Estimates of genetic parameters and genetic trends for production and reproduction traits in Iranian buffaloes (Bubalus bubalis)

2017 ◽  
Vol 57 (2) ◽  
pp. 216 ◽  
Author(s):  
Navid Ghavi Hossein-Zadeh
Keyword(s):  
Animal Model ◽  
Gibbs Sampling ◽  
Genetic Selection ◽  
Genetic Effect ◽  
Reproductive Traits ◽  
Bubalus Bubalis ◽  
Reproduction Traits ◽  
Estimate Variance ◽  
Direct Genetic Effect ◽  
Genetic Trends

Calving and milk production records from April 1992 to March 2012 comprising 5353 records of age at first calving (AFC), 2972 records of 305-days milk yield (MY) and 2349 records of interval between first and second calving (CI) from the first lactation buffaloes within 785 herds of Iran were analysed using a linear animal model to estimate variance components and heritability for these traits. A linear animal model including direct genetic effect was implemented by Gibbs sampling methodology. A single Gibbs sampling chain with 300 000 rounds was generated by the TM program. Genetic trends were obtained by regressing yearly mean estimates of breeding values on birth year. Posterior mean estimates of direct heritabilities for MY, AFC and CI were 0.46 ± 0.21, 0.20 ± 0.06 and 0.21 ± 0.14, respectively. The posterior means of direct genetic correlation between MY-AFC, MY-CI and AFC-CI were –0.31, 0.01 and –0.17, respectively. Estimates of direct genetic trends for MY, AFC and CI were negative and significant, and their corresponding values were –1.50 ± 0.05 (P < 0.0001), –0.04 ± 0.001 (P < 0.0001) and –0.02 ± 0.005 (P < 0.001), respectively. Medium to high direct heritability estimates for productive and reproductive traits would be due to higher additive genetic variances for these traits and implied that applicable genetic variations observed for productive and reproductive traits could be applied in designing future genetic selection plans for Iranian buffaloes.

Bayesian analysis of direct and maternal effects for birthweight in Iranian buffaloes using Gibbs sampling

2016 ◽  
Vol 56 (5) ◽  
pp. 859 ◽  
Author(s):  
Navid Ghavi Hossein-Zadeh
Keyword(s):  
Animal Model ◽  
Gibbs Sampling ◽  
Maternal Effects ◽  
Threshold Model ◽  
Genetic Selection ◽  
Genetic Effects ◽  
Phenotypic Variance ◽  
Environmental Variance ◽  
Selection Decisions ◽  
Estimate Variance

Calving records from April 1994 to March 2010 comprising 8570 calving events from the first three parities of 734 buffalo herds of Iran were analysed using a linear animal model to estimate variance components and heritability for birthweight. A linear animal model including direct and maternal genetic effects with covariance between them and maternal permanent environmental effect was implemented by Gibbs sampling methodology. A single Gibbs sampling chain with 500 000 rounds was generated by the Threshold Model program. Posterior means of direct and maternal heritabilities and repeatability for birthweight were 0.21, 0.15 and 0.23, respectively. Estimate of correlation between direct and maternal genetic effects for birthweight was –0.71. Also, the ratio of permanent environmental variance to phenotypic variance was 0.02. Along with the direct genetic effects, the contribution of maternal effects to the phenotypic variance of birthweight may provide producers with information to optimally use the reported estimates when making selection decisions. The results of this study indicated that exploitable genetic variation observed for birthweight could be considered in designing future selection programs for Iranian buffaloes and improvement in birthweight could be attained by genetic selection.

