scholarly journals Analyses of growth curves of Nellore cattle by Bayesian method via Gibbs sampling

2003 ◽  
Vol 55 (4) ◽  
pp. 480-490 ◽  
Author(s):  
P.R.C. Nobre ◽  
P.S. Lopes ◽  
R.A. Torres ◽  
L.O.C. Silva ◽  
A.J. Regazzi ◽  
...  
Keyword(s):  
Birth Weight ◽  
Bayesian Method ◽  
Growth Curves ◽  
Random Regression ◽  
Multiple Trait ◽  
Covariance Functions ◽  
Contemporary Group ◽  
Random Regression Model ◽  
Nellore Cattle ◽  
Covariance Components

Growth curves of Nellore cattle were analyzed using body weights measured at ages ranging from 1 day (birth weight) to 733 days. Traits considered were birth weight, 10 to 110 days weight, 102 to 202 days weight, 193 to 293 days weight, 283 to 383 days weight, 376 to 476 days weight, 551 to 651 days weight, and 633 to 733 days weight. Two data samples were created: one with 79,849 records from herds that had missing traits and another with 74,601 from herds with no missing traits. Records preadjusted to a fixed age were analyzed by a multiple trait model (MTM), which included the effects of contemporary group, age of dam class, additive direct, additive maternal, and maternal permanent environment. Analyses were carried out by a Bayesian method for all nine traits. The random regression model (RRM) included the effects of age of animal, contemporary group, age of dam class, additive direct, permanent environment, additive maternal, and maternal permanent environment. Legendre cubic polynomials were used to describe random effects. MTM estimated covariance components and genetic parameters for birth weight and sequential weights and RRM for all ages. Due to the fact that covariance components based on RRM were inflated for herds with missing traits, MTM should be used and converted to covariance functions.

scholarly journals Genetic evaluation for large data sets by random regression models in Nellore cattle

2009 ◽  
Vol 61 (4) ◽  
pp. 959-967
Author(s):  
P.R.C. Nobre ◽  
A.N. Rosa ◽  
L.O.C. Silva
Keyword(s):  
Large Data ◽  
Genetic Evaluation ◽  
Large Data Sets ◽  
Random Regression ◽  
Data Sets ◽  
Multiple Trait ◽  
Contemporary Group ◽  
Random Regression Model ◽  
Nellore Cattle ◽  
Covariance Components

Expected progeny differences (EPD) of Nellore cattle estimated by random regression model (RRM) and multiple trait model (MTM) were compared. Genetic evaluation data included 3,819,895 records of up nine sequential weights of 963,227 animals measured at ages ranging from one day (birth weight) to 733 days. Traits considered were weights at birth, ten to 110-day old, 102 to 202-day old, 193 to 293-day old, 283 to 383-day old, 376 to 476-day old, 551 to 651-day old, and 633 to 733-day old. Seven data samples were created. Because the parameters estimates biologically were better, two of them were chosen: one with 84,426 records and another with 72,040. Records preadjusted to a fixed age were analyzed by a MTM, which included the effects of contemporary group, age of dam class, additive direct, additive maternal, and maternal permanent environment. Analyses were carried out by REML, with five traits at a time. The RRM included the effects of age of animal, contemporary group, age of dam class, additive direct, permanent environment, additive maternal, and maternal permanent environment. Different degree of Legendre polynomials were used to describe random effects. MTM estimated covariance components and genetic parameters for weight at birth and sequential weights and RRM for all ages. Due to the fact that correlation among the estimates EPD from MTM and all the tested RM were not equal to 1.0, it is not possible to recommend RRM to genetic evaluation to large data sets.

Analyses of growth curves of Nellore cattle by multiple-trait and random regression models

2003 ◽  
Vol 81 (4) ◽  
pp. 918-926 ◽  
Author(s):  
P. R. C. Nobre ◽  
I. Misztal ◽  
S. Tsuruta ◽  
J. K. Bertrand ◽  
L. O. C. Silva ◽  
...  
Keyword(s):  
Regression Models ◽  
Growth Curves ◽  
Random Regression ◽  
Multiple Trait ◽  
Nellore Cattle

scholarly journals Genetic parameters for post weaning growth of Nellore cattle using polinomyals and trigonometric functions in random regression models

2009 ◽  
Vol 66 (4) ◽  
pp. 522-528 ◽  
Author(s):  
Osmar Jesus Macedo ◽  
Décio Barbin ◽  
Gerson Barreto Mourão
Keyword(s):  
Regression Models ◽  
Growth Curves ◽  
Information Criterion ◽  
The Other ◽  
Random Regression ◽  
Trigonometric Functions ◽  
Coefficient Estimates ◽  
Covariance Functions ◽  
Nellore Cattle ◽  
Selection Of

