scholarly journals Animal Model Versus Polynomial Legendre Test-Day In Dairy Cattle

2020 ◽  
Vol 23 (1) ◽  
pp. 5-12
Author(s):  
Mircea Cătălin Rotar ◽  
Horia Grosu ◽  
Mihail Alexandru Gras ◽  
Rodica Ştefania Pelmuş ◽  
Cristina Lazăr ◽  
...  
Keyword(s):  
Animal Model ◽  
Dairy Cattle ◽  
Fixed Effects ◽  
Rank Correlation ◽  
Pedigree Information ◽  
Lactation Period ◽  
Data Set ◽  
Breeding Values ◽  
Normal Limits ◽  
Model Versus

AbstractThe aim of the study was to compare the classical animal model (based on total milk for 305 days) with the Test-Day model (using monthly records of milk yield from Official Records of Performances). The data set derived from a total 175 animals (cows with records, parents of these animals and the descendants) from two Romanian breeds (Romanian Black Spotted and Montbeliarde), the phenotypic and the pedigree information arisen from National Research Development Institute for Animal Biology and Nutrition (IBNA-Balotesti). The selection criteria to be included in the analysis for each cow was to have at least 3 test-days and the days in milk between 200 and 330 for the Test-Day model and the total amount of the 305- day lactation yield for classical Animal Model respectively. Both models use B.L.U.P methodology and for that reason all the estimates were adjusted for fixed effects and all the breeding values and the solution for fixed effects were estimated simultaneous. For the animal model the fixed effects used was the breed and the year of performing and for the Test-Day model was an extra one, the test day effect. The correlation calculated between test days was very high (over 90%) for consecutive tests, and was getting lower when the days between tests was higher (under 40%). Also, in terms of heritability the values were in normal limits throughout lactation, except at the beginning and end of lactation period where these values were a little bit higher. The comparison of the ranking of breeding values with Spearman rank correlation shows that in 80% of the cases the ranking was similar for both models. As the ranking correlations shows, it is certain that the two models are very similar when they are used for genetic evaluation. But, in conclusion, we can say that for a better lactation curve estimation it is recommending to use test-day model for dairy cattle.

scholarly journals Estimation of genetic parameters for melanoma in the Old Kladruber horse

2012 ◽  
Vol 57 (No. 2) ◽  
pp. 75-82 ◽  
Author(s):  
L. Vostrý ◽  
B. Hofmanová ◽  
H. Vostrá Vydrová ◽  
J. Přibyl ◽  
I. Majzlík
Keyword(s):  
Animal Model ◽  
Genetic Variation ◽  
Correlation Coefficient ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Rank Correlation ◽  
Genetic Effect ◽  
Pedigree Information ◽  
Direct Genetic Effect ◽  
Estimation Of Genetic Parameters

The aim of this study was to assess the prevalence of melanoma to investigate a possible genetic variation of this trait in the Old Kladruber horse. A total of 564 grey varieties of the Old Kladruber horse, 238 males and 326 females, with five generations of ancestors (n = 1245 animals) were analysed. Melanoma status was recorded for different stages. Three different analyses were conducted: a linear animal model (LM) with melanoma classified into five categories, threshold animal model (TM) with melanoma classified into five categories and threshold animal model (TMb) with melanoma classified into two categories (0 = absence, 1 = presence). All models included the fixed effects of year of evaluation, age, line, sex, greying level, random direct genetic effect, and the effect of animal’s permanent environment. Heritability for melanoma occurrence was estimated for LM – 0.09, for TM – 0.27, and for TMb – 0.11. The coefficient of repeatability was estimated for LM – 0.77, for TM – 0.90, and for TMb – 0.99. The values of the Pearson’s correlation coefficient and Spearmen’s rank correlation coefficient among breeding values estimated by LM, TM, and TMb models were from 0.82 to 0.88 and from 0.83 to 0.90, respectively, for data with pedigree information and from 0.77 to 0.84 and 0.77 to 0.88, respectively, for a subset of animals with measurements. Results suggest that additive genetic variation of melanoma occurrence in the Old Kladruber horse seems large enough to be exploited in a specific breeding programme.  