A note on heritability estimates for growth traits in male and female Romanov sheep

1993 ◽  
Vol 57 (2) ◽  
pp. 326-328 ◽  
Author(s):  
G. A. María ◽  
K. G. Boldman ◽  
L. D. van Vleck
Keyword(s):  
Animal Model ◽  
Birth Weight ◽  
Maximum Likelihood ◽  
Random Effects ◽  
Fixed Effects ◽  
Growth Traits ◽  
Genetic Effect ◽  
Male And Female ◽  
Males And Females ◽  
Direct Genetic Effect

A total of 1855 records were analysed using restricted maximum likelihood (REML) techniques to estimate heritabilities separately for males and females lambs on birth weight (BW), weaning weight (WW), 90-day weight (W90) and average daily gains birth to weaning (Cl) and weaning to 90 days (C2). An animal model including fixed effects of year × season, parity, litter size and rearing type; and random effects of direct genetic effect (h2D) and residual was applied. Estimates ofh2Dfor BWwere 048 (males) and 0·50 (females); for WW 0·35 (males) and 0·22 (females); for W90 0·21 (males) and 0·31 (females); for Cl 0·20 (males) and 0·25 (females); and for C2 0·18 (males) and 0·29 (females).

scholarly journals Prediction of genetic merit for growth rate in pigs using animal models with indirect genetic effects and genomic information

2020 ◽  
Vol 52 (1) ◽  
Author(s):  
Bjarke G. Poulsen ◽  
Birgitte Ask ◽  
Hanne M. Nielsen ◽  
Tage Ostersen ◽  
Ole F. Christensen
Keyword(s):  
Growth Rate ◽  
Animal Model ◽  
Genetic Effect ◽  
Predictive Performance ◽  
Genetic Effects ◽  
Relationship Matrix ◽  
Genomic Information ◽  
Indirect Genetic Effects ◽  
Group Members ◽  
Direct Genetic Effect

Abstract Background Several studies have found that the growth rate of a pig is influenced by the genetics of the group members (indirect genetic effects). Accounting for these indirect genetic effects in a selection program may increase genetic progress for growth rate. However, indirect genetic effects are small and difficult to predict accurately. Genomic information may increase the ability to predict indirect genetic effects. Thus, the objective of this study was to test whether including indirect genetic effects in the animal model increases the predictive performance when genetic effects are predicted with genomic relationships. In total, 11,255 pigs were phenotyped for average daily gain between 30 and 94 kg, and 10,995 of these pigs were genotyped. Two relationship matrices were used: a numerator relationship matrix ($${\mathbf{A}}$$ A ) and a combined pedigree and genomic relationship matrix ($${\mathbf{H}}$$ H ); and two different animal models were used: an animal model with only direct genetic effects and an animal model with both direct and indirect genetic effects. The predictive performance of the models was defined as the Pearson correlation between corrected phenotypes and predicted genetic levels. The predicted genetic level of a pig was either its direct genetic effect or the sum of its direct genetic effect and the indirect genetic effects of its group members (total genetic effect). Results The highest predictive performance was achieved when total genetic effects were predicted with genomic information (21.2 vs. 14.7%). In general, the predictive performance was greater for total genetic effects than for direct genetic effects (0.1 to 0.5% greater; not statistically significant). Both types of genetic effects had greater predictive performance when they were predicted with $${\mathbf{H}}$$ H rather than $${\mathbf{A}}$$ A (5.9 to 6.3%). The difference between predictive performances of total genetic effects and direct genetic effects was smaller when $${\mathbf{H}}$$ H was used rather than $${\mathbf{A}}$$ A . Conclusions This study provides evidence that: (1) corrected phenotypes are better predicted with total genetic effects than with direct genetic effects only; (2) both direct genetic effects and indirect genetic effects are better predicted with $${\mathbf{H}}$$ H than $${\mathbf{A}}$$ A ; (3) using $${\mathbf{H}}$$ H rather than $${\mathbf{A}}$$ A primarily improves the predictive performance of direct genetic effects.

scholarly journals Genetic effects on reproductive traits in Warmblood horses

2009 ◽  
Vol 89 (2) ◽  
pp. 215-218 ◽  
Author(s):  
A. Wolc ◽  
G. Torzynski ◽  
T. Szwaczkowski
Keyword(s):  
Key Words ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Genetic Effect ◽  
Reproductive Traits ◽  
Additive Genetic Effect ◽  
Reproductive Efficiency ◽  
Horse Breeding ◽  
Estimate Heritability ◽  
Genetic Trends

