scholarly journals Prevalence and breeding values of elbow dysplasia in the Estrela mountain dog

2013 ◽  
Vol 58 (No. 9) ◽  
pp. 484-490 ◽  
Author(s):  
S. Alves-Pimenta ◽  
B. Colaco ◽  
AM Silvestre ◽  
MM Ginja
Keyword(s):  
Hip Dysplasia ◽  
Mass Selection ◽  
Genetic Trend ◽  
Genetic Progress ◽  
Breeding Values ◽  
Elbow Dysplasia ◽  
Low Mass ◽  
The Mean ◽  
Dog Breed ◽  
Genetic Trends

The aims of this study were to determine the prevalence and heritability of elbow dysplasia in the Estrela mountain dog breed, to investigate genetic trends over the last 20 years (1990–2009) and to evaluate the association of individual records with breeding values. The elbows of 351 Estrela mountain dogs were examined using the flexed mediolateral radiographic view and evaluated using the International Elbow Working Group scoring system. Heritability and breeding values were estimated using a linear model. Elbow Dysplasia was found in 16.5% (59/351) of the dogs; males (27%, 34/127) were more affected than females (11%, 24/224) (P < 0.05). The heritability was very low (0.065) and the genetic trend showed a slight positive slope with an improvement in 2004 and 2005. The mean breeding values in elbow dysplasia grades were different but the overlap among grades was very pronounced. The prevalence and heritability of elbow dysplasia in the breed are thus low. Mass selection using individual phenotypes may not be effective. Elbow dysplasia genetic trends are similar to trends for hip dysplasia and passive hip laxity, so the use of selection against hip dysplasia may also result in genetic progress for elbow dysplasia.  

scholarly journals Genetic variances, trends and mode of inheritance for hip and elbow dysplasia in Finnish dog populations

2002 ◽  
Vol 75 (2) ◽  
pp. 197-207 ◽  
Author(s):  
K. Mäki1 ◽  
A. F. Groen ◽  
A.-E. Liinamo ◽  
M. Ojala
Keyword(s):  
Fixed Effects ◽  
Hip Dysplasia ◽  
Time Dependent ◽  
German Shepherd ◽  
Breeding Values ◽  
Frequency Distributions ◽  
Genetic Variances ◽  
Elbow Dysplasia ◽  
Mode Of Inheritance ◽  
Genetic Trends

AbstractThe aims of this study were to assess genetic variances, trends and mode of inheritance for hip and elbow dysplasia in Finnish dog populations. The influence of time-dependent fixed effects in the model when estimating the genetic trends was also studied. Official hip and elbow dysplasia screening records of 42 421 dogs from seven breeds were analysed with REML. To investigate the mode of inheritance of hip and elbow dysplasia, trait distributions, genetic variances and regressions of offspring phenotypes on parental predicted breeding values were studied separately in males and in females. Genetic trends for hip dysplasia between the years 1983 and 1998 were favourable only in the Rottweiler. In elbow dysplasia, the trends were favourable after the year 1992 in all the four breeds studied but the overall changes were small. The reason for this seemed to be negligible selection pressure against these traits. Time-dependent fixed effects in the model had an influence on the estimated genetic trends, resulting either in a more negative or more positive genetic trend compared with the model from which the time-dependent effects were removed. Mitochondrial or sex-linked inheritance did not seem likely in the expression of hip and elbow dysplasia in the populations studied. Regression coefficients of offspring phenotypes on estimated parental breeding values were approximately equal to their expected value in a situation with equal parental contribution. Furthermore, the phenotypic frequency distributions of hip and elbow dysplasia grades were similar among males and females in each breed studied. No indication of major genes was found in the offspring frequency distributions within individual sires. According to these Finnish data, mode of inheritance for both hip and elbow dysplasia is polygenic (quantitative) with equal expression of the genes from both parents, although the estimates of heritability for hip dysplasia in the Rough Collie and for elbow dysplasia in the German Shepherd and the Golden Retriever were somewhat different in males compared with females.

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.

scholarly journals Genetic parameters and trends for reproductive traits in Blanco Orejinegro cattle from Colombia

2021 ◽  
Vol 42 (4) ◽  
pp. 2523-2538
Author(s):  
Sindy Liliana Caivio-Nasner ◽  
◽  
Albeiro López-Herrera ◽  
Luis Gabriel González-Herrera ◽  
Juan Carlos Rincón Flórez ◽  
...  
Keyword(s):  
Inbreeding Depression ◽  
Genetic Parameters ◽  
Environmental Influence ◽  
Cattle Breed ◽  
Heritability Estimate ◽  
Reproductive Traits ◽  
Genetic Trend ◽  
Genetic Progress ◽  
Estimated Breeding Values ◽  
Genetic Trends