Autoregressive repeatability model for genetic evaluation of longitudinal reproductive traits in dairy cattle

2020 ◽  
Vol 87 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Hugo T. Silva ◽  
Paulo S. Lopes ◽  
Claudio N. Costa ◽  
Fabyano F. Silva ◽  
Delvan A. Silva ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Environmental Effects ◽  
Rank Correlation ◽  
Reproductive Traits ◽  
Genetic Evaluation ◽  
Information Criteria ◽  
Ar Model ◽  
Genetic Progress ◽  
Data Set ◽  
Genetic Evaluations

AbstractWe investigated the efficiency of the autoregressive repeatability model (AR) for genetic evaluation of longitudinal reproductive traits in Portuguese Holstein cattle and compared the results with those from the conventional repeatability model (REP). The data set comprised records taken during the first four calving orders, corresponding to a total of 416, 766, 872 and 766 thousand records for interval between calving to first service, days open, calving interval and daughter pregnancy rate, respectively. Both models included fixed (month and age classes associated to each calving order) and random (herd-year-season, animal and permanent environmental) effects. For AR model, a first-order autoregressive (co)variance structure was fitted for the herd-year-season and permanent environmental effects. The AR outperformed the REP model, with lower Akaike Information Criteria, lower Mean Square Error and Akaike Weights close to unity. Rank correlations between estimated breeding values (EBV) with AR and REP models ranged from 0.95 to 0.97 for all studied reproductive traits, when the total bulls were considered. When considering only the top-100 selected bulls, the rank correlation ranged from 0.72 to 0.88. These results indicate that the re-ranking observed at the top level will provide more opportunities for selecting the best bulls. The EBV reliabilities provided by AR model was larger for all traits, but the magnitudes of the annual genetic progress were similar between two models. Overall, the proposed AR model was suitable for genetic evaluations of longitudinal reproductive traits in dairy cattle, outperforming the REP model.

Linear and threshold model genetic parameters for disease, fertility and milk production in dairy cattle

2000 ◽  
Vol 71 (3) ◽  
pp. 411-419 ◽  
Author(s):  
H. N. Kadarmideen ◽  
R. Thompson ◽  
G. Simm
Keyword(s):  
Dairy Cattle ◽  
Milk Production ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Threshold Model ◽  
Production Traits ◽  
Milk Production Traits ◽  
Model Framework ◽  
Data Set ◽  
Fertility Traits

AbstractThis study provides estimates of genetic parameters for various diseases, fertility and 305-day milk production traits in dairy cattle using data from a UK national milk recording scheme. The data set consisted of 63891 multiple lactation records on diseases (mastitis, lameness, milk fever, ketosis and tetany), fertility traits (calving interval, conception to first service, number of services for a conception, and number of days to first service), dystocia and 305-day milk, fat and protein yield. All traits were analysed by multi-trait repeatability linear animal models (LM). Binary diseases and fertility traits were further analysed by threshold sire models (TM). Both LM and TM analyses were based on the generalized linear mixed model framework. The LM included herd-year-season of calving (HYS), age at calving and parity as fixed effects and genetic, permanent environmental and residual effects as random. The TM analyses included the same effects as for LM, but HYS effects were treated as random to avoid convergence problems when HYS sub-classes had 0 or 100% incidence. Because HYS effects were treated as random, herd effects were fitted as fixed effects to account for effect of herds in the data. The LM estimates of heritability ranged from 0•389 to 0•399 for 305-day milk production traits, 0•010 to 0•029 for fertility traits and 0•004 to 0•038 for diseases. The LM estimates of repeatability ranged from 0•556 to 0•586 for 305-day milk production traits, 0•029 to 0•086 for fertility traits and 0•004 to 0•100 for diseases. The TM estimates of heritabilities and repeatabilities were greater than LM estimates for binary traits and were in the range 0•012 to 0•126 and 0•013 to 0•168, respectively. Genetic correlations between milk production traits and fertility and diseases were all unfavorable: they ranged from 0•07 to 0•37 for milk production and diseases, 0•31 to 0•54 for milk production and poor fertility and 0•06 to 0•41 for diseases and poor fertility. These results show that future selection programmes should include disease and fertility for genetic improvement of health and reproduction and for sustained economic growth in the dairy cattle industry.