Reproductive efficiency is an important issue in horse breeding. However, almost no estimates of genetic parameters of reproductive traits in horses can be found in the literature. The objective of the study was to estimate heritability and genetic trends of foaling rate and number of reproductive seasons in Warmblood horses. The records of 3965 mares from six studs were analyzed. Mares were on average kept for 7.3 reproductive seasons with a foaling rate of 66%. Models included fixed effects of stud, period of birth, breed and random additive genetic effect. Heritability estimates were 0.12 for foaling rate and 0.17 for number of reproductive seasons. Key words: Heritability, reproduction, horse

Genetic evaluation of lamb performance in Outaouais Arcott and Suffolk sheep, their crosses and Canadian Arcott- or Hampshire-sired three-breed crosses

1996 ◽  
Vol 76 (1) ◽  
pp. 15-22 ◽  
Author(s):  
A. M. Shafto ◽  
G. H. Crow ◽  
R. J. Parker ◽  
W. M. Palmer ◽  
J. N. B. Shrestha ◽  
...  
Keyword(s):  
Animal Model ◽  
Genetic Effect ◽  
Genetic Effects ◽  
Unbalanced Data ◽  
Sheep Flock ◽  
Data Set ◽  
Significant Difference ◽  
Breed Crosses ◽  
Terminal Sire ◽  
Direct Genetic Effect

A crossbreeding study was used to assess the growth performance of the Outaouais Arcott and Suffolk breeds, their two breed crosses and specific three-breed crosses sired by either Canadian Arcott or Hampshire rams. In a sheep flock maintained under a semi-confinement management system, Suffolk lambs, weighing 3.8 kg at birth, were not significantly heavier than Canadian Arcott- or Hampshire-sired crossbred lambs. Lambs of the Outaouais breed were 26% lighter (P < 0.05) than those of the Suffolk breed, and their two breed crosses had birth weights between the two parental purebreds. The relative ranks among the breeds and their crosses had not changed by 42 d of age with lamb weights ranging from 10.6 to 12.6 kg. By 120 d of age the Canadian Arcott- and Hampshire-sired lambs weighed approximately 28–29 kg and were not significantly different in weight from the Outaouais and Suffolk breeds and their two breed crosses. Additive and maternal genetic effects m the Suffolk breed were significantly greater than in the Outaouais breed for birth weight by 12.9 and 12.6% respectively. By 42 d, no difference was detected between breeds for direct genetic effect. However, the maternal effect favoured the Suffolk breed by 15.8% (P < 0.05). By 120 d, the direct genetic effect was significantly greater in the Outaouais breed by 9.8%, but maternal genetic effects continued to favour the Suffolk breed by 12.5% (P < 0.05). Heterosis effects were generally small (< 3.1%) and not significant for lamb weights. The terminal sire breeds showed no significant difference between Canadian- and Hampshire-sired lamb weights. Generally, results obtained for two analyses (least squares model and multi-trait animal model) of the same data set were consistent. However, the animal model would be preferable when estimating parameters and breeding values from an unbalanced data set with unequal subclass frequencies. Key words: Lambs, weight, genetic effects, heterosis, animal model

scholarly journals Estimation of genetic parameters and breeding values for litter size in the first three parity of landrace sows

2016 ◽  
Vol 32 (3) ◽  
pp. 261-269 ◽  
Author(s):  
Dragomir Lukac ◽  
Vitomir Vidovic ◽  
Teodora Vasiljevic ◽  
Oliver Stankovic
Keyword(s):  
Animal Model ◽  
Genetic Parameters ◽  
Multivariate Analyses ◽  
Reproductive Traits ◽  
Phenotypic Variance ◽  
Breeding Values ◽  
The Third ◽  
Reproduction Traits ◽  
Genetic And Phenotypic Correlations ◽  
Estimated Breeding Values

