Estimates of direct and maternal genetic parameters for weight traits and backfat thickness in a multibreed population of beef cattle

Variance components were estimated for weight at birth, weaning, and 365 d of age, and yearling ultrasonic backfat thickness in a multibreed population of beef cattle. Data (n = 5880) were available on F1 animals and various crosses leading up to, and including, a composite breed (7/16 British, 1/4 Charolais, 1/4 Simmental, and 1/16 Limousin). Single- and two-trait analyses were conducted using an animal model and derivative-free REML procedures. Covariates representing fractional contributions of each of the four purebred groups and average heterotic effects, both direct and maternal, accounted for breed composition. Direct and maternal genetic, maternal permanent environmental, and residual effects were the random variables. Only minor differences existed between parameter estimates obtained from the various analyses. Mean direct heritabilities were 0.51, 0.33, 0.48, and 0.37 for weight at birth, weaning, and 365-d, and backfat, respectively, which, though well within the range of published estimates, seemed higher than average, indicating diversity in the founding purebreds. Mean maternal heritabilites were 0.09, 0.13, and 0.08 for the three consecutive weights. A likelihood ratio test showed maternal heritability and(or) the direct-maternal correlation was important (P < 0.001) for 365-d weight. Averaged across weights, the direct-maternal correlation was 0.07, lacking evidence of genetic antagonism. No age of dam or random maternal effects on backfat were apparent. Phenotypic correlations between weight at birth and weaning and weight at weaning and 365-d were 0.46 and 0.76, respectively. Though moderate between birth and weaning weight, maternal genetic and permanent environmental correlations between weaning and 365-d weight approached unity, demonstrating maternal carryover effects. Phenotypic and genetic correlations of 0.19 and –0.13, respectively, implied a limited association between 365-d weight and backfat, which possibly would have been stronger had fat been measured later in life. Estimates of variance components suitable for general use can be obtained from data from multibreed animals by considering breed and heterotic effects. Key words: Beef cattle, crossbreds, genetic parameters, heritability, maternal effects

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Genetic parameters for test day milk yield of first lactation Holstein cows estimated by random regression using Legendre polynomials

Revista Brasileira de Zootecnia ◽

10.1590/s1516-35982008000400003 ◽

2008 ◽

Vol 37 (4) ◽

pp. 602-608 ◽

Cited By ~ 26

Author(s):

Claudio Napolis Costa ◽

Claudio Manoel Rodrigues de Melo ◽

Irineu Umberto Packer ◽

Ary Ferreira de Freitas ◽

Nilson Milagres Teixeira ◽

...

Keyword(s):

Variance Components ◽

Legendre Polynomials ◽

Genetic Parameters ◽

Genetic Correlations ◽

Random Regression ◽

Holstein Cows ◽

Residual Variance ◽

Environmental Variance ◽

Environmental Correlations ◽

Lp Estimates

Data comprising 263,390 test-day (TD) records of 32,448 first parity cows calving in 467 herds between 1991 and 2001 from the Brazilian Holstein Association were used to estimate genetic and permanent environmental variance components in a random regression animal model using Legendre polynomials (LP) of order three to five by REML. Residual variance was assumed to be constant in all or in some classes of lactation periods for each LP. Estimates of genetic and permanent environmental variances did not show any trend due to the increase in the LP order. Residual variance decreased as the order of LP increased when it was assumed constant, and it was highest at the beginning of lactation and relatively constant in mid lactation when assumed to vary between classes. The range for the estimates of heritability (0.27 - 0.42) was similar for all models and was higher in mid lactation. There were only slight differences between the models in both genetic and permanent environmental correlations. Genetic correlations decreased for near unity between adjacent days to values as low as 0.24 between early and late lactation. A five parameter LP to model both genetic and permanent environmental effects and assuming a homogeneous residual variance would be a parsimonious option to fit TD yields of Holstein cows in Brazil.