Repeatability and bias of estimated breeding values for dairy bulls and bull dams calculated from animal model evaluations

1993 ◽  
Vol 57 (2) ◽  
pp. 175-182 ◽  
Author(s):  
P. Uimari ◽  
E. A. Mäntysaari
Keyword(s):  
Animal Model ◽  
Dairy Cow ◽  
Relative Weight ◽  
Breeding Value ◽  
Potential Bias ◽  
Data Set ◽  
Breeding Values ◽  
Dairy Bulls ◽  
Estimated Breeding Values ◽  
Genetic Standard Deviation

AbstractAn animal model and an approximative method for calculating repeatabilities of estimated breeding values are used in Finnish dairy cow evaluation. Changes in estimated breeding values over time as daughters accumulate were studied. Special emphasis was given to the accuracy and potential bias in the pedigree indices of young sires. The data set used was the same as in the national evaluation and the traits investigated were protein yield and somatic cell count. The average repeatability in evaluation of bulls without daughters was 0·37. The empirical repeatability defined as a squared correlation between the pedigree index and the final sire proof was only 0·15. The reduction in the repeatability was attributed to the selection on pedigree index. The upward bias observed in pedigree indices was 5 kg (approx. 0·3 of genetic standard deviation). The bias was caused by the overestimation of bull dams' breeding value. Also the proofs of bull sires increased after the second crop of daughters. The correlation between the evaluations of the same sire calculated from two separate equal size daughter groups was 0·91 when the bull had 10 to 50 daughters and 0·87 with over 100 daughters. This illustrates how the relative weight of the pedigree decreases while more progeny information is accumulated in the evaluation.

scholarly journals Short communication: Estimation of genetic trends for body weight traits in Markhoz goat at different ages

2019 ◽  
Vol 17 (1) ◽  
pp. e04SC01 ◽  
Author(s):  
Meysam Latifi ◽  
Mohammad Razmkabir
Keyword(s):  
Body Weight ◽  
Fixed Effects ◽  
Growth Traits ◽  
Genetic Selection ◽  
Information Criteria ◽  
Pedigree Information ◽  
Genetic Trend ◽  
Breeding Values ◽  
Different Ages ◽  
Genetic Trends

The objective of the present study was to estimate genetic trends for body weight at different ages in Markhoz goat, including birth weight (BW, n = 4758), weaning weight (WW, n= 3685), 6-month weight (6MW, n = 3420), 9-month weight (9MW, n = 3032) and 12-month weight (12MW, n = 2697). Data and pedigree information were collected from 1992 until 2014 at the Breeding Center of Markhoz goat, Sanandaj, Iran. The GLM procedure of SAS was used for selecting the variables and identifying significant fixed effects in the equation of model. Various animal models were applied for genetic analysis and the best model was determined based on Akaike information criteria (AIC). Breeding values of animals were predicted using Wombat program. Genetic trends were obtained by regressing the average predicted breeding values on birth year for each trait. Based on the best model, direct estimated genetic trends were positive and significance for WW, 6MW, 9MW and 12 MW were 15.51, 26.28, 58.36 and 76.70 g/year, respectively (p<0.001). Maternal genetic trend for BW and WW were 0.61 and 5.47 g/year, respectively (p<0.01). The low and moderate generic trends obtained in the present study, indicated the possibility of growth traits improvements through genetic selection at all ages in Markhoz goat.

