scholarly journals Genetic parameters for clinical mastitis in Czech Holstein cattle

2020 ◽  
Vol 65 (No. 12) ◽  
pp. 463-472
Author(s):  
Ludmila Zavadilová ◽  
Eva Kašná ◽  
Zuzana Krupová ◽  
Michaela Brzáková
Keyword(s):  
Genetic Parameters ◽  
Genetic Correlations ◽  
Clinical Mastitis ◽  
Breeding Value ◽  
Holstein Cattle ◽  
Environmental Variance ◽  
Breeding Values ◽  
Lower Accuracy ◽  
Variance Ratios ◽  
Type Traits

Genetic parameters were estimated for clinical mastitis in Czech Holstein cattle. The datasets included 14 329 cows with 28 626 lactations. Clinical mastitis was defined as 0/1 occurrence per lactation. Single- or multi-trait repeatability linear animal models were employed for estimation of (co)variances and prediction of conventional or genomic breeding values. The inclusion of the random herd-year-month effect in the model was analysed. The estimated heritability for clinical mastitis ranged from 2.10% to 2.72%, while permanent environmental variance ratios or random herd-year-month effect ratios were twice higher than heritability. In the multi-trait models, udder type traits, such as fore udder attachment, rear udder attachment, rear udder width, front teat placement and udder depth, were employed. The highest genetic correlations of clinical mastitis occurred with rear udder width (0.41) and the lowest with front teat placement (–0.10). Both the multi-trait model and the genomic model provided breeding value estimates with higher reliability. In contrast, the model with random herd-year-season effects provided breeding values with lower accuracy.

scholarly journals Breeding value for type traits in beef cattle in theCzech Republic

2011 ◽  
Vol 50 (No. 9) ◽  
pp. 385-393 ◽  
Author(s):  
Z. Veselá ◽  
J. Přibyl ◽  
P. Šafus ◽  
L. Vostrý ◽  
K. Šeba ◽  
...  
Keyword(s):  
Fixed Effects ◽  
Genetic Correlations ◽  
Live Weight ◽  
Breeding Value ◽  
Body Measurements ◽  
Breeding Values ◽  
Production Type ◽  
Type Traits ◽  
Method Of Evaluation ◽  
Range Of Values

The type was evaluated in 5 424 young animals of twelve beef breeds. Ten type traits were evaluated: height at sacrum (HS), body length (BL), live weight (LW), front chest width (CW), chest depth (CD), pelvis (P), shoulder muscling (SM), back muscling (BM), rump muscling (RM) and production type (PT). The traits represent two groups: (1) traits scoring body measurements and body capacity (HS, BL, LW, CW, CD, P) and (2) traits scoring muscling (SM, BM, RM, PT). These fixed effects were included in the model: breed, sex, HYS, mother&rsquo;s age, linear regression on age at evaluation and average gain from birth to evaluation. Fixed effects in the model explained 40% to 60% of variability. The highest values of heritability coefficient were estimated for HS (h<sup>2</sup> = 0.51) and LW (h<sup>2</sup> = 0.50). BL had the lowest values of heritability coefficient (h<sup>2</sup> = 0.25). The values h<sup>2</sup> = 0.25&ndash;0.32 were calculated for the traits scoring body capacity (CW, CD, P). The range of values for muscling traits was h<sup>2</sup>&nbsp;= 0.26&ndash;0.35. The coefficient of heritability for PT was h<sup>2</sup> = 0.34. All traits scoring muscling and PT showed high genetic correlations (r<sub>g</sub> &gt; 0.95). The traits scoring body capacity (P, CW, CD) were highly genetically correlated with muscling r<sub>g</sub> &gt; 0.83. Breeding values were determined by a multi-trait animal model. Standard deviations of breeding values were higher in HS (s<sub>BV</sub> = 0.71) and LW (s<sub>BV</sub> = 0.84), which was connected with a different method of evaluation of these traits. They were in the range of 0.19 (BL) to 0.30 (RM) in the other traits. &nbsp;

scholarly journals Estimation of Genetic Parameters of Type Traits in First Parity Cows of the Autochthonous Cika Cattle in Slovenia

2021 ◽  
Vol 12 ◽  
Author(s):  
Mojca Simčič ◽  
Barbara Luštrek ◽  
Miran Štepec ◽  
Betka Logar ◽  
Klemen Potočnik
Keyword(s):  
Fixed Effects ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Genetic Effect ◽  
Breeding Value ◽  
Additive Genetic Effect ◽  
Body Frame ◽  
Herd Effect ◽  
Long Time ◽  
Type Traits

