scholarly journals Estimation of Genetic Parameters and Trends for Additive Direct and Maternal Genetic Effects for Birth and Calf-market Weights in Japanese Black Beef Cattle

2000 ◽  
Vol 71 (5) ◽  
pp. 462-469 ◽  
Author(s):  
Fumio MUKAI ◽  
Akira YAMAGAMI ◽  
Katsuhito ANADA
Keyword(s):  
Beef Cattle ◽  
Genetic Parameters ◽  
Genetic Effects ◽  
Estimation Of Genetic Parameters ◽  
Market Weights

scholarly journals Use of robust multivariate linear mixed models for estimation of genetic parameters for carcass traits in beef cattle

2014 ◽  
Vol 131 (6) ◽  
pp. 504-512 ◽  
Author(s):  
S.O. Peters ◽  
K. Kizilkaya ◽  
D.J. Garrick ◽  
R.L. Fernando ◽  
E.J. Pollak ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Mixed Models ◽  
Genetic Parameters ◽  
Linear Mixed Models ◽  
Carcass Traits ◽  
Estimation Of Genetic Parameters

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

2014 ◽  
Vol 59 (No. 7) ◽  
pp. 302-309 ◽  
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.

scholarly journals Selection of a suitable data set and model for the estimation of genetic parameters of the weaning weight in beef cattle

2007 ◽  
Vol 50 (6) ◽  
pp. 562-574
Author(s):  
L. Vostrý ◽  
J. Přibyl ◽  
Z. Veselá ◽  
V. Jakubec
Keyword(s):  
Beef Cattle ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Genetic Effect ◽  
Suitable Model ◽  
Data Set ◽  
Weaning Weight ◽  
Estimation Of Genetic Parameters ◽  
Selection Of

Abstract. The objective of this paper was to select a suitable data subset and statistical model for the estimation of genetic parameters for weaning weight of beef cattle in the Czech Republic. Nine subsets were tested for the selection of a suitable subset. The subsets differed from each other in the limit of sampling criteria. The most suitable subset satisfied these conditions: at least 5 individuals per each sire, 5 individuals per HYS (herd, year, season), 2 sires per HYS, and individuals per dams that have at least one half-sister and two offspring (n = 4 806). The selection of a suitable model was carried out from 10 models. These models comprised some of the random effects: direct genetic effect, maternal genetic effect, permanent maternal environment effect, HYS, sire × herd or sire × year interaction, and some of the fixed effects: dam’s age, sex (young bull, heifer × single, twin born), HYS, year, herd. The direct heritability (h2a) ranged from 0.06 to 0.17, of maternal heritability (h2m) from 0.03 to 0.06. The genetic correlations between the direct and maternal effect (ram) were in the range of –0.15 –0.42.

GENETIC PARAMETERS OF THE MATERNAL GRANDSIRE CONTRIBUTION TO BEEF CATTLE WEANING WEIGHTS

1982 ◽  
Vol 62 (4) ◽  
pp. 1057-1062
Author(s):  
G. H. CROW ◽  
W. E. HOWELL
Keyword(s):  
Beef Cattle ◽  
Key Words ◽  
Variance Components ◽  
Genetic Parameters ◽  
Mixed Model ◽  
Genetic Effects ◽  
Performance Data ◽  
Maternal Influence ◽  
Weaning Weight ◽  
Maternal Grandsire

Genetic aspects of maternal influence on weaning weights in beef cattle were examined using analyses within breed and parity of dam (first, second, third and fourth and greater parities) of Angus, Charolais and Hereford Record of Performance data. A mixed model which included herd-year and maternal grandsire (MGS) was used. The data were adjusted for calf sex within breed and parity of dam prior to analysis. The heritability of dam influence on her offspring weaning weight averaged 0.23 for first parity data of the three breeds. Heritability for second and third parities of the three breeds were lower than this but averaged 0.16 in parity four and greater. MGSs contributed significantly to variation in weaning weights. Their contribution, however, is a composite of both direct and maternal genetic effects. Key words: Beef cattle, weaning weight, maternal, variance components, heritability

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