EVALUATION OF DAIRY CATTLE FOR FINAL CLASS USING ANIMAL MODELS

1988 ◽  
Vol 68 (3) ◽  
pp. 639-645 ◽  
Author(s):  
J. JAMROZIK ◽  
L. R. SCHAEFFER
Keyword(s):  
Animal Models ◽  
Dairy Cattle ◽  
Fixed Effects ◽  
Genetic Relationships ◽  
Residual Effects ◽  
Breeding Values ◽  
Stage Of Lactation ◽  
Key Words Animal ◽  
Estimated Breeding Values ◽  
Genetic Evaluations

Estimated breeding values for final class of 364 868 Canadian Holstein Friesian cows and 10 186 bulls from three different animal models were compared. FIRST lactation, first classifications were described by a model with fixed effects of herd-round-classifier, linear and quadratic effects of age at calving and stage of lactation at classification, and random effects of additive genetic effects of cows, and residual effects. All additive genetic relationships among animals were included. A second model used the LATEST classification on each cow rather than the first and these observations were pre-adjusted for age and stage. The third model used ALL classifications on each cow, and these were also pre-adjusted for age and stage effects. Correlations among estimated breeding values between methods ranged from 0.92 to 0.95. Estimated breeding values from LATEST were most highly correlated to sire proofs from the currently official sire model which also used the latest classification of each cow. Correlations of estimated breeding values between sires and their sons showed that results from LATEST were more accurate than results from the other two models. A model similar to that for LATEST is proposed for official genetic evaluations for conformation in the Canadian Holstein population. Key words: Animal model, conformation, dairy cattle

scholarly journals Direct and Competition Additive Effects in Tree Breeding: Bayesian Estimation From an Individual Tree Mixed Model

2008 ◽  
Vol 57 (1-6) ◽  
pp. 45-56 ◽  
Author(s):  
E. P. Cappa ◽  
R. J. C. Cantet
Keyword(s):  
Environmental Effects ◽  
Fixed Effects ◽  
Mixed Model ◽  
Phenotypic Variance ◽  
Tree Model ◽  
Data Set ◽  
Additive Variance ◽  
Individual Tree ◽  
Breeding Values ◽  
Competition Effects

Abstract An individual tree model with additive direct and competition effects is introduced to account for competitive effects in forest genetics evaluation. The mixed linear model includes fixed effects as well as direct and competition breeding values plus permanent environmental effects. Competition effects, either additive or environmental, are identified in the phenotype of a competitor tree by means of ‘intensity of competition’ elements (IC), which are non-zero elements of the incidence matrix of the additive competition effects. The ICs are inverse function of the distance and the number of competing individuals, either row-column wise or diagonally. The ICs allow standardization of the variance of competition effects in the phenotypic variance of any individual tree, so that the model accounts for unequal number of neighbors. Expressions are obtained for the bias in estimating additive variance using the covariance between half-sibs, when ignoring competition effects for row-plot designs and for single-tree plot designs. A data set of loblolly pines on growth at breast height is used to estimate the additive variances of direct and competition effects, the covariance between both effects, and the variance of permanent environmental effects using a Bayesian method via Gibbs sampling and Restricted Maximum Likelihood procedures (REML) via the Expectation- Maximization (EM) algorithm. No problem of convergence was detected with the model and ICs used when compared to what has been reported in the animal breeding literature for such models. Posterior means (standard error) of the estimated parameters were σ̂2Ad = 12.553 (1.447), σ̂2Ac = 1.259 (0.259), σ̂AdAc = -3.126 (0.492), σ̂2 p = 1.186 (0.289), and σ̂2e = 5.819 (1.07). Leaving permanent environmental competition effects out of the model may bias the predictions of direct breeding values. Results suggest that selection for increasing direct growth while keeping a low level of competition is feasible.

scholarly journals Genetic parameter of birth and weaning weights for Friesian calves by using an animal model

2005 ◽  
Vol 48 (3) ◽  
pp. 261-269 ◽  
Author(s):  
H. Atil ◽  
A. S. Khattab ◽  
L. Badawy
Keyword(s):  
Animal Model ◽  
Birth Weight ◽  
Fixed Effects ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Likelihood Method ◽  
Multiple Trait ◽  
Breeding Values ◽  
Heritability Estimates ◽  
Maternal Heritability