The aim of this study was to estimate the genetic parameters and breeding values for reproduction traits of Landrace sows in the first three parities by Animal model. Records of 2238 first parity; 2125 second parity and 1872 third parity Landrace sows farrowing between 2007 and 2012 were included in the analysis. The traits included in the analyses were total pigs born (TB), number of pigs born alive (NBA), number of pigs weaned (NW) and litter weaning weight (LW) in the parities. The genetic parameters were estimated using a multivariate analyses Animal model using REML procedure. Estimates of heritability for TB were 0.03, 0.05 and 0.18, for NBA were 0.04, 0.02 and 0.17, for NW were 0.08, 0.08 and 0.01 and for LW were 0.09, 0.11 and 0.03 for parities 1 to 3. Genetic and phenotypic variance were increased from the first to the third parity. Between the majorities of studied reproductive traits were the recorded positive genetic and phenotypic correlations, except between LW and other analyzed properties where they recorded a high correlation negative in third parity. Means of estimated breeding values of reproductive traits from first parity to third parity was indecreased.

Bayesian estimates of genetic relationship between calving difficulty and productive and reproductive performance in Holstein cows

2018 ◽  
Vol 58 (5) ◽  
pp. 785 ◽  
Author(s):  
Navid Ghavi Hossein-Zadeh ◽  
Mohammad Hossein Salimi ◽  
Abdol Ahad Shadparvar
Keyword(s):  
Animal Models ◽  
Reproductive Performance ◽  
Genetic Effect ◽  
Reproductive Traits ◽  
Calving Interval ◽  
Posterior Mean ◽  
Days Open ◽  
Fat Yield ◽  
Direct Genetic Effect ◽  
Calving Difficulty

The objective of present study was to estimate genetic correlations between calving difficulty and productive and reproductive traits in Iranian Holsteins. Calving records from the Animal Breeding Center of Iran, collected from 1991 to 2011 and comprising 183 203 first-calving events of Holstein cows from 1470 herds were included in the dataset. Threshold animal models included direct genetic effect (Model 1) or direct and maternal genetic effects with covariance between them (Model 2) were fitted for the genetic analysis of calving difficulty. Also, linear animal models including direct genetic effect were fitted for the genetic analysis of productive and reproductive performance traits. A set of linear-threshold bivariate models was used for obtaining genetic correlation between calving difficulty and other traits. All analyses were implemented by Bayesian approach via Gibbs sampling methodology. A single Gibbs sampling chain with 300 000 rounds was generated by the TM program. Posterior mean estimates of direct heritabilities for calving difficulty were 0.056 and 0.066, obtained from different models. Also, posterior mean estimate of maternal heritability for this trait was 0.018. Estimate of correlation between direct and maternal genetic effects for calving difficulty was negative (–0.44). Posterior mean estimates of direct heritabilities for milk yield, fat yield, protein yield, days from calving to first service, days open and first calving interval were 0.257, 0.188, 0.235, 0.034, 0.042 and 0.050 respectively. The posterior means of direct genetic correlation between calving difficulty and milk yield, fat yield, protein yield, days from calving to first service, days open and first calving interval were low and equal to –0.135, 0.030, –0.067, –0.010, –0.075 and –0.074 respectively. The results of the current study indicated that exploitable genetic variation in calving difficulty, productive and reproductive traits could be applied in designing future genetic selection plans for Iranian Holsteins.

