Genetic parameter estimates and principal component analysis of breeding values of reproduction and growth traits in female Canchim cattle

2013 ◽  
Vol 25 (5) ◽  
pp. 775 ◽  
Author(s):  
M. E. Buzanskas ◽  
R. P. Savegnago ◽  
D. A. Grossi ◽  
G. C. Venturini ◽  
S. A. Queiroz ◽  
...  

Phenotypic data from female Canchim beef cattle were used to obtain estimates of genetic parameters for reproduction and growth traits using a linear animal mixed model. In addition, relationships among animal estimated breeding values (EBVs) for these traits were explored using principal component analysis. The traits studied in female Canchim cattle were age at first calving (AFC), age at second calving (ASC), calving interval (CI), and bodyweight at 420 days of age (BW420). The heritability estimates for AFC, ASC, CI and BW420 were 0.03 ± 0.01, 0.07 ± 0.01, 0.06 ± 0.02, and 0.24 ± 0.02, respectively. The genetic correlations for AFC with ASC, AFC with CI, AFC with BW420, ASC with CI, ASC with BW420, and CI with BW420 were 0.87 ± 0.07, 0.23 ± 0.02, –0.15 ± 0.01, 0.67 ± 0.13, –0.07 ± 0.13, and 0.02 ± 0.14, respectively. Standardised EBVs for AFC, ASC and CI exhibited a high association with the first principal component, whereas the standardised EBV for BW420 was closely associated with the second principal component. The heritability estimates for AFC, ASC and CI suggest that these traits would respond slowly to selection. However, selection response could be enhanced by constructing selection indices based on the principal components.

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson

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.


2021 ◽  
Vol 38 (1) ◽  
pp. 14-22
Author(s):  
M. Orunmuyi ◽  
I. A. Adeyinka ◽  
O.O Oni

A study was conducted to estimate the genetic parameters of fertility and hatchability in two strains of Rhode Island Red (RIR) Chickens denoted as Strain A and Strain B respectively using the full-sib (sire +dam variance) and maternal half-sib (dam variance) components. The birds were obtained from the selected populations of RIR Chickens kept at the poultry breeding programme of National Animal Production Research Institute, Shika, Zaria, Nigeria. Settable eggs were collected from mating 28 cocks to 252 hens in a ratio of 1cock:9 hens from each strain. Eggs were pedigreed according to sire and dam. Results showed that values obtained for number of egg set (EGGSET), number of fertile eggs (NFERT), number of hatched chicks (NHATCH), percentage of chicks hatched from total eggs set (PHATCH) and percentage of chicks hatched from fertile eggs (PHATCHBL) were all higher in strain A than strain B. Heritability estimates obtained from the full-sib and maternal half-sib analysis ranged from medium to high for the two strains (0.24-0.96). The maternal half sib estimates were higher (0.40-0.96) than the estimates obtained from full sibs (0.24- 0.48). Genetic and phenotypic correlations obtained for both strains were positive and similar regardless of method of estimation. Genetic correlations between EGGSET and PFERT were low in strain A using both full-sib and maternal half-sib analyses (0.09-0.14). Phenotypic correlations between EGGSET and PFERT, PHATCH and PHATCHBL were also low in both strains and regardless of method of analyses. Moderate to high heritability estimates suggest that genetic improvement can be obtained by selection of these reproductive traits. The full-sib analysis for estimating heritability will be preferred since it is assumed that only additive genetic variance contributes to the covariance between family members.


2010 ◽  
Vol 93 (6) ◽  
pp. 2765-2774 ◽  
Author(s):  
N.P.P. Macciotta ◽  
G. Gaspa ◽  
R. Steri ◽  
E.L. Nicolazzi ◽  
C. Dimauro ◽  
...  

