scholarly journals ESTIMATE OF GENETIC COMPONENTS OF BIRTH WEIGHT USING MULTI-BREED MODELS WITH DIFFERENT PEDIGREE STRUCTURES IN MESTIZO SHEEP

2021 ◽  
pp. 143-149
Author(s):  
Fernando Amarilho-Silveira ◽  
Nelson José Laurino Dionello ◽  
Ali Willian Canaza-Cayo
Keyword(s):  
Birth Weight ◽  
Likelihood Method ◽  
Pedigree Information ◽  
Residual Variance ◽  
Additive Effects ◽  
Pedigree Structure ◽  
Genetic Components ◽  
Restricted Likelihood ◽  
Maternal Heritability ◽  
Weight Trait

The objectives of this paper were to verify the influence of the multi-breed model and pedigree structure in the estimates of the genetic components to birth weight in a mestizo herd. Using 1234 birth weight records in two ways, one dataset with complete pedigree information (n = 1028) and another with incomplete pedigree information (n = 1234). The pedigree was composed for 10 sires, 366 and 448 dams for complete and incomplete pedigree, respectively. Used for analysis the maximum restricted likelihood method about the animal model, considering the birth weight trait, for a dataset with or not complete pedigree, used the WOMBAT program. The direct heritability coefficients in both datasets did not present large difference, 0.06 and 0.09 to best models in the complete and incomplete pedigree, respectively. However, in the incomplete pedigree, the maternal heritability was 0.29. The residual variance, which on the best model of the dataset with complete pedigree presented 0.51 and 0.35 for the best model of the dataset with incomplete pedigree. Concluding, we find the influence of de multi-breed model only in the dataset with complete pedigree, that considered the direct and breed effects. In the dataset with incomplete pedigree, the better model was that considered the direct and maternal additive effects.

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 Genetic components of birth weight of texel sheep reared in extensive system

2017 ◽  
Vol 40 ◽  
pp. 36481
Author(s):  
Fernando Amarilho-Silveira ◽  
Nelson José Laurino Dionello ◽  
Gilson De Mendonça ◽  
Jaqueline Freitas Motta ◽  
Tiago Albandes Fernandes ◽  
...  
Keyword(s):  
Birth Weight ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Likelihood Method ◽  
Phenotypic Variance ◽  
Genetic Trend ◽  
Extensive System ◽  
Genetic Components ◽  
Best Fit ◽  
Variance Explained

This study aimed to estimate the components of (co)variance, genetic and phenotypic parameters and trends for birth weight. We used 783 birth weight records, between 2012 to 2016, of Texel sheep reared in extensive system. The components of (co)variance and the genetic parameters were estimated using six different animal models, using the restricted maximum likelihood method (REML). The model that best fit the data was Model 3, with estimates of direct additive genetic variance of 0.004, maternal permanent environment variance of 0.164, heritability coefficient of 0.011 and phenotypic variation attributed to the maternal permanent environment of 0.394. For the genetic trend, we observed a genetic gain of 0.413% and for the phenotypic trend, a phenotypic gain of 0.159 kg, between 2012 and 2016 were found. Estimates of direct heritability and proportion of the phenotypic variance explained by the maternal permanent environment presented lower and higher values, respectively, in comparison to other studies. For trends, both genetic and phenotypic, there were gains in birth weight between 2012 and 2016. 

scholarly journals Using the difference in actual and expected calf liveweight relative to its dam liveweight as a statistic for interherd and intraherd benchmarking and genetic evaluations1

2019 ◽  
Vol 97 (12) ◽  
pp. 4737-4745 ◽  
Author(s):  
Noirin McHugh ◽  
Ross D Evans ◽  
Donagh P Berry
Keyword(s):  
Genetic Variability ◽  
Production Systems ◽  
Management Strategies ◽  
Population Based ◽  
Multiple Regression Model ◽  
Residual Variance ◽  
Genetic Progress ◽  
The Difference ◽  
Simple Ratio ◽  
Maternal Heritability