Covariance functions and random regression models have been considered as an alternative for data adjustment, in sequence, stemming from the same animal along time and which presents a structured pattern of covariance. Aiming to evaluate the performance of random regression models based on the Legendre, modified Jacobi and trigonometric functions, data concerning the weights of Nellore breed animals were used from birth to the 800th day of life, in models that assumed direct additive and animal permanent environmental effects coefficients. The Schwarz Bayesian information criterion (BIC) led to the selection of the models Legendre of order six (ML6), Jacobi of order five (MJ5) and trigonometric of order six (MT6), the ML6 model presenting the lowest BIC. At the extremity of the interval, the MJ5 model presented lower variance of component estimates than those obtained through the ML6 model, however the estimates were in accordance to the medium part of the interval; while the estimates from the MT6 model were oscillating and different from those obtained through the other models. At the extremity of the interval, the heritability coefficient estimates (<img src="/img/revistas/sa/v66n4/h4_circ.gif" align="absmiddle">2) obtained through the MJ5 model were lower than those obtained through the ML6 model, however, in the medium part of the interval, they were in accordance, remaining between 0.2 and 0.3. The values obtained through the MT6 model were different from those obtained through the other models, remaining between 0.35 and 0.40 on the first 285th days and then dropping to 0.01 on the 800th days of life. The means of the estimated growth curves started to distance from the data mean tendency from the 470th days on, and in this interval, the MT6 model was the most suitable.

scholarly journals Genetic parameters for test-day model with random regressions for production traits of Czech Holstein cattle

2011 ◽  
Vol 50 (No. 4) ◽  
pp. 142-154 ◽  
Author(s):  
L. Zavadilová ◽  
J. Jamrozik ◽  
Schaeffer LR
Keyword(s):  
Milk Fat ◽  
Sampling Method ◽  
Random Regression ◽  
Model Parameters ◽  
Residual Variance ◽  
Posterior Distributions ◽  
Production Traits ◽  
Multiple Trait ◽  
Holstein Breed ◽  
Random Regression Model

Multiple-lactation random regression model was applied to test-day records of milk, fat and protein yields in the first three lactations of the Czech Holstein breed. Data included 9&nbsp;583 cows, 89&nbsp;584, 44&nbsp;207 and 11&nbsp;266 test-day records in the first, second and third lactation, respectively. Milk, fat and protein in the first three lactations were analysed separately and in a multiple-trait analysis. Linear model included herd-test date, fixed regressions within age-season class and two random effects: animal genetic and permanent environment modelled by regressions. Gibbs sampling method was used to generate samples from marginal posterior distributions of the model parameters. The single- and multiple-trait models provided similar results. Genetic and permanent environmental variances and heritability for particular days in milk were high at the beginning and at the end of lactation. The residual variance decreased throughout the lactation. The resulting heritability ranged from 0.13 to 0.52 and increased with parity. &nbsp;

scholarly journals Genetic evaluation of growth traits in Nellore cattle through multi-trait and random regression models

2018 ◽  
Vol 63 (No. 6) ◽  
pp. 212-221 ◽  
Author(s):  
B.B. Teixeira ◽  
R.R. Mota ◽  
R.B. Lôbo ◽  
L.P. Silva ◽  
A.P. Souza Carneiro ◽  
...  
Keyword(s):  
Random Effects ◽  
Variance Components ◽  
Regression Models ◽  
Growth Traits ◽  
Growth Curves ◽  
Genetic Evaluation ◽  
Information Criteria ◽  
Random Regression ◽  
Nellore Cattle ◽  
Heritability Estimates

We aimed to evaluate different orders of fixed and random effects in random regression models (RRM) based on Legendre orthogonal polynomials as well as to verify the feasibility of these models to describe growth curves in Nellore cattle. The proposed RRM were also compared to multi-trait models (MTM). Variance components and genetic parameters estimates were performed via REML for all models. Twelve RRM were compared through Akaike (AIC) and Bayesian (BIC) information criteria. The model of order three for the fixed curve and four for all random effects (direct genetic, maternal genetic, permanent environment, and maternal permanent environment) fits best. Estimates of direct genetic, maternal genetic, maternal permanent environment, permanent environment, phenotypic and residual variances were similar between MTM and RRM. Heritability estimates were higher via RRM. We presented perspectives for the use of RRM for genetic evaluation of growth traits in Brazilian Nellore cattle. In general, moderate heritability estimates were obtained for the majority of studied traits when using RRM. Additionally, the precision of these estimates was higher when using RRM instead of MTM. However, concerns about the variance components estimates in advanced ages via Legendre polynomial must be taken into account in future studies.