The Colombian creole cattle breed Blanco Orejinegro (BON) is an important zoogenetic resource, but there is little knowledge about the genetic parameters and trends of its reproductive traits. Therefore, the aim of this study was to estimate parameters for the reproductive traits calving interval (CI), age at first calving (AFC), gestation duration (GD) and genetic trends for CI in the BON breed. Genealogy information from 7,799 animals was used, and employing the MTDFREML program, the components of the variance, heritability (h2), repeatability (rep), and estimated breeding values (EBV) for CI (n=3308), AFC (n=729), and GD (n=306) were estimated, in addition to the inbreeding coefficient (F) of the population. Genetic trends were established through linear regression using R software. Finally, the animals were classified as inbred (F > 0) and noninbred (F=0), and the effect of inbreeding on reproductive performance was established through a generalized linear model using the R program. An average F value of 4.41%±0.06 was observed. The h2 for CI was 0.11±0.03 with a rep of 0.15±0.04; for AFC, h2 was 0.00±0.05; and for GD, h2 was 0.00±0.08. The genetic trend for CI was -0.01 days/year. Finally, for CI, inbreeding depression was evident; this trait increased when inbreeding increased. These results indicate an important environmental influence on reproductive traits. The heritability estimate for CI suggests that little genetic progress could be achieved through selection. The evidence of inbreeding depression raises the need to control inbreeding to conserve this genetic resource.

scholarly journals AlphaPart—R implementation of the method for partitioning genetic trends

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Jana Obšteter ◽  
Justin Holl ◽  
John M. Hickey ◽  
Gregor Gorjanc
Keyword(s):  
Genetic Gain ◽  
R Package ◽  
Breeding Programme ◽  
Genetic Trend ◽  
Breeding Values ◽  
Poultry Breeding ◽  
Breeding Programmes ◽  
Estimated Breeding Values ◽  
The Relationship ◽  
Genetic Trends

Abstract Background In this paper, we present the AlphaPart R package, an open-source implementation of a method for partitioning breeding values and genetic trends to identify the contribution of selection pathways to genetic gain. Breeding programmes improve populations for a set of traits, which can be measured with a genetic trend calculated from estimated breeding values averaged by year of birth. While sources of the overall genetic gain are generally known, their realised contributions are hard to quantify in complex breeding programmes. The aim of this paper is to present the AlphaPart R package and demonstrate it with a simulated stylized multi-tier breeding programme mimicking a pig or poultry breeding programme. Results The package includes the main partitioning function AlphaPart, that partitions the breeding values and genetic trends by pre-defined selection paths, and a set of functions for handling data and results. The package is freely available from the CRAN repository at http://CRAN.R-project.org/package=AlphaPart. We demonstrate the use of the package by partitioning the nucleus and multiplier genetic gain of the stylized breeding programme by tier-gender paths. For traits measured and selected in the multiplier, the multiplier selection generated additional genetic gain. By using AlphaPart, we show that the additional genetic gain depends on accuracy and intensity of selection in the multiplier and the extent of gene flow from the nucleus. We have proven that AlphaPart is a valuable tool for understanding the sources of genetic gain in the nucleus and especially the multiplier, and the relationship between the sources and parameters that affect them. Conclusions AlphaPart implements the method for partitioning breeding values and genetic trends and provides a useful tool for quantifying the sources of genetic gain in breeding programmes. The use of AlphaPart will help breeders to improve genetic gain through a better understanding of the key selection points that are driving gains in each trait.

scholarly journals Genetic parameter and genetic trend estimates for reproductive traits in Wistar rats

2020 ◽  
Vol 72 (4) ◽  
pp. 1479-1486
Author(s):  
G. Taroco ◽  
J.T. Paiva ◽  
G.B. Mourão ◽  
J.B.S. Ferraz ◽  
E.C. Mattos ◽  
...  
Keyword(s):  
Genetic Correlation ◽  
Wistar Rats ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Wistar Rat ◽  
The Other ◽  
Genetic Trend ◽  
Genetic Progress ◽  
Genetic Trends

ABSTRACT The aim of this study was to estimate genetic parameters and genetic trends for reproductive traits in Wistar rats. A total of 1,167 data records from 283 females over six generations of monogamous mating pairs was used. Heritability and genetic correlation were estimated through Bayesian inference and genetic trends were calculated by linear regression of breeding values over generations. Heritability estimates for litter size at birth (LS), calving interval (CI), pup mortality (PM) and maternal cannibalism (CAN) presented low magnitude, ranging from 0.01 to 0.13. CAN presented high and positive genetic correlation with LS and PM (0.77 and 0.78, respectively). On the other hand, all the other estimated genetic correlations were not significant. Genetic trend was positive for LS (+0.0900 pups per generation), and negative for PM and CAN (-1.0085 and -0.5217 pups per generation, respectively). For CI the genetic trend was not significant. It is recommended to increase selection intensity on dams in this Wistar rat population in order to accelerate the genetic progress.

scholarly journals AlphaPart - R implementation of the method for partitioning genetic trends