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&nbsp;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&rsquo;s permanent environment. Heritability for melanoma occurrence was estimated for LM &ndash; 0.09, for TM &ndash; 0.27, and for TMb &ndash; 0.11. The coefficient of repeatability was estimated for LM &ndash; 0.77, for TM &ndash; 0.90, and for TMb &ndash; 0.99. The values of the Pearson&rsquo;s correlation coefficient and Spearmen&rsquo;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. &nbsp;

Egg weight and reproduction traits in laying hens: estimation of direct and maternal genetic effects using Bayesian approach via Gibbs sampling

2000 ◽  
Vol 70 (1) ◽  
pp. 9-16 ◽  
Author(s):  
A. Sewalem ◽  
K. Johansson
Keyword(s):  
Gibbs Sampling ◽  
Maternal Effects ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Genetic Effects ◽  
Egg Weight ◽  
Zygote Development ◽  
Reproduction Traits ◽  
Female Reproductive Traits ◽  
Weight Trait

AbstractFertility, generally considered as a trait of the two parents, is perhaps best defined as the interaction between the male and female gametes in the production of a viable zygote. Although zygote development and hatchability are traits of the embryo influenced by maternal effects, in most previous studies they have been considered to be female reproductive traits. The aim of this work was to study the influence of sire on fertility and hatchability traits and to estimate the (co)variance components of direct and maternal genetic effects under a Bayesian setting via Gibbs sampling. We measured the fertility of 6396 eggs and the hatchability of 5393 embryos on an individual basis. In addition, egg weight from 42 to 63 weeks of age (EW63) was recorded on an individual egg basis. The sire accounted for a significant amount of the variation infertility and hatchability. For direct heritability, the marginal posterior mean, for fertility and hatchability were almost equal (0·24). The maternal heritabilities for fertility and hatchability were 0·20 and 0·18, respectively. The direct heritability value for the egg weight trait was high. The direct-direct genetic correlation between egg weight and hatchability was negative and significant. The genetic correlations between the direct effect of the egg weight trait and maternal effects for fertility and hatchability were low, with variable signs, and were not significant. On the other hand, significant negative genetic correlations between direct and maternal effects of fertility and hatchability were obtained (the posterior means were –0·56 for FE and –0·55 for HC).

PSVII-29 Genetic analysis of frame score and performance traits in Nellore cattle – reproduction and productivity traits

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 238-238
Author(s):  
Fernando S Baldi ◽  
Maria Paula Negreiros ◽  
Elisa Peripolli ◽  
Claudio U Magnabosco ◽  
Nayanny Guimarães ◽  
...  
Keyword(s):  
Animal Model ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Genetic Correlations ◽  
Genetic Selection ◽  
Heritability Estimate ◽  
Reproductive Traits ◽  
Scrotal Circumference ◽  
Nellore Cattle ◽  
Cattle Reproduction

Abstract Frame score systems developed for Bos taurus breeds do not translate well for Bos indicus breeds, as these tend to be taller. We evaluated a novel frame score system for Nellore cattle raised on pasture [Guimaraes et al., 2020 J, Anim. Sci. 98 (Suppl. 4)]. Traits included adjusted scrotal circumference (cm) at 365 (SC365) and 450 (SC450) days of age, age at first calving (AFC, d), early heifer pregnancy (EHP, % calving as two-year-olds), stayability (STAY, % of cows remaining in the herd over 76 months of age, calving at least three times), and accumulated productivity (AP, kg of calf weaned per cow per year). In this study, we applied the previously developed equations (that also include hip height (HH, cm) and age to 12,049 records from the National Association of Breeders and Researchers (ANCP) database:FSmales= -20.35 + 0.1305*REA + 0.2633*BF - 0.5901*RF + 0.1139*HH + 0.0056*AGEFSfemales = -11.87 + 0.1316*REA - 0.2457*BF - 0.6218*RF + 0.1139*HH + 0.0009507*AGEThe (co)variance components and genetic parameters were estimated using a linear animal model or a threshold animal model depending on the trait. The heritability estimate for frame score was moderate (0.30). Estimated genetic correlations for reproductive traits were low to moderate (SC365, 0.06; SC450, 0.04; AFC, 0.18; EHP, -0.24; STAY, 0.06; AP, 0.25). The estimates support the notion that larger frame animals are later maturing but have greater lifetime productivity. The new frame score may be a useful tool for genetic selection of animals that are best suited to their environment.

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