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Estimates of (co)variance components and genetic parameters for growth traits in Suffolk lambs

Ciência Rural ◽

10.1590/s0103-84782013001200016 ◽

2013 ◽

Vol 43 (12) ◽

pp. 2215-2220 ◽

Cited By ~ 6

Author(s):

Priscilla Regina Tamioso ◽

Jaime Luiz Alberti Filho ◽

Laila Talarico Dias ◽

Rodrigo de Almeida Teixeira

Keyword(s):

Maternal Effects ◽

Variance Components ◽

Genetic Parameters ◽

Growth Traits ◽

Genetic Effect ◽

Additive Genetic Effect ◽

Ratio Test ◽

Effect Model ◽

Estimate Heritability ◽

Heritability Estimates

The study aimed to estimate the components of (co)variance and heritability for weights at birth (BW), weaning (WW) and 180 days of age (W180), as well as the average daily gains from birth to weaning (ADG1), birth to 180 days of age (ADG2) and weaning to 180 days of age (ADG3) in Suffolk sheep. Thus, three different single-trait animal models were fitted, considering the direct additive genetic effect (Model 1), the direct additive genetic and maternal permanent environmental effects (Model 2), and in Model 3, in addition to those in Model 2, the maternal additive genetic effect was included. After comparing models through the likelihood ratio test (LRT), model 3 was chosen as the most appropriate to estimate heritability for BW, WW and ADG1. Model 2 was considered as the best to estimate the coefficient of heritability for W180 and ADG2, and model 1 for ADG3. Direct heritability estimates were inflated when maternal effects were ignored. According to the most suitable models, the heritability estimates for BW, WW, W180, ADG1, ADG2 and ADG3 were 0.06, 0.08, 0.09, 0.07, 0.08 and 0.07, respectively, indicating low possibility of genetic gain through individual selection. The results show the importance of including maternal effects in the models to properly estimate genetic parameters even at post-weaning ages.

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Genetic parameters for liveweights of beef cattle in the tropics

Australian Journal of Agricultural Research ◽

10.1071/ar9921297 ◽

1992 ◽

Vol 43 (6) ◽

pp. 1297 ◽

Cited By ~ 6

Author(s):

DL Robinson ◽

PK O'Rourke

Keyword(s):

Genetic Analysis ◽

Beef Cattle ◽

Maternal Effects ◽

Genetic Parameters ◽

Genetic Correlations ◽

Statistical Analyses ◽

Phenotypic Variance ◽

The Tropics

This paper describes a genetic analysis of 20000 weighings from 1980-1988 on the progeny of more than 210 sires from three straightbred Brahman and one crossbred herd (Brahman or SahiwalxBritish breeds) in the Australian tropics. 200 day weight averaged 192 kg, very slightly less than 200 day weight in temperate Australia with similar phenotypic variance of 520 kg2. Mean 550, 700, and 900 day weights of 310, 350 and 450 kg and phenotypic variances of 800, 800 and 1485 kg2 were lower than in temperate regions at the same ages. Direct heritabilities for weight averaged 41% in the Brahmans and 31% in the crossbred herd. Genetic correlations amongst 200 day and later weights were 81-92%, except for an estimate of 63% between 200 and 900 day weights. Estimates of heritabilities for maternal effects were quite high in the crossbred herd for 200 and 365 day weights (19 and 14%), but only 4-5% for Brahmans. Models and statistical analyses are discussed and results compared with other published estimates from subtropical and temperate regions.

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Genetic parameters of growth of Ethiopian Boran cattle

Animal Science ◽

10.1017/s0003356100018559 ◽

1987 ◽

Vol 44 (2) ◽

pp. 201-208 ◽

Cited By ~ 4

Author(s):

Th. Arnason ◽

H. Kassa-Mersha

Keyword(s):