2020 ◽  
Author(s):  
Jana Obšteter ◽  
Justin Holl ◽  
John M. Hickey ◽  
Gregor Gorjanc
Keyword(s):  
Gene Flow ◽  
Open Source ◽  
Open Source Software ◽  
Genetic Gain ◽  
R Package ◽  
Genetic Trend ◽  
Breeding Values ◽  
Breeding Programmes ◽  
Estimated Breeding Values ◽  
Genetic Trends

AbstractBackgroundIn this paper we present the AlphaPart R package, an open-source software that implements a method for partitioning breeding values and genetic trends to identify sources of genetic gain. Breeding programmes improve populations for a set of traits, which can be measured with a genetic trend calculated from averaged year of birth estimated breeding values of selection candidates. While sources of the overall genetic gain are generally known, their realised contributions are hard to quantify in complex breeding programmes. The aim of this paper is to present the AlphaPart R package and demonstrate it with a simulated pig breeding example.ResultsThe package includes the main partitioning function AlphaPart, that partitions the breeding values and genetic trends by analyst defined paths, and a set of functions for handling data and results. The package is freely available from CRAN repository at http://CRAN.R-project.org/package=AlphaPart. We demonstrate the use of the package by examining the genetic gain in a pig breeding example, in which the multiplier achieved higher breeding values than the nucleus for traits measured and selected in the multiplier. The partitioning analysis revealed that these higher values depended on the accuracy and intensity of selection in the multiplier and the extent of gene flow from the nucleus. For traits measured only in the nucleus, the multiplier achieved comparable or smaller genetic gain than the nucleus depending on the amount of gene flow.ConclusionsAlphaPart implements a method for partitioning breeding values and genetic trends and provides a useful tool for quantifying the sources of genetic gain in breeding programmes. The use of AlphaPart will help breeders to better understand or improve their breeding programmes.

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.

Genetic trends of body weight and some scanning traits of Karayaka lambs

2018 ◽  
Author(s):  
Zafer Ulutaº ◽  
Yüksel Aksoy ◽  
Aziz ªahin ◽  
Emre ªirin ◽  
Ugur ªen ◽  
...  
Keyword(s):  
Body Weight ◽  
Selective Breeding ◽  
Experimental Period ◽  
Breeding Program ◽  
Genetic Trend ◽  
Breeding Values ◽  
Selection Program ◽  
Increase Productivity ◽  
Genetic Trends

This investigation was conducted to estimate the breeding values and genetic trends for body weight (BW), scanning fat depth (SFD) and scanning muscle depth (SMD) of Karayaka lambs (n= 1059) at 140 ± 3.36 day of age. Experiments were conducted in a nucleus flock of Karayaka sheep under a selective breeding program to increase productivity at research farm of Gaziosmanpasa University between the years 2006 - 2011. Breeding values were estimated with ASREML software. While genetic trend for BW and SMD showed a smooth ascending trend, SFD exhibited a descending trend throughout the experimental period. The genetic trend for BW, SFD and SMD of Karayaka lambs were observed as 0.433 kg / year, - 0.00686 mm / year and 0.00786 mm / year, respectively. The results showed that applying of a selection program on BW, SMD and SFD characteristics would increase BW and SMD values and decrease SFD value in Karayaka lambs.

Joint estimation of (co) variance components and breeding values for mean and dispersion of days from calving to first service in Holstein cow

2017 ◽  
Vol 57 (4) ◽  
pp. 760 ◽  
Author(s):  
Heydar Ghiasi ◽  
Majbritt Felleki
Keyword(s):  
Standard Deviation ◽  
Genetic Correlation ◽  
Additive Genetic Variance ◽  
Joint Estimation ◽  
Breeding Value ◽  
Genetic Trend ◽  
Breeding Values ◽  
The Mean ◽  
Estimated Breeding Values ◽  
Genetic Standard Deviation

The present study explored the possibility of selection for uniformity of days from calving to first service (DFS) in dairy cattle. A double hierarchical generalised linear model with an iterative reweighted least-squares algorithm was used to estimate covariance components for the mean and dispersion of DFS. Data included the records of 27 113 Iranian Holstein cows (parity, 1–6) in 15 herds from 1981 to 2007. The estimated additive genetic variance for the mean and dispersion were 32.25 and 0.0139; both of these values had low standard errors. The genetic standard deviation for dispersion of DFS was 0.117, indicating that decreasing the estimated breeding value of dispersion by one genetic standard deviation can increase the uniformity by 12%. A strong positive genetic correlation (0.689) was obtained between the mean and dispersion of DFS. This genetic correlation is favourable since one of the aims of breeding is to simultaneously decrease the mean and increase the uniformity of DFS. The Spearman rank correlations between estimated breeding values in the mean and dispersion for sires with a different number of daughter observations were 0.907. In the studied population, the genetic trend in the mean of DFS was significant and favourable (–0.063 days/year), but the genetic trend in the dispersion of DFS was not significantly different from zero. The results obtained in the present study indicated that the mean and uniformity of DFS can simultaneously be improved in dairy cows.

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