scholarly journals Estimates of genetic parameters of trotting performance traits for repeated annual records

1997 ◽  
Vol 6 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Jukka Pösö ◽  
Matti Ojala
Keyword(s):  
Animal Model ◽  
Maximum Likelihood ◽  
Variance Components ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Improve Accuracy ◽  
Performance Traits ◽  
Genetic And Phenotypic Correlations ◽  
Genetic Evaluations ◽  
Very High

The heritability and repeatability of trotting performance traits and genetic and phenotypic correlations among these traits were estimated from repeated annual records of 6934 Finnhorse and 5298 Standardbred trotters. The number of observations in the two breeds was 19 550 and 14 184, respectively. (Co)variance components were obtained with animal model and restricted maximum likelihood (REML) method. The heritability estimates were highest for time traits (0.29 to 0.35) and lowest for number of starts (0.08 to 0.10) in the two breeds. The repeatability estimates were high for time traits but only moderate for other trotting performance traits, suggesting that repeated records improve accuracy in genetic evaluations. The genetic correlations among the performance traits, especially between time and money traits, were very high and favourable considering the breeding goals. The phenotypic associations were distinctly weaker than the genetic ones.

scholarly journals Use of individual race results in the estimation of genetic parameters of trotting performance for Finnhorse and Standardbred trotters

1999 ◽  
Vol 8 (4-5) ◽  
pp. 353-363 ◽  
Author(s):  
T. THUNEBERG-SELONEN ◽  
J. PÖSÖ ◽  
E. MÄNTYSAARI
Keyword(s):  
Animal Model ◽  
Maximum Likelihood ◽  
Variance Components ◽  
Fixed Effects ◽  
Environmental Effect ◽  
Genetic Parameters ◽  
Genetic Effect ◽  
Additive Genetic Effect ◽  
Performance Traits ◽  
Estimation Of Genetic Parameters

The heritability and repeatability for trotting performance traits were estimated from individual race results. Data comprised of records from 1991 to 1995 for 4808 Finnhorses and from 1993 to 1995 for 5869 Standardbred trotters. The statistical model included the additive genetic effect of an animal and two permanent environmental effects, and the fixed effects of sex, age, starting method*starting lane combination, driver and race. The first permanent environmental effect described repeatability over a horse’s career while the second one characterized repeatability within a racing year. Variance components for three trotting performance traits were estimated by the animal model and the method of restricted maximum likelihood (REML). Heritability and repeatability estimates were moderately high for time at finish (h 2 =0.23–0.28 and r=0.50–0.57), moderate for ranking within a race (h 2 =0.12 and r=0.25) and low for earnings (h 2 =0.05–0.09 and r=0.15–0.18). Time at finish seemed to be the most usable measure of trotting performance because of its wide information substance. However, time at finish does not take into account records of disqualified horses or of those which did not finish, but use of earnings, either from individual race results or preferably from annual records, is one possible way to consider records of such horses.;

scholarly journals Genetic parameters of production and reproduetive traits in on a farm tested Danish Large White and Landrace swine in Greece

2000 ◽  
Vol 43 (3) ◽  
pp. 287-298
Author(s):  
J. Bizelis ◽  
A. Kominakis ◽  
E. Rogdakis ◽  
F. Georgadopoulou
Keyword(s):  
Maximum Likelihood ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Traits ◽  
Likelihood Methods ◽  
Large White ◽  
Reproduction Traits ◽  
Maximum Likelihood Methods ◽  
Genetic And Phenotypic Correlations

Abstract. Production and reproduetive traits in Danish Landrace (LD) and Large White (LW) swine were analysed by restricted maximum likelihood methods to obtain heritabilities as well as genetic and phenotypic correlations. Production traits were: age, backfat thickness (BT), muscle depth (MD) and the ratio BT/MD, adjusted to Standard bodyweight of 85 kg. Reproduction traits were: number of pigs born (NB) and number of pigs weaned (NW) per sow and parity. Heritabilities for age, BT, MD and BT/MD were 0.60, 0.44, 0.51 and 0.42 for LD and 0.36, 0.44, 0.37 and 0.45 for LW, respectively. Genetic correlations between age and BT were −0.22 in LD and – 0.44 in LW. The genetic correlation between age and MD was close to zero in both breeds. Genetic correlation between BT and MD were −0.36 and −0.25 in LD and LW, respectively. Heritabilities for NB were 0.25 in LD and 0.13 in LW while heritabilities for NW were close to zero in both breeds. Genetic correlation between NB and NW was 0.46 and 0.70 in LD and LW, respectively.