Birth Weight ◽

Maternal Effects ◽

Variance Components ◽

Genetic Parameters ◽

Genetic Correlations ◽

Genetic Covariance ◽

Weaning Weight ◽

Genetic Components ◽

Selection Indices ◽

The Individual

ABSTRACTRecords on birth weight and pre-weaning growth of 3959 Boran calves, which were progeny of 51 sires and 979 dams, were analysed by least-squares analysis of variance. The variance components for sires, dams and maternal grandsires were estimated from the data. On the basis of assumed genetic correlations −0·44 and −0·55 between direct and maternal effects on birth weight and weaning weight, respectively, the maternal genetic component and the genetic covariance between direct and maternal effects were estimated. The heritabilities for direct effects on birth weight and weaning weight were 0·11 and 0·22, respectively, while the heritabilities of maternal effects were estimated as 0·02 and 0·11, respectively for the same traits. Selection indices for direct and maternal genetic components of weaning weight were constructed for practical use. These selection indices combined information on the individual, the parents and sibs.

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Evaluation of Bonsmara and Belmont Red cattle breeds in South Africa. 2. Genetic parameters for growth and fertility

Australian Journal of Experimental Agriculture ◽

10.1071/ea05224 ◽

2006 ◽

Vol 46 (2) ◽

pp. 213 ◽

Cited By ~ 4

Author(s):

N. J. Corbet ◽

R. K. Shepherd ◽

H. M. Burrow ◽

K. C. Prayaga ◽

J. van der Westhuizen ◽

...

Keyword(s):

South Africa ◽

Maternal Effects ◽

Genetic Parameters ◽

Growth Traits ◽

Genetic Parameter ◽

Genetic Correlations ◽

Repeated Measurements ◽

Maternal Influence ◽

Parameter Estimates ◽

Fertility Traits

Genetic parameters were estimated for growth and fertility indicator traits in a South African beef cattle population. Measurements on 5601 pedigreed progeny of 96 Bonsmara sires, 18 Belmont Red sires and 20 Bonsmara × Belmont Red cross sires were recorded over 19 years in 4 diverse climatic regions of South Africa. Growth traits were measured on growing stock from birth to 18 months at pasture. Cow weights were measured at calving and weaning. Age at first calving, and repeated measurements of calving day and calving interval were recorded on 1993 breeding females as indicators of reproductive performance. The traits were analysed using univariate and bivariate animal models with maternal effects fitted. Direct heritability of growth traits (0.11–0.42) and female fertility traits (0.02–0.13) suggested that genetic progress could be made by selection for some traits. Genetic correlations between growth and fertility traits were variable (–0.47–0.85) and indicated that multi-trait selection would be the best method of dealing with multidirectional forces on productivity traits. Genetic correlations between direct and maternal effects on liveweight traits were mostly negative indicating that genetic improvement of traits with strong maternal influence, such as weaning weight, would be complicated and supported the use of post-weaning weights with less maternal influence as selection criteria to improve the direct additive component of growth. The genetic parameter estimates provide useful reference values for estimation of breeding values in a proposed combined-breed genetic evaluation program.

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Evaluating animal models comprising direct and maternal effects associated with growth rates and the Kleiber ratio in Harnali sheep

Zygote ◽

10.1017/s0967199421000605 ◽

2021 ◽

pp. 1-5

Author(s):

Ashish Chauhan ◽

S.P. Dahiya ◽

Ankit Magotra ◽

Yogesh C. Bangar

Keyword(s):