Abstract The importance of improving the efficiency of beef production systems using both genetic and management strategies has long been discussed. Despite the contribution of the mature beef herd to the overall cost of production in the sector as a whole, most strategies for improving (feed) efficiency have focused on the growing animal. The objective of the present study was to quantify the phenotypic and genetic variability in several novel measures that relate the weight of a calf to that of its dam and vice versa. Two novel residual traits, representing the deviation in calf weight relative to its expectation from the population based on its dam’s weight (DIFFcalf) or the deviation in the weight of the dam relative to its expectation from the population based on its calf’s weight (DIFFdam), were calculated while simultaneously accounting for some nuisance factors in a multiple regression model. Four supplementary traits were also calculated, namely, 1) the deviation in calf weight from its expectation expressed relative to the weight of the dam (DIFFcalf_ratio), 2) the deviation in dam weight from its expectation relative to the weight of the dam (DIFFdam_ratio), 3) DIFFcalf-DIFFdam, and 4) the simple ratio of calf weight to its dam’s weight (RATIOcalfdam). Genetic and residual variance components for each of the 6 traits were estimated using animal–dam linear mixed models. The phenotypic SD for DIFFcalf was 42 kg and, when expressed relative to the weight of the dam (i.e., DIFFcalf_ratio), was 0.07. The genetic SD for DIFFcalf and DIFFcalf_ratio was 16.66 kg and 0.02, respectively. The direct and maternal heritability estimated for DIFFcalf was 0.28 (SE = 0.04) and 0.11 (SE = 0.02), respectively, and for DIFFcalf_ratio was 0.24 (SE = 0.04) and 0.17 (SE = 0.03), respectively. The genetic SD for DIFFdam was 47.09 kg; the direct heritability was 0.50 (SE = 0.03), and the dam repeatability was 0.75 (SE = 0.01). The genetic SD for RATIOcalfdam was 0.03; the direct and maternal heritability was 0.24 (SE = 0.04) and 0.24 (SE = 0.03), respectively. The suggested traits outlined in the present study provide useful metrics for benchmarking dam–calf efficiency; in addition, the genetic variability detected in these traits suggest genetic progress for more efficient dam–calf pairs is indeed possible.

scholarly journals Degree of multicollinearity and variables involved in linear dependence in additive-dominant models

2012 ◽  
Vol 47 (12) ◽  
pp. 1743-1750 ◽  
Author(s):  
Juliana Petrini ◽  
Raphael Antonio Prado Dias ◽  
Simone Fernanda Nedel Pertile ◽  
Joanir Pereira Eler ◽  
José Bento Sterman Ferraz ◽  
...  
Keyword(s):  
Birth Weight ◽  
Linear Dependence ◽  
Correlation Matrix ◽  
Condition Index ◽  
Additive Effects ◽  
Variance Inflation Factor ◽  
Explanatory Variables ◽  
Scrotal Circumference ◽  
Natural Connection ◽  
Inflation Factor

The objective of this work was to assess the degree of multicollinearity and to identify the variables involved in linear dependence relations in additive-dominant models. Data of birth weight (n=141,567), yearling weight (n=58,124), and scrotal circumference (n=20,371) of Montana Tropical composite cattle were used. Diagnosis of multicollinearity was based on the variance inflation factor (VIF) and on the evaluation of the condition indexes and eigenvalues from the correlation matrix among explanatory variables. The first model studied (RM) included the fixed effect of dam age class at calving and the covariates associated to the direct and maternal additive and non-additive effects. The second model (R) included all the effects of the RM model except the maternal additive effects. Multicollinearity was detected in both models for all traits considered, with VIF values of 1.03 - 70.20 for RM and 1.03 - 60.70 for R. Collinearity increased with the increase of variables in the model and the decrease in the number of observations, and it was classified as weak, with condition index values between 10.00 and 26.77. In general, the variables associated with additive and non-additive effects were involved in multicollinearity, partially due to the natural connection between these covariables as fractions of the biological types in breed composition.

scholarly journals Parámetros genéticos y tendencias para características de crecimiento en el ganado criollo sanmartinero en los Llanos Orientales de Colombia

2009 ◽  
Vol 10 (2) ◽  
pp. 196 ◽  
Author(s):  
Rodrigo Martínez ◽  
Guillermo Onofre ◽  
Nelson Polanco
Keyword(s):  
Animal Model ◽  
Birth Weight ◽  
Environmental Effects ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Change ◽  
Direct Effects ◽  
Creole Cattle ◽  
Maternal Heritability ◽  
Daily Gain