Genetic parameter estimations and genomic insights for teat and udder structure in young and mature Canadian Angus cows

2021 ◽  
Author(s):  
K Devani ◽  
J J Crowley ◽  
G Plastow ◽  
K Orsel ◽  
T S Valente
Keyword(s):  
Animal Model ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Age Groups ◽  
Morbidity And Mortality ◽  
Parameter Estimations ◽  
Angus Cattle ◽  
Genetic Evaluations

Abstract Poor teat and udder structure, frequently associated with older cows, impact cow production and health, as well as calf morbidity and mortality. However, producer culling, for reasons including age, production, feed availability, and beef markets, creates a bias in teat and udder scores assessed and submitted to the Canadian Angus Association for genetic evaluations towards improved mammary structure. In addition, due to the infancy of the reporting program, repeated scores are rare. Prior to adoption of genetic evaluations for teat and udder scores in Canadian Angus cattle, it is imperative to verify that teat and udder scores from young cows are the same trait as teat and udder scores estimated on mature cows. Genetic parameters for teat and udder scores from all cows (n=4,192), and then from young cows (parity 1 and 2) and from mature cows (parity ≥ 4) were estimated using a single trait animal model. Genetic correlations for the traits between the two cow age groups were estimated using a two-trait animal model. Estimates of heritability (PSD) were 0.32 (0.07) and 0.45 (0.07) for young teat and udder score, and 0.27 (0.07) and 0.31 (0.07) for mature teat and udder score, respectively. Genetic correlation (PSD) between the young and mature traits was 0.87 (0.13) for teat score and 0.40 (0.17) for udder score. GWAS were used to further explore the genetic and biological commonalities and differences between the two groups. Although there were no genes in common for the two udder scores, 12 genes overlapped for teat score in the two cow age groups. Interestingly, there were also 23 genes in common between teat and udder scores in mature cows. Based on these findings, it is recommended that producers collect teat and udder score on their cow herd annually.

scholarly journals EFFECT OF FIXED FACTORS AND ESTIMATION OF GENETIC PARAMETERS OF GROWTH TRAITS FOR MOUNTAIN KIDS

2019 ◽  
Vol 50 (6) ◽  
Author(s):  
Hermiz & Baper
Keyword(s):  
Variance Components ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Maximum Likelihood Method ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Likelihood Method ◽  
Phenotypic Correlations ◽  
Body Weights ◽  
Genetic And Phenotypic Correlations

Body weights at birth (469), weaning (394) and at six month of age (358) for kids utilized in this study were raised at private project in Duhok governorate, Iraq during two kidding season (2016-2017) and (2017-2018). GLM within SAS programme was used to analyze the data which include the fixed effects (age of doe, year and season of kidding, sex of kid and type of birth, regression on doe weight at kidding, and the regression of later weights of kids on earlier weights) influencing the studied traits. Restricted Maximum Likelihood Method was used to estimate repeatability, heritability, genetic and phenotypic correlations after adjusting the records for fixed effects. Variance components of random effects were tested for positive definite. Overall mean of weights at birth (BWT), weaning (WWT) and 6 month of age (WT6M) were 2.92, 15.32 and 24.45 kg, respectively. Differences among groups of age of doe in all studied traits were not significant, while year of kidding and sex of kid affect all traits significantly (p<0.01). Season of kidding affect BWT and WWT significantly (P<0.01). Single born kids were heavier (P<0.01) than twins in BWT only. Regression of BWT on doe weight at kidding (0.033 kg/kg) was significant (P<0.01), while the regressions of WWT and WT6M were not significant. The regression coefficients of WWT on BWT (1.906 kg/kg) and of WT6M on WWT (0.835 kg/kg) were highly significant (P<0.01). Repeatability estimates for BWT, WWT and WT6M were 0.47, 0.45 and 0.35, respectively; on the same order the estimates of heritability were 0.41, 0.61 and 0.79. Genetic correlations between BWT with each of WWT (0.45) and WT6M (0.55), and between WWT and WT6M (0.68) were highly significant. All phenotypic correlations between each pair of body weights were higher than genetic correlations and ranged between 0.48 and 0.73.

scholarly journals Estimation of Genetic and Phenotypic Parameters for Udder Morphology Traits in Different Dairy Sheep Genotypes