Animal Models ◽

Maternal Effects ◽

Growth Rates ◽

Variance Components ◽

Average Daily Gain ◽

Genetic Correlations ◽

Ratio Test ◽

Kleiber Ratio ◽

Managerial Strategies ◽

Daily Gain

Summary The present work evaluated animal models comprising direct and maternal effects to estimate (co)variance components and genetic parameters of growth rates and Kleiber ratio in Harnali sheep. The information on pedigree and targeted traits of 1862 lambs born to 144 sires and 591 dams was collected for the period from 1998 to 2018. The traits studied were average daily gain from birth to 3 months of age (ADG1), 3 months to 6 months of age (ADG2), and 6 months to 12 months of age (ADG3) and their corresponding Kleiber ratios as KR1, KR2 and KR3, respectively. The statistical methods included the general linear model for analyzing the effects of fixed factors and animal models for deriving variance components for targeted traits. According to best model evaluated on the basis of likelihood ratio test, the estimated direct heritability was low in magnitude and ranged from 0.04 to 0.14. Direct heritability estimates for ADG1, ADG2, ADG3, KR1, KR2 and KR3 were 0.06, 0.14, 0.05, 0.04, 0.11 and 0.05, respectively. The maternal genetic effects contributed (4–7%) significantly for ADG1, KR1 and KR2 traits. The genetic correlations ranged from −0.35 ± 0.11 (ADG1-KR2) to 0.98 ± 0.01 (ADG2-KR2 and ADG3-KR3) and phenotypic correlations ranged from −0.36 ± 0.02 to 0.98 ± 0.01 for ADG1-KR2 and ADG2-KR2, respectively. The significant maternal effects along with low levels of direct effects for average daily gain and Kleiber ratio at different age group should be considered while setting selection and managerial strategies to achieve anticipated growth rates in Harnali sheep.

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

Genetics ◽

10.1093/genetics/143.3.1409 ◽

1996 ◽

Vol 143 (3) ◽

pp. 1409-1416 ◽

Cited By ~ 1

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.

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Estimation of variance components of milk, fat, and protein yields of Tunisian Holstein dairy cattle using Bayesian and REML methods

Archives Animal Breeding ◽

10.5194/aab-59-243-2016 ◽

2016 ◽

Vol 59 (2) ◽

pp. 243-248 ◽

Cited By ~ 3

Author(s):

Hafedh Ben Zaabza ◽

Abderrahmen Ben Gara ◽

Hedi Hammami ◽

Mohamed Amine Ferchichi ◽

Boulbaba Rekik

Keyword(s):

Dairy Cattle ◽

Bayesian Methods ◽

Milk Fat ◽

Variance Components ◽

Genetic Parameters ◽

Genetic Correlations ◽

Bayesian Procedure ◽

Milk Traits ◽

Residual Variances ◽

Estimation Of Variance

Abstract. A multi-trait repeatability animal model under restricted maximum likelihood (REML) and Bayesian methods was used to estimate genetic parameters of milk, fat, and protein yields in Tunisian Holstein cows. The estimates of heritability for milk, fat, and protein yields from the REML procedure were 0.21 ± 0.05, 0.159 ± 0.04, and 0.158 ± 0.04, respectively. The corresponding results from the Bayesian procedure were 0.273 ± 0.02, 0.198 ± 0.01, and 0.187 ± 0.01. Heritability estimates tended to be larger via the Bayesian than those obtained by the REML method. Genetic and permanent environmental variances estimated by REML were smaller than those obtained by the Bayesian analysis. Inversely, REML estimates of the residual variances were larger than Bayesian estimates. Genetic and permanent correlation estimates were on the other hand comparable by both REML and Bayesian methods with permanent environmental being larger than genetic correlations. Results from this study confirm previous reports on genetic parameters for milk traits in Tunisian Holsteins and suggest that a multi-trait approach can be an alternative for implementing a routine genetic evaluation of the Tunisian dairy cattle population.

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(Co)variance components and genetic parameters for growth rate and Kleiber ratio in fat-tailed Mehraban sheep

Archives Animal Breeding ◽

10.7482/0003-9438-56-055 ◽

2013 ◽

Vol 56 (1) ◽

pp. 564-572 ◽

Cited By ~ 1

Author(s):

F. Ghafouri-Kesbi

Keyword(s):