Abstract. Birth and weaning weights of 556 Friesian calves by 41 sires out of 318 different dams over a 11 years period were obtained from a herd of Friesian in Sakha Experimental Farm, Ministry of Agriculture, Egypt were used. The records were analyzed by Multiple Trait Likelihood Method (MTDFREML) by using a repeatability animal model (BOLDMAN et al., 1995). Convergence was attained after 699 iterations. The fixed effects included in the model were season and year of calving, parity and sex and the random effects were direct and maternal genetic, permanent maternal environmental and error. Direct heritability estimates for birth weight (BW) and weaning weight (WW) are 0.28 and 0.13, respectively, while, maternal heritability estimates for the same traits are 0.14 and 0.06, respectively. Repeatability estimates are 0.75 and 0.15 for BW and WW, respectively. Phenotypic and genetic correlations are 0.89 and 0.80, respectively. Estimates of calve breeding values ranged from −3.12 to 4.11 kg for BW and ranged from −4.10 to 5.11 kg for WW. Sire breeding values ranged from −3.40 to 2.99 kg for BW and ranged from −2.50 to 4.47 kg for WW. Dam breeding values ranged from −6.80 to 5.54 kg for BW and ranged from -6.10 to 6.39 kg for WW.

scholarly journals Genetische Analyse von Klauenmaßen aus der Eigenleistungsprüfung von Jungbullen

2003 ◽  
Vol 46 (2) ◽  
pp. 155-165
Author(s):  
D. Hinrichs ◽  
T. O. Kuhlmann ◽  
E. Stamer ◽  
E. Kalm
Keyword(s):  
Fixed Effects ◽  
Performance Test ◽  
Rank Correlation ◽  
Breeding Value ◽  
Dorsal Wall ◽  
Breeding Values ◽  
Black And White ◽  
Genetische Analyse ◽  
Value Estimation ◽  
Holstein Bulls

Abstract. Title of the paper: Genetic analysis of claw measurements from the performance test of young bulls The present study deals with the analysis of the claw measurements length of dorsal wall, length of heel, high of heel, diagonal, angle of dorsal wall and hardness of claw horn from the performance test of young bulls. Data collection take place at one fore leg and one hind leg from 798 young German Holstein bulls (black and white, red and white) and 89 young Angler bulls. The analysis of the systematic fixed effects was followed by the estimation of genetic parameters. A breeding value estimation was done with some of the claw traits and rank correlation for the breeding values of the claw traits and some official exterieur breeding values and the length of productive life were calculated. Heritabilities ranked from 0.00 (hardness of claw horn, upper point of measurement of hind leg) to 0.45 (diagonal of the foreleg). Genetic correlation between fore leg and hind leg vary between 0.14 and 0.99. Rank correlation of the claw trait breeding values ranked from –0.65 to 0.64. Rank correlation between official breeding values and claw trait breeding values vary from –0.27 to 0.37.

scholarly journals Parameters of glucose tolerance test traits in dairy cattle

2006 ◽  
Vol 49 (2) ◽  
pp. 120-132
Author(s):  
G. Freyer ◽  
R. Staufenbiel ◽  
E. Fischer ◽  
L. Panicke
Keyword(s):  
Glucose Tolerance ◽  
Dairy Cattle ◽  
Fixed Effects ◽  
Glucose Tolerance Test ◽  
Original Data ◽  
Tolerance Test ◽  
Logarithmic Transformation ◽  
Breeding Values ◽  
Glucose Challenge ◽  
Dairy Bulls

Abstract. Numerous studies in dairy cattle focused on measuring the content of hormones, metabolites and enzyme activities in blood. Response on glucose challenge in 620 dairy bulls within a defined period of 340 … 450 days of age is targeted on within this paper. The time response course after glucose challenge was the basis for selecting corresponding response traits. Deviation from normal distribution was taken into account by means of comparing parameters of original data, after logarithmic transformation and breeding values obtained from both. The residual plots did not confirm the necessity of logarithmic transformation. After evaluating fixed effects trait-specifically, individual breeding values for glucose tolerance test traits were estimated. Heritability coefficients were promising for using these traits in cattle breeding. Trait specific heritability coefficients for G0 was 0.22 and 0.26, for Ga 0.23 and 0.18, for GHL 0.31 and 0.39 from logarithmic and original trait observations, respectively.

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