<p>El objetivo de este trabajo fue estimar parámetros genéticos para características de crecimiento y la tendencia de sus valores genéticos en una población de la raza bovina criolla sanmartinero, localizada en el departamento del Meta, Colombia. Se utilizó un modelo animal con efectos directos, maternos y de ambiente permanente y se analizaron las características peso al nacimiento (PN), peso al destete (PD) (ajustado a 240 d.), peso a los 16 meses (P16m), ganancia diaria de peso al destete (GPD) y ganancia diaria de peso desde el destete a los 16 meses (GP16m). Se analizaron 2.812 registros productivos de animales y se encontraron valores de heredabilidad directa moderados, variando desde 0,16 hasta 0,37 para GP16m y GPD respectivamente. Los valores de heredabilidad directa siempre fueron mayores que los de heredabilidad materna y los efectos de ambiente permanente variaron entre 0,024 ± 0,033 para PN hasta 0,067 ± 0,041 para P16m; los valores de repetibilidad fueron superiores para las características de PD (0,41) y GPD (0,37). Los valores genéticos anuales promedio para los efectos directos presentaron en general valores positivos, lo que muestra una tendencia creciente aunque con una alta variación a través de los años; por su parte, los valores genéticos maternos anuales promedio presentaron valores cercanos a cero, aunque en general su tendencia también fue creciente. A pesar de tratarse de un núcleo de conservación, donde no se ha dado selección para estas características, se encontró una tendencia genética que indica un cambio genético positivo.  </p><p> </p><p><strong>Genetic parameters and trends for growth traits in creole cattle sanmartinero in the eastern savannas in Colombia</strong>  </p><p>The aim of this work was to estimate the genetic parameters for growth traits and the tendency of their genetic values in a population of Bovine Creole cattle Sanmartinero, located in Meta, Colombia. Was used an animal model with direct and maternal effects as well as a permanent environmental effects and were analyzed birth weight, weaning weight, (adjusted at 240 d), weight at 16 months, weaning daily gain, and daily gain at 16 months. Were analyzed a total of 2812 productive records from animals and were found direct heritability moderate values, ranging between from 0.16 to 0.3 for GP16m and GP respectively. The direct heritability values always were higher than the maternal heritability values and the permanent environmental effects ranged between 0.024 ± 0.033 for PN until 0.067 ± 0.041 for P16m, but the repeatability values were higher for PD (0.41) and GPD (0.37) traits. With reference to the tendency of average yearly genetic values for direct effects, always displayed positive values and a increase tendency however a high variation between the years were found, conversely to the genetic maternal values than displayed generally values near to zero, but their tendency also was to increase. Is noteworthy than in spite of to be a conservation herd, than do not has been used for selection programs for those traits, was found a genetic tendency that suggest a positive genetic change. </p>

scholarly journals Two variance component model improves genetic prediction in family data sets

2015 ◽  
Author(s):  
George Tucker ◽  
Po-Ru Loh ◽  
Iona M MacLeod ◽  
Ben J Hayes ◽  
Michael E Goddard ◽  
...  
Keyword(s):  
Variance Component ◽  
Mixed Model ◽  
Component Model ◽  
Pedigree Information ◽  
Variance Component Model ◽  
Data Sets ◽  
Sample Sizes ◽  
Pedigree Structure ◽  
Genetic Prediction ◽  
Current Sample

Genetic prediction based on either identity by state (IBS) sharing or pedigree information has been investigated extensively using Best Linear Unbiased Prediction (BLUP) methods. Such methods were pioneered in the plant and animal breeding literature and have since been applied to predict human traits with the aim of eventual clinical utility. However, methods to combine IBS sharing and pedigree information for genetic prediction in humans have not been explored. We introduce a two variance component model for genetic prediction: one component for IBS sharing and one for approximate pedigree structure, both estimated using genetic markers. In simulations using real genotypes from CARe and FHS family cohorts, we demonstrate that the two variance component model achieves gains in prediction r2 over standard BLUP at current sample sizes, and we project based on simulations that these gains will continue to hold at larger sample sizes. Accordingly, in analyses of four quantitative phenotypes from CARe and two quantitative phenotypes from FHS, the two variance component model significantly improves prediction r2 in each case, with up to a 20% relative improvement. We also find that standard mixed model association tests can produce inflated test statistics in data sets with related individuals, whereas the two variance component model corrects for inflation.

Genetic variation and responses in reproductive performance of sows in lines selected for growth rate under restricted feeding

2006 ◽  
Vol 82 (1) ◽  
pp. 7-12 ◽  
Author(s):  
N. H. Nguyen ◽  
C. P. McPhee ◽  
C. M. Wade
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Birth Weight ◽  
Food Intake ◽  
Reproductive Performance ◽  
Likelihood Method ◽  
Gestation Length ◽  
Daily Food Intake ◽  
Daily Food ◽  
Reproduction Traits