1994 ◽  
Vol 24 (7) ◽  
pp. 1480-1486 ◽  
Author(s):  
R.J. Arnold ◽  
J.B. Jett ◽  
S.E. McKeand

Open-pollinated progeny trials of Fraser fir (Abiesfraseri (Pursh) Poir.) assessed at 8 years provided genetic parameter estimates for growth, Christmas tree quality traits, and wholesale value at harvest age. Significant variation was found between and within nine different seed sources. Estimated individual tree heritabilities of important traits ranged from a low of 0.13 for USDA Christmas tree grade to a moderate value of 0.33 for crown diameter. Heritabilities within the better performing seed sources tended to be higher. Of the two traits that determine wholesale value, USDA grade and height class, the latter proved to have the greater influence, both phenotypically and genetically. Genetic correlations of early age height growth with 8-year total height, height class, USDA Christmas tree grade, and individual tree wholesale value proved favorable and strong (range of 0.57–0.96). In combination with moderate heritabilities for early growth traits, such correlations provide potential for effective early age selections in Fraser fir Christmas trees.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 21-22
Author(s):  
Lindsay R Upperman ◽  
Larry A Kuehn ◽  
Matthew L Spangler

Abstract The objective of this study was to estimate genetic parameters for days on feed (DOF), age at slaughter (AAS), and their relationships with carcass traits, including: marbling score (MARB), adjusted fat thickness (AFT), hot carcass weight (HCW), ribeye area (REA), and final live weight (FW). Data were from steers and heifers (n = 7,747) from the Germplasm Evaluation Program at the U.S. Meat Animal Research Center. All traits were analyzed with univariate and bivariate animal models using ASReml. Fixed effects fitted for all models included contemporary group (concatenation of birth year and season, sex, and experimental treatment group), breed fractions, and direct heterosis. Different endpoints were also investigated by fitting fixed linear covariates of AFT, HCW, REA, MARB, FW, and age (except AAS and DOF). For a given bivariate analyses, both traits were adjusted to the same endpoint. Univariate heritability estimates for AFT, AAS, DOF, FW, HCW, MARB, and REA ranged from 0.45–0.52, 0.52–0.59, 0.33–0.39, 0.34–0.55, 0.34–0.55, 0.54–0.55, and 0.50–0.56, respectively. Covariates of MARB and AFT led to the highest and lowest, respectively, heritability estimates for AAS and DOF. Depending on the endpoint, genetic correlations between AAS and AFT, FW, HCW, MARB, and REA ranged from 0.16 to 0.32, -0.08 to 0.33, 0.19 to 0.36, 0.14 to 0.20, and -0.06 to 0.13 (Table 1). Genetic correlations between DOF and AFT, MARB, and REA were negligible. Genetic correlations between DOF, FW, and HCW ranged from -0.10 to 0.29 and -0.37 to -0.17. Standard errors were less than 0.07 for all estimates. Phenotypic variability in DOF was low, and increased variability in AAS was due to differences in date of birth and thus weaning age. Results indicate DOF and AAS are moderately to highly heritable and generally lowly correlated with routine carcass traits. The USDA is an equal opportunity employer.


2005 ◽  
Vol 48 (3) ◽  
pp. 261-269 ◽  
Author(s):  
H. Atil ◽  
A. S. Khattab ◽  
L. Badawy

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.


2019 ◽  
Vol 40 (6Supl2) ◽  
pp. 3269
Author(s):  
Natália Albieri Koritiaki ◽  
Edson Luis de Azambuja Ribeiro ◽  
Carolina Amália Souza Dantas Muniz ◽  
Bruna Silva Marestone ◽  
Francisco Fernandes Junior

The aim of this study was to evaluate the interrelation among growth traits in Santa Inês lambs using principal component analysis. Data on 270 lambs born between 2008 and 2013 were used. The variables studied were weight at birth,adjusted weight from birth to weaning, and average daily gains at 14, 28, 52, and 70 days of age. The wither height, thoracic perimeter, and length at birth and adjusted at 28 and 70 days of age (weaning), were also used. The statistical model comprised the fixed effects of the contemporary group, the linear effect of julian date at birth, and the linear and quadratic effects of lambing weight. The first principal component explained approximately 89% and 85% of the total variation for body weight at different ages and average daily gains, respectively. The second principal component compared heavier animals or those that gained more weight at 14 days with lighter lambs or those that gained less weight at 14 days of age and explains the variation of approximately 5% and 10%, respectively, among the animals. The first principal component accounted for 77%, 91%, and 77% of the variation for weight, thoracic perimeter, wither height, and length at birth, 28 days, and 70 days of age, respectively, and compared large animals or animals with greater body volume. The second component, with values of 16%, 6%, and 14% of the total variation at the three ages, respectively, compared animals with distinct conformation to discriminate animals of different shapes and verified that the weights at the different ages and the thoracic perimeter are important sources of variability among the animals.


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