The aim of this study was to estimate genetic parameters of 26 individual and four composite type traits in first parity Cika cows. An analysis of variance was performed with the generalized linear model procedure of the SAS/STAT statistical package, where the fixed effects of year of recording, cow’s age at recording and days after calving as a linear regression were included in the model. The variance components for the direct additive genetic effect and the herd effect in all type traits were estimated using the REML method in the VCE-6 software package. The estimated heritabilities ranged from 0.42 to 0.67 for the measured body frame traits, from 0.36 to 0.80 for the scored autochthonous traits, from 0.11 to 0.61 for the scored body frame traits, and from 0.20 to 0.47 for the scored udder traits. The estimated heritabilities for the composite traits called “autochthonous characteristics”, “muscularity”, “body frame” and “udder” were 0.55, 0.19, 0.19, and 0.26, respectively. The estimated genetic correlations among the measured body frame traits were positive and high, while the majority of them among the scored body frame traits were low to moderate. The estimated proportions of variance explained by the herd effect for the composite traits “autochthonous characteristics,” “muscularity,” “body frame” and “udder” were 0.09, 0.28, 0.14, and 0.10, respectively. The estimated heritabilities for the type traits of first parity Cika cows were similar to those reported for other breeds where breeding values have been routinely predicted for a long time. All estimated genetic parameters are already used for breeding value prediction in the Cika cattle population.

scholarly journals Analysis of Czech cold-blooded horses: genetic parameters, breeding value and the influence of inbreeding depression on linear description of conformation and type characters

2011 ◽  
Vol 56 (No. 5) ◽  
pp. 217-230 ◽  
Author(s):  
L. Vostrý ◽  
Z. Čapková ◽  
J. Přibyl ◽  
K. Mach
Keyword(s):  
Czech Republic ◽  
Inbreeding Depression ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Breeding Value ◽  
Residual Variance ◽  
Linear Type ◽  
The Czech Republic ◽  
Breeding Values

Genetic parameters, breeding values and inbreeding depression for 22 linear type description of conformation and type characters and 4 body measurements were evaluated in a group of 1744 horses of three original cold-blooded breeds in the Czech Republic in a long period of 18 years (1990&ndash;2007). Based on the values of Akaike's information criterion, residual variance and heritability coefficient, a model with fixed effects (sex, year of description, breed, and classifier) and with a random effect (animal) was selected. Heritability coefficients for the particular traits were in the range of 0.11 to 0.55 and genetic correlations ranged from &ndash;0.63 to 0.97. Inbreeding depression, expressed as coefficients of regression on one percent of inbreeding, was in the range of &ndash;0.0992 to 0.0242 points for the particular traits. The inclusion of inbreeding depression in the model resulted in a moderate change in h<sup>2</sup> in one-third of the traits. In two-thirds of traits, the value of r<sub>G</sub> increased or decreased by 0.01. Standard deviations of the breeding values for linear type description of conformation and type characters were in the range of 0.30 to 0.72 and 0.62 to 6.18 for body measurement traits. Among breeding values estimated by a model without inbreeding depression and a model with inbreeding depression, Spearman's rank correlation coefficient values for the particular traits were 0.916&ndash;0.999 (sample of all horses), 0.710&ndash;0.992 (10% of the best horses) and 0.827&ndash;0.998 (10% of the worst horses). If the average value of the inbreeding coefficient is low (0.03), then it is not necessary to include the influence of inbreeding depression in the model for the genetic evaluation of individuals of original cold-blooded horses kept in the Czech Republic.

scholarly journals New Test Day Model for the Genetic Evaluation of mastitis in dairy cattle

2008 ◽  
pp. 1-6
Author(s):  
E. Negussie ◽  
K. Vuori ◽  
I. Strandén ◽  
E. A. Mäntysaari
Keyword(s):  
Genetic Parameters ◽  
Genetic Correlations ◽  
Predictive Ability ◽  
High Standard ◽  
Clinical Mastitis ◽  
Genetic Evaluation ◽  
Random Regression ◽  
Breeding Values ◽  
Random Regression Model ◽  
Future Evaluation

In this study, genetic parameters of test-day (TD) somatic cell score (SCS) and lactation average (LA)clinical mastitis (CM) were estimated using a random regression model (RRM) that combine two differentdata models. A multitrait RRM (mt-RRM) was then developed for the genetic evaluation of mastitis.Estimates of breeding values (EBVs) from the mt-RRM were compared to corresponding multitrait LAmodel (biv-LAM) and univariate LA models (univ-LAM). A total of 147500 and about 5.6 million recordsfrom 27500 and 1.4 million Finnish Ayrshire cows were used for estimation of genetic parameters andprediction of breeding values, respectively. Heritabilities of CM1 and CM2 traits: (CM1, -7 to 30 andCM2, 31 to 300 DIM) were 0.026 and 0.016, respectively, while for TD SCS they ranged from 0.06 to0.11. During first lactation, the genetic correlations between TD SCS and CM1 and between TD SCS andCM2 varied from 0.40 to 0.77 and from 0.34 to 0.71, respectively. In genetic evaluation of mastitis, modelcomparisons have showed that mt-RRM has high model predictive ability and high standard deviation ofbreeding values. Moreover, it has added advantages of making efficient use of available TD SCSinformation and offers proofs for bulls and cows. Therefore, mt-RRM can be used as best practical modelin the future evaluation of animals for mastitis resistance.

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.

