takes too long to obtain reliable information. Therefore, the objective was to identify early criteria for selection. We assessed two types of early criteria: gait traits of young horses and QTLs. Thus, our aim was to estimate the genetic correlation between gait traits and longevity and to perform a genome-wide association study (GWAS) for longevity. Measurements of gaits by accelerometry were recorded on 1,477 show jumping horses that were 4 to 5 years old. Gait analysis provided 9 principal components describing trot, canter, and walk. Longevity estimated breeding values (EBVs) for stallions were calculated using a survival analysis of more than 900,000 years of performances by 179,448 show jumping horses born from 1981 onwards. Longevity was measured as the number of years spent in competition. Model included region and month of birth, age at first competition, year, and performance level. Longevity EBVs were deregressed to obtain weighted pseudo-performances for 1,968 stallions. Genomic data were available for 3,658 jumping horses. Seventy-eight percent of the horses measured for gaits and twenty-five percent of those measured for longevity were genotyped. A GWAS of longevity revealed no significant QTLs. Genetic parameters between each of the 9 principal components of the gait variables and longevity were evaluated with a bi-trait animal linear mixed model using single-step GBLUP analysis with the relationship matrix constructed from genomic data and genealogy (24,448 ancestors over four generations). The heritability of the gait traits varied from 0.11 to 0.44. The third principal component for trot (high lateral activity) and the first principal component for canter (high dorsoventral activity and low stride frequency) were moderately genetically correlated with higher longevity: rg = 0.38 (0.15) and 0.28 (0.13), respectively. Our study revealed that functional longevity is a polygenic trait with no major genes. We found new correlations between longevity and gait traits. Before using gait characteristics in a selection plan, these correlations need to be understood better at the biomechanical level.

scholarly journals Genomic selection for white spot syndrome virus resistance in whiteleg shrimp boosts survival under an experimental challenge test

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marie Lillehammer ◽  
Rama Bangera ◽  
Marcela Salazar ◽  
Sergio Vela ◽  
Edna C. Erazo ◽  
...  
Keyword(s):  
Genomic Selection ◽  
Genetic Improvement ◽  
White Spot Syndrome Virus ◽  
Random Mating ◽  
Challenge Test ◽  
White Spot ◽  
Breeding Value ◽  
Genomic Breeding ◽  
Breeding Values ◽  
White Spot Syndrome

AbstractWhite spot syndrome virus (WSSV) causes major worldwide losses in shrimp aquaculture. The development of resistant shrimp populations is an attractive option for management of the disease. However, heritability for WSSV resistance is generally low and genetic improvement by conventional selection has been slow. This study was designed to determine the power and accuracy of genomic selection to improve WSSV resistance in Litopenaeus vannamei. Shrimp were experimentally challenged with WSSV and resistance was evaluated as dead or alive (DOA) 23 days after infestation. All shrimp in the challenge test were genotyped for 18,643 single nucleotide polymorphisms. Breeding candidates (G0) were ranked on genomic breeding values for WSSV resistance. Two G1 populations were produced, one from G0 breeders with high and the other with low estimated breeding values. A third population was produced from “random” mating of parent stock. The average survival was 25% in the low, 38% in the random and 51% in the high-genomic breeding value groups. Genomic heritability for DOA (0.41 in G1) was high for this type of trait. The realised genetic gain and high heritability clearly demonstrates large potential for further genetic improvement of WSSV resistance in the evaluated L. vannamei population using genomic selection.

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.

scholarly journals Analysis of non-genetic and genetic influences underlying the growth of Kajli lambs

2020 ◽  
Vol 50 (4) ◽  
pp. 613-625
Author(s):  
A. Ali ◽  
K. Javed ◽  
I. Zahoor ◽  
K.M. Anjum
Keyword(s):  
Birth Weight ◽  
Genetic Correlation ◽  
Fixed Effects ◽  
Genetic Correlations ◽  
Breeding Value ◽  
Season Of Birth ◽  
Genetic Trend ◽  
Breeding Values ◽  
Heritability Estimates ◽  
Birth Type