AbstractThe objective of this study was to examine genetic changes in reproduction traits in sows (total number born (TNB), number born alive (NBA), average piglet birth weight (ABW) and number of piglets weaned (NW), body weight prior to mating (MW), gestation length (GL) and daily food intake during lactation (DFI)) in lines of Large White pigs divergently selected over 4 years for high and low post-weaning growth rate on a restricted ration. Heritabilities and repeatabilities of the reproduction traits were also determined. The analyses were carried out on 913 litter records using average information-restricted maximum likelihood method applied to single trait animal models. Estimates of heritability for most traits were small, except for ABW (0·33) and MW (0·35). Estimates of repeatability were slightly higher than those of heritability for TNB, NBA and NW, but they were almost identical for ABW, MW, GL and DFI. After 4 years of selection, the high growth line sows had significantly heavier body weight prior to mating and produced significantly more piglets born alive with heavier average birth weight than the low line sows. There were, however, no statistical differences between the selected lines in TNB or NW. The lower food intake of high relative to low line sows during lactation was not significant, indicating that daily food intake differences found between grower pigs in the high and low lines (2·71 v. 2·76 kg/day, s.e.d. 0·024) on ad libitum feeding were not fully expressed in lactating sows. It is concluded that selection for growth rate on the restricted ration resulted in beneficial effects on important measures of reproductive performance of thea sows.

scholarly journals 31 Changes in genomic predictions when new data is included

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 7-8
Author(s):  
Jorge Hidalgo ◽  
Daniela Lourenco ◽  
Shogo Tsuruta ◽  
Stephen P Miller ◽  
Andre Garcia ◽  
...  
Keyword(s):  
Birth Weight ◽  
Extended Period ◽  
Pedigree Information ◽  
Population Parameters ◽  
Weaning Weight ◽  
Average Maximum ◽  
Standard Deviations ◽  
Chromosome Segments ◽  
Genomic Predictions

Abstract Persistence of genomic evaluations depends on the amount of data and population parameters. When the data are large enough to estimate nearly all chromosome segments (about 10,000 in Angus), the persistence can be high. Subsequently, the regular evaluations can be run less often, and indirect predictions based on backsolved SNP effects may be accurate over an extended period as full predictions. The objective of this study was to investigate changes in GEBV across monthly genomic evaluations in a large genotyped population. A dataset from American Angus that contained 8,186,503 records for birth weight, 8,881,124 for weaning weight, and 4,386,184 for post-weaning gain was used. A total of 10,129,980 animals born up to December of 2017 had pedigree information, of which 484,074 were genotyped. A truncated dataset kept animals that were born up to December of 2016 (Dec2016). To mimic a scenario where evaluations are run every 30 days, the 2017 data was added month by month and new GEBV were computed using ssGBLUP. Genomic predictions from the Dec2016 evaluation were contrasted to the monthly evaluations for all genotyped animals, genotyped animals with or without phenotypes, genotyped animals with or without new phenotypes after Dec2016 and for young genotyped animals (born in 2016, with no phenotypes or progeny). The average number of animals added by month was 26,225, with a larger concentration from January to April. The correlations between GEBV from Dec2016 and all the 12 consecutive evaluations were greater or equal than 0.99 in all cases. The average (maximum) changes for young animals from Dec2016 to January and December of 2017 ranged from 0.05 (0.25) to 0.10 (0.53) additive standard deviations. The same changes for animals with records past Dec2016 were from 0.05 (0.11) to 0.88 (1.59). Genomic evaluations have high persistence over a year; however, outliers show larger changes.

Relationships between pre-weaning growth, post-weaning growth and mature body size in Chios sheep

1990 ◽  
Vol 50 (2) ◽  
pp. 271-275 ◽  
Author(s):  
A. P. Mavrogenis ◽  
A. Constantinou
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Birth Weight ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Live Weight ◽  
Pedigree Information ◽  
Mature Weight ◽  
Chios Sheep ◽  
Birth Type

ABSTRACTThe study examined early measures of growth and their relationships with mature body size. Data on 792 purebred females of the Chios breed, born and reared on two experimental farms between 1978 and 1986, were analysed. Pedigree information and records on live weight at birth, at weaning, 105 days of age and at first and subsequent matings was recorded. There were flock-year differences for all traits studied (P < 0·01) and birth type was important for all traits except post-weaning growth rate. Dam lactation number had no significant effect on birth weight and pre-weaning growth rate, but it significantly affected all subsequent weights and post-weaning growth rate. Estimated heritabilities increased with age and ranged from 0·13 (s.e. 0·14) (birth weight) to 0·30 (s.e. 0·15) (mature weight). Genetic correlations were generally positive between weights and growth traits. Phenotypic correlations were positive and followed the pattern of the genetic correlations. The results suggest that selection for 105-day weight will result in increased mature weight.

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