Growth Rate ◽

Variance Components ◽

Genetic Parameters ◽

Average Daily Gain ◽

Genetic Correlations ◽

Phenotypic Variance ◽

Genetic Progress ◽

Kleiber Ratio ◽

Derivative Free ◽

Maternal Heritability

Abstract. The aim of the present study was to estimate (co)variance components and genetic parameters for average daily gain from birth to weaning (ADGa), weaning to 6 months (ADGb), weaning to 9 months (ADGc), 6 months to 9 months (ADGd) and corresponding Kleiber ratios (KRa, KRb, KRc and KRd) in Mehraban sheep. A derivative-free algorithm combined with a series of six univariate linear animal models was used to estimate phenotypic variance and its direct, maternal and residual components. In addition, bivariate analyses were done to estimate (co)variance components between traits. Estimates of direct heritability (h2) were 0.10, 0.11, 0.16, 0.09, 0.13, 0.13, 0.15 and 0.08 for ADGa, ADGb, ADGc, ADGd, KRa, KRb, KRc and KRd, respectively and indicate that in Mehraban sheep genes contribute very little to the variance of the growth rate and Kleiber ratio. Estimates of maternal heritability (m2) were 0.10, 0.08 and 0.05 for ADGa, KRa and KRb, respectively. Direct additive genetic correlations ranged from −0.32 (KRa-KRd) to 0.99 (ADGb-KRb) and phenotypic correlations ranged from −0.53 (ADGa- ADGd) to 0.99 (ADGa-KRa). Estimates of direct heritability and genetic correlations show that genetic improvement in efficiency of feed utilization through selection programmes is possible, though it would generate a relatively slow genetic progress.

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Comparison of models for estimating genetic parameters and predicting breeding values for birth weight and calving ease in Czech Charolais cattle

Czech Journal of Animal Science ◽

10.17221/7529-cjas ◽

2014 ◽

Vol 59 (No. 7) ◽

pp. 302-309 ◽

Cited By ~ 2

Author(s):

L. Vostrý ◽

Z. Veselá ◽

A. Svitáková ◽

H. Vostrá Vydrová

Keyword(s):

Animal Model ◽

Birth Weight ◽

Beef Cattle ◽

Fixed Effects ◽

Genetic Parameters ◽

Genetic Correlations ◽

Genetic Effects ◽

Parameters Estimation ◽

Calving Ease ◽

Heritability Estimates

The most appropriate model for genetic parameters estimation for calving ease and birth weight in beef cattle was selected. A total of 27 402 field records were available from the Czech Charolais breed. For estimation of genetic parameters for calving ease and body weight, three bivariate models were tested: a linear-linear animal model (L-LM) with calving ease classified into four categories (1 – easy; 2–4 – most difficult), a linear-linear animal model (SC-LM) in which calving ease scores were transformed into Snell scores (Snell 1964) and expressed as percentage of assisted calving (ranging 0–100%), and a bivariate threshold-linear animal model (T-LM) with calving ease classified into four categories (1 – easy, 2–4 – most difficult). All tested models included fixed effects for contemporary group (herd × year × season), age of dam, sex and breed of a calf. Random effects included direct and maternal genetic effects, maternal permanent environmental effect, and residual error. Direct heritability estimates for calving ease and birth weight were, with the use of L-LM, SC-LM, and T-LM, from 0.096 ± 0.013 to 0.226 ± 0.024 and from 0.210 ± 0.024 to 0.225 ± 0.026, respectively. Maternal heritability estimates for calving ease and birth weight were, with the use of L-LM, SC-LM, and T-LM, from 0.060 ± 0.031 to 0.104 ± 0.125 and from 0.074 ± 0.041 to 0.075 ± 0.040, respectively. Genetic correlations of direct calving ease with direct birth weight ranged from 0.46 ± 0.06 to 0.50 ± 0.06 for all tested models; whereas maternal genetic correlations between these two traits ranged from 0.24 ± 0.17 to 0.25 ± 0.53. Correlations between direct and maternal genetic effects within-trait were negative and substantial for all tested models (ranging from –0.574 ± 0.125 to –0.680 ± 0.141 for calving ease and from –0.553 ± 0.122 to –0.558 ± 0.118 for birth weight, respectively), illustrating the importance of including this parameter in calving ease evaluations. Results indicate that any of the tested models could be used to reliably estimate genetic parameters for calving ease for beef cattle in the Czech Republic. However, because of advantages in computation time and practical considerations, genetic analysis using SC-LM (transformed data) is recommended.

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