2017 ◽  
Vol 65 (1) ◽  
pp. 105-110
Author(s):  
Pavol Makovický ◽  
Milan Margetín ◽  
Peter Makovický
Keyword(s):  
Animal Model ◽  
Maximum Likelihood ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Restricted Maximum Likelihood ◽  
Primary Data ◽  
Dairy Sheep ◽  
Multiple Trait

Knowledge of genetic parameters is the basis of sound livestock improvement programmes. Genetic parameters have been estimated for linear udder traits: Udder depth (UD), Cistern depth (CD), Teat position (TP), Teat size (TS) and external udder measurements: Rear udder depth (RUD), Cistern depth (CDe), Teat length (TL) and Teat angle (TA) – 1275 linear assessments (381 ewes) and 1185 external udder measurements (355 ewes) were included in the analysis for each character of 9 genotypes. Nine breeds and genotypes were included in these experiments: purebred Improved Valachian (IV), Tsigai (T), Lacaune (LC) ewes, and IV and T crosses with genetic portion of Lacaune and East Friesian (EF) – 25 %, 50 % and 75 %. Primary data were processed using restricted maximum likelihood (REML) methodology and the multiple‑trait animal model, using programs REMLF90 and VCE 4.0. High genetic correlations were found between UD and RUD (0.86), CD and CD(e) (0.93), TP and TA (0.90), TS and TL (0.94). The highest heritabilities were estimated for exact measurements of TL and CD (0.35–0.39) and subjectively assessed TA and TS (0.32 – 0.33).

scholarly journals Genetic parameters for weight, morphometry and oviposition of Africanized honeybee queens using simulated data

2020 ◽  
Vol 72 (5) ◽  
pp. 1959-1964
Author(s):  
E.H. Martins ◽  
G. Tarôco ◽  
G.A. Rovadoscki ◽  
M.H.V. Oliveira ◽  
G.B. Mourão ◽  
...  
Keyword(s):  
Variance Components ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Simulated Data ◽  
Real Data ◽  
Biological Data ◽  
Likelihood Method ◽  
Phenotypic Correlations ◽  
Genetic Evaluations ◽  
The Impact

ABSTRACT This study aimed to estimate genetic parameters for simulated data of body weight (BW), abdominal width (AW), abdominal length (AL), and oviposition. Simulation was performed based on real data collected at apiaries in the region of Campo das Vertentes, Minas Gerais, Brazil. Genetic evaluations were performed using single- and two-trait models and (co)variance components were estimated by the restricted maximum likelihood method. The heritability for BW, AW, AL and oviposition were 0.54, 0.47, 0.31 and 0.66, respectively. Positive genetic correlations of high magnitude were obtained between BW and AW (0.80), BW and oviposition (0.69), AW and oviposition (0.82), and AL and oviposition (0.96). The genetic correlations between BW and AL (0.11) and between AW and AL (0.26) were considered moderate and low. In contrast, the phenotypic correlations were positive and high between BW and AW (0.97), BW and AL (0.96), and AW and AL (0.98). Phenotypic correlations of low magnitude and close to zero were obtained for oviposition with AL (0.02), AW (-0.02), and BW (-0.03). New studies involving these characteristics should be conducted on populations with biological data in order to evaluate the impact of selection on traits of economic interest.

scholarly journals Relationship between age at first start and racing performance in Polish Thoroughbreds and Arab horses

2010 ◽  
Vol 53 (6) ◽  
pp. 639-649
Author(s):  
M. Sobczynska
Keyword(s):  
Animal Model ◽  
Maximum Likelihood ◽  
Fixed Effects ◽  
Genetic Correlations ◽  
Point Of View ◽  
Square Root ◽  
Month Of Birth ◽  
Racing Performance ◽  
Performance Traits ◽  
And Performance

