WOMBAT – A program for Mixed Model Analyses by Restricted Maximum Likelihood

# Example 15

This example illustrates how to pool estimates of covariance components by (penalized) maximum likelihood using WOMBAT.

The example is comprised of 14 traits, with 6 traits measured on few animals and the remaining records representing 4 traits with measures on males and females treated as different traits (Results from Meyer 2007; J. Anim. Breed. Genet, 124:50-64). There are results from 76 bivariate and one six-variate analysis to be combined. Due to traits measured on different subsets of animals (sexes) there are a number of residual covariances which are to be fixed at zero.

A: All part analyses have been carried out using WOMBAT and a full' parameter file is available

B: Results from part analyses are summarized in a single file and a minimum' parameter file is used.

Additional documentation for pooling is available in a set of notes which summarises the relevant options and directives available in WOMBAT, and shows a small, 4-trait example:

<bibtex> @Article{km12,

author =	 {Meyer, K.},
title =	 {A penalized likelihood approach to pooling estimates
of covariance components from analyses by parts},
journal =	 {Journal of Animal Breeding and Genetics},
year =	 2013,
volume =	 130,
number =	 4,
url =		 {http://dx.doi.org/10.1111/jbg.12004},
doi =		 {10.1111/jbg.12004},
pages =	 {270--285}

} </bibtex>