Data on 2931 Kajli lambs, born from 2007 to 2018, were used to quantify environmental and genetic effects on growth performance of Kajli sheep. Traits considered for evaluation were birth weight (BWT), 120-day adjusted weight (120DWT), 180-day adjusted weight (180DWT), 270-day adjusted weight (270DWT), and 365-day adjusted weight (365DWT). Fixed effects of year of birth, season of birth, sex, birth type, and dam age on these traits were evaluated using linear procedures of SAS, 9.1. Similarly, BWT, 120DWT, 180DWT, and 270DWT were used as fixed effects mixed model analyses. Variance components, heritability and breeding values were estimated by restricted maximum likelihood. The genetic trend for each trait was obtained by regression of the estimated breeding values (EBV) on year of birth. Analyses revealed substantial influence of birth year on all traits. Sex and birth type were the significant sources of variation for BWT and 120DWT. Season of birth did not influence birth weight meaningfully, but had a significant role in the expression of 120DWT, 180DWT, and 270DWT. Heritability estimates were generally low (0.003 ± 0.018 to 0.099 ± 0.067) for all traits. With the exception of the genetic correlation of 180DWT and 365DWT, the genetic correlations between trait were strong and positive. Only 365DWT had a positive genetic trend. Although the heritability estimates for almost all weight traits were low, high and positive genetic correlations between BWT and other weight traits suggest that selection based on BWT would result in the improvement of other weight traits as a correlated response.Keywords: bodyweight, breeding value, genetic correlation, sheep

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.

scholarly journals Estimation of inbreeding effect on conception in Czech Holstein

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.

scholarly journals Application of genomic selection in agriculture

2018 ◽  
Vol 33 (4) ◽  
Author(s):  
Neeraj Budhlakoti ◽  
D. C. Mishra ◽  
Devendra Arora ◽  
Rajeev Ranjan Kumar
Keyword(s):  
Genomic Selection ◽  
Marker Assisted Selection ◽  
Genetic Improvement ◽  
Breeding Value ◽  
Slow Time ◽  
Phenotypic Data ◽  
Breeding Values ◽  
Sequencing Technologies ◽  
Breeding Technique ◽  
Density Marker

Traditional breeding technique for genetic improvement of crops are based on, information on phenotypes and pedigrees to predict breeding values, has been found very successful. But, genetic gain through this technique is found to be very slow, time consuming. However, Due to availability of latest DNA sequencing technologies, now it is possible to estimate breeding values more accurately by using information on variation in DNA sequence. Lots of research has been done in direction of marker assisted selection, still it has some limitation on its implementation. Genomic selection (GS) is proposed to overcome such limitation. GS is a form of marker-assisted selection in which genetic markers covering the whole genome are used. GS predicts breeding value using information available on phenotype and high density marker. Several techniques has been developed for selection and prediction of genotype, these techniques are based on analysis of genotypic and phenotypic data.

scholarly journals Genetic trend for jumping performance in Czech warm-blooded horses

2004 ◽  
Vol 52 (1) ◽  
pp. 97-102
Author(s):  
Iva Jiskrová
Keyword(s):  
Animal Model ◽  
Regression Analysis ◽  
Regression Coefficient ◽  
Breeding Value ◽  
Positive Trend ◽  
Genetic Trend ◽  
Breeding Values ◽  
Jumping Performance ◽  
The Mean ◽  
Estimated Breeding Value

Data on the jumping performance of horses in the period of 1991 - 2002 were analysed. The data included 252781 starts of 10671 horses in 10911 jumping competitions. The performance was characterised on the basis of the obtained bad points (penalties) of the competing horses. The BLUP Animal model was used to estimate the breeding value of the sport horses; the genetic trend in the jumping performance of the Czech warm-blooded horse was assessed on the basis of these results. Regression analysis and calculations of the mean breeding values based on the year of birth were used to determine the dependence of the estimated breeding value on the year of birth. The jumping performance of the population of the Czech warm-blooded horse shows a positive trend. The regression coefficient of –0.1337 shows the genetic trend in the population, which means an increasing jumping performance of the horses expressed in reduced earnings of bad points by 0.1337 in dependence on the year of birth.

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