Genetic analysis of docility score of Australian Angus and Limousin cattle

2018 ◽  
Vol 58 (2) ◽  
pp. 213 ◽  
Author(s):  
S. F. Walkom ◽  
M. G. Jeyaruban ◽  
B. Tier ◽  
D. J. Johnston
Keyword(s):  
Adverse Effect ◽  
Animal Model ◽  
Genetic Analysis ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Costs ◽  
Breeding Value ◽  
Maternal Behaviour ◽  
Production Traits ◽  
Subjective Score

The temperament of cattle is believed to affect the profitability of the herd through impacting production costs, meat quality, reproduction, maternal behaviour and the welfare of the animals and their handlers. As part of the national beef cattle genetic evaluation in Australia by BREEDPLAN, 50 935 Angus and 50 930 Limousin calves were scored by seedstock producers for temperament using docility score. Docility score is a subjective score of the animal’s response to being restrained and isolated within a crush, at weaning, and is scored on a scale from 1 to 5 with 1 representing the quiet and 5 the extremely nervous or anxious calves. Genetic parameters for docility score were estimated using a threshold animal model with four thresholds (five categories) from a Bayesian analysis carried out using Gibbs sampling in THRGIBBS1F90 with post-Gibbs analysis in POSTGIBBSF90. The heritability of docility score on the observed scale was 0.21 and 0.39 in Angus and Limousin, respectively. Since the release of the docility breeding value to the Australian Limousin population there has been a favourable trend within the national herd towards more docile cattle. Weak but favourable genetic correlations between docility score and the production traits indicates that docility score is largely independent of these traits and that selection to improve temperament can occur without having an adverse effect on growth, fat, muscle and reproduction.

scholarly journals Estimation of genetic parameters and comparison of random regression animal and sire models of production traits in the first three lactations of Iranian Holsteins

2014 ◽  
Vol 30 (2) ◽  
pp. 261-279 ◽  
Author(s):  
A. Mohammadi ◽  
S. Alijani
Keyword(s):  
Milk Fat ◽  
Genetic Parameters ◽  
Additive Genetic Variance ◽  
Genetic Correlations ◽  
Random Regression ◽  
Lactation Period ◽  
Production Traits ◽  
Environmental Variance ◽  
In The Beginning ◽  
Residual Variances

This study was conducted to compare of random regression (RR) animal and sire models for estimation of the genetic parameters for production traits of Iranian Holstein dairy cows. For this purpose, the test day records were used belonged to first three lactations of cows and for, milk, fat and protein yields traits where, collected from 2003 to 2010, by the national breeding center of Iran. The genetic parameters were estimated using restricted maximum likelihood algorithm. To compare the model, different criterion -2logL value, AIC, BIC and RV were used for considered traits. Residual variances were considered homogeneous over the lactation period. Obtained results showed that additive genetic variance was highest in the beginning and end lactation and permanent environmental variance was highest in beginning of lactation than other lactation period. Heritabilities estimate for milk, fat and protein yields by RR animal and sire models were found to be lowest during early lactation (0.05, 0.04 and 0.07; 0.05, 0.19 and 0.13; 0.14, 0.19 and 0.15, for milk, fat and protein yields and in first, second and third lactation respectively). However, estimated heritabilities during lactation did not vary among different order Legendre polynomials, and also between RR animal and sire models. The variation in genetic correlations estimate in the RR animal and sire models was larger in the first lactation than in the second and third lactations. Thus, based on the results obtained, it can be inferred that the RR animal model is better for modeling yield traits in Iranian Holsteins.

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 Genetic parameters for test day milk yield of first lactation Holstein cows estimated by random regression using Legendre polynomials

2008 ◽  
Vol 37 (4) ◽  
pp. 602-608 ◽  
Author(s):  
Claudio Napolis Costa ◽  
Claudio Manoel Rodrigues de Melo ◽  
Irineu Umberto Packer ◽  
Ary Ferreira de Freitas ◽  
Nilson Milagres Teixeira ◽  
...  
Keyword(s):  
Variance Components ◽  
Legendre Polynomials ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Random Regression ◽  
Holstein Cows ◽  
Residual Variance ◽  
Environmental Variance ◽  
Environmental Correlations ◽  
Lp Estimates

Data comprising 263,390 test-day (TD) records of 32,448 first parity cows calving in 467 herds between 1991 and 2001 from the Brazilian Holstein Association were used to estimate genetic and permanent environmental variance components in a random regression animal model using Legendre polynomials (LP) of order three to five by REML. Residual variance was assumed to be constant in all or in some classes of lactation periods for each LP. Estimates of genetic and permanent environmental variances did not show any trend due to the increase in the LP order. Residual variance decreased as the order of LP increased when it was assumed constant, and it was highest at the beginning of lactation and relatively constant in mid lactation when assumed to vary between classes. The range for the estimates of heritability (0.27 - 0.42) was similar for all models and was higher in mid lactation. There were only slight differences between the models in both genetic and permanent environmental correlations. Genetic correlations decreased for near unity between adjacent days to values as low as 0.24 between early and late lactation. A five parameter LP to model both genetic and permanent environmental effects and assuming a homogeneous residual variance would be a parsimonious option to fit TD yields of Holstein cows in Brazil.

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

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