Abstract. Genetic and phenotypic parameters for age at first start (AFS) and performance traits were estimated for Polish Thoroughbred and Arab horses using restricted maximum likelihood (REML) with an animal model. The traits representing a horse’s racing performance were log of earnings (EA) and square root of number of starts (NS). Separate analyses per first racing season and whole career were carried out. The first racing season comprised 1 759 Thoroughbreds and 1 026 Arab horses. The racing results of whole racing career were available for 1 319 Thoroughbreds and 815 Arab horses. The model accounted for fixed effects of birth year, month of birth, sex and trainer. The average of AFS of Thoroughbreds was 933.2 days for first racing season and 935.1 for whole career. The same AFS was observed at first season and whole career (about 1 199 days) in Arab horses. Heritability estimates for AFS were rather low (0.15-0.21) . All genetic correlations for Arab horses between age and performance traits varied from moderate to high (from −0.25 to −0.85). For whole career of Thoroughbreds, the genetic correlations had opposite signs compared to those observed in Arabs. Genetic correlation between AFS and EA in first racing season was very low in Thoroughbreds (−0.07), whereas high between AFS and NS (−1); the corresponding values for Arab horses were −0.25 and −0.76. The opposite signs of phenotypic and genetic correlations (0.16 vs −1 and −0.24 vs 1 in first season and whole career, respectively) between AFS and NS in Thoroughbreds were observed. Phenotypic correlations between AFS and performance traits were close to zero for whole career while were rather low and moderate (−0.22 and −0.37) for first season in Arab horses. Delay of the first start of Thoroughbreds is favourable from the point of view of future racing performance in whole career and has no effect on earnings in the first racing season. Arab horses beginning their career at a young age are start frequently and earn more money then those beginning their career later.

scholarly journals Genetic analysis of udder score and milk traits in test day records of Sfakia dairy ewes

2002 ◽  
Vol 45 (1) ◽  
pp. 69-77 ◽  
Author(s):  
M. Volanis ◽  
A. Kominakis ◽  
E. Rogdakis
Keyword(s):  
Animal Model ◽  
Genetic Analysis ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Fat Percentage ◽  
Milk Traits ◽  
Dairy Ewes ◽  
Genetic And Phenotypic Correlations ◽  
Daily Milk Yield ◽  
Daily Milk

Abstract. A total of 4466 monthly test day records of 555 Greek Sfakia dairy ewes were used to estimate heritabilities as well as genetic and phenotypic correlations for udder score (US), average daily milk yield (MY), fat percentage (FC) and protein percentage (PC) of milk. Genetic parameters were estimated with a multitrait animal model with correlated residuals. Heritabilities were between 0.17 and 0.24, 0.41 and 0.47, 0.32 and 0.52 and 0.44 and 0.55, for test day US, MY, FC and PC, respectively. Within traits, genetic correlations between test days were between 0.54 and 0.57, 0.71 and 0.96, 0.79 and 0.99 and 0.85 and 0.99 for US, MY, FC and PC, respectively. Genetic correlations between milk traits and US were negative and of very low magnitude (−0.04 to −0.06). Genetic correlations between MY – FC and MY – PC were negative and of varying magnitude, from −0.37 to −0.52 and from −0.44 to −0.50, in the four test days, respectively. Fat and protein percentages were found to be highly, positively, correlated.

scholarly journals Realized Sampling Variances of Estimates of Genetic Parameters and the Difference Between Genetic and Phenotypic Correlations

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson
Keyword(s):  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Phenotypic Correlation ◽  
Parameter Estimates ◽  
Sampling Variance ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Heritability Estimates

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.

Genetic parameters of Barki sheep raised under semi-arid conditions

1969 ◽  
Vol 11 (3) ◽  
pp. 361-367 ◽  
Author(s):  
M. H. Fahmy ◽  
E. Salah E. Galal ◽  
Y. S. Ghanem ◽  
S. S. Khishin
Keyword(s):  
Genetic Parameters ◽  
Genetic Correlations ◽  
Research Station ◽  
Phenotypic Correlations ◽  
Arid Conditions ◽  
Body Weights ◽  
Genetic And Phenotypic Correlations ◽  
Fleece Weight ◽  
Semi Arid ◽  
Desert Research

SUMMARYRecords on 695 lambs were collected over a period of 5 years from 1961/62 to 1965/66, at Ras El-Hekma Desert Research Station, 230 km west of Alexandria. The characters studied were birth, weaning and yearling body weights, pre- and post-weaning daily gains and greasy fleece weight.Birth, 120-day and 365-day body weights were 3·4, 18·2 and 33·4 kg respectively. Greasy fleece weight at 16 months of age was 3·29 kg. Heritability estimates of birth, weaning, yearling weights, pre- and post-weaning daily gains and greasy fleece weight were 0·22, 0·45, 0·41,0·45 and 0·29 respectively. Genetic and phenotypic correlations between birth, weaning and yearling weights were all positive and significant. Genetic correlations between fleece weight and body characteristics were negative and low.

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