scholarly journals Analysis of longitudinal data of Nellore cattle from performance test at pasture using random regression model

SpringerPlus ◽  
2012 ◽  
Vol 1 (1) ◽  
Author(s):  
Fernando Brito Lopes ◽  
Cláudio Ulhôa Magnabosco ◽  
Fernanda Paulini ◽  
Marcelo Corrêa da Silva ◽  
Eliane Sayuri Miyagi ◽  
...  
Keyword(s):  
Longitudinal Data ◽  
Regression Model ◽  
Performance Test ◽  
Random Regression ◽  
Random Regression Model ◽  
Nellore Cattle

Genetic evaluation of growth in Nellore cattle by multiple-trait and random regression models

2003 ◽  
Vol 81 (4) ◽  
pp. 927-932 ◽  
Author(s):  
P. R. C. Nobre ◽  
I. Misztal ◽  
S. Tsuruta ◽  
J. K. Bertrand ◽  
L. O. C. Silva ◽  
...  
Keyword(s):  
Regression Models ◽  
Genetic Evaluation ◽  
Random Regression ◽  
Multiple Trait ◽  
Nellore Cattle

scholarly journals Weight evaluation of Tabapuã cattle raised in northeastern Brazil using random-regression models

2017 ◽  
Vol 69 (2) ◽  
pp. 457-464 ◽  
Author(s):  
M.R. Oliveira ◽  
D.M. Azevêdo ◽  
C. Malhado ◽  
L. Pires ◽  
R. Martins Filho ◽  
...  
Keyword(s):  
Birth Weight ◽  
Regression Model ◽  
Growth Curve ◽  
Regression Models ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Northeastern Brazil ◽  
Random Regression ◽  
Phenotypic Correlation ◽  
Random Regression Model

ABSTRACT The objective of this study is to compare random-regression models used to describe changes in evaluation parameters for growth in Tabapuã bovine raised in the Northeast of Brazilian. The M4532-5 random-regression model was found to be best for estimating the variation and heritability of growth characteristics in the animals evaluated. Estimates of direct additive genetic variance increased with age, while the maternal additive genetic variance demonstrated growth from birth to up to nearly 420 days of age. The genetic correlations between the first four characteristics were positive with moderate to large ranges. The greatest genetic correlation was observed between birth weight and at 240 days of age (0.82). The phenotypic correlation between birth weight and other characteristics was low. The M4532-5 random-regression model with 39 parameters was found to be best for describing the growth curve of the animals evaluated providing improved selection for heavier animals when performed after weaning. The interpretation of genetic parameters to predict the growth curve of cattle may allow the selection of animals to accelerate slaughter procedures.

scholarly journals Covariance function of Legendre polynomials for the modeling of Polled Nellore cattle growth in northern Brazil

2019 ◽  
Vol 40 (2) ◽  
pp. 781
Author(s):  
Diego Helcias Cavalcante ◽  
Severino Cavalcante Sousa Júnior ◽  
Luciano Pinheiro Silva ◽  
Carlos Henrique Mendes Malhado ◽  
Raimundo Martins Filho ◽  
...  
Keyword(s):  
Fixed Effects ◽  
Growth Parameters ◽  
Random Effect ◽  
Growth Curves ◽  
Random Regression ◽  
Analytical Models ◽  
Residual Variance ◽  
Age Related ◽  
Nellore Cattle ◽  
Northern Brazil

This study aimed to compare random regression models fitted by Legendre orthogonal polynomials and determine which best fits changes in Nellore cattle growth parameters. Age polynomial functions of different orders were evaluated using a random-effect modeling associated with a genetic study of cattle growth curves. For this purpose, weight records (15,148) were performed in Polled Nellore bovines (3,115), aged between 1 and 660 days, reared in northern Brazil and born between 1995 and 2010. The fixed effects of analytical models comprised age-matched groups, heifer calving age (linear and quadratic), and fourth-order Legendre age polynomial (cubic), depicting the mean growth curve. Besides, different order functions were considered for random effects, so that (co) variance associated with genetic effects (direct and maternal) and permanent environmental effects (animal and maternal) could be modeled. Residual variance was fitted by six heterogeneous classes throughout the analyzed period. According to AIC and BIC criteria, the model 6333 allowed the fitting of changes in variance and covariance over time (genetic and environmental). Thus, this model can be used to describe age-related changes in Polled Nellore cattle reared in northern Brazil.

Sign in / Sign up

Export Citation Format

Share Document