Bivariate binomial

I need some assistance to estimate the genetic correlations of two
binomial traits. The univariate analysis converged with expected
results.

The data file for the bivariate binomial analysis has been set up as
follows (one field defines the trait and another field has the binary
score of that trait):
Binrait score
1 1
1 0
1 0
...
2 1
2 1
2 0

The model I have is as follows:
ASREML Linear threshold model
# anim !P
 sire !P
 dam !P
 bintrait # trait 1 or 2
 binscore # binary score 0 or 1 with trait defined in field
bintrait
bi.ped # pedigree file
bi.dat !ASUV !MAXIT 100 # data file
binscore !BINOMIAL !PROBIT ~ Trait bintrait !r Trait.bintrait.sire
#ran but with singularity
#binsc !BINOMIAL !PROBIT ~ Trait !r Trait.bintrait.sire
#ran unable to invert R or G matrix
1 2 1
0 0 0
Trait 0 US 1 !GP
Trait.bintrait.sire 2
2 0 US !GP !+3
.06
.05 .06
 0 0 AINV

I was unsuccessful in getting convergence. Is the model above correct
to determine genetic correlations of binomial traits?
From what I have seen in the literature a sire model is preferred in
binomial analyses as the animal model does not behave well. Has anyone
had experiences with the stability of bivariate binomial estimates?

Regards
Michael Macbeth
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Received on Mon May 31 2007 - 12:54:13 EST