coding R structure in a bivariate model

Hello,

I am trying to fit a bivariate animal model where one trait (BW) has
repeated measures on 408 animals, (with phenotype recorded at 13 ages),
and the other trait (ELF) is measured only once. I've performed a
univariate analysis of BW (part 1 below) using a simple random
regression model (on age) for the additive effect, a pe effect, and a
diagonal error structure that has 13 age-specific residual variances.
The univariate analysis of ELF (part 2 below) is a straightforward
animal model partitioning variance into Va and Vr.

However, I'd like to run a bivariate model (part 3) and I'm having
trouble working out how to code the R structure. What I have below (part
3) works but fits a single Vr across all
age classes for BW. What I'd like to end up with the age specific Vr's
for BW (as in my univariate model), a Vr for ELF, and a COVr between BW
at each age and ELF, i.e. a structure like:

?
0 ?
0 0 ?
0 0 0 ?
0 0 0 0 ?
0 0 0 0 0 ?
0 0 0 0 0 0 ?
0 0 0 0 0 0 0 ?
0 0 0 0 0 0 0 0 ?
0 0 0 0 0 0 0 0 0 ?
0 0 0 0 0 0 0 0 0 0 ?
0 0 0 0 0 0 0 0 0 0 0 ?
0 0 0 0 0 0 0 0 0 0 0 0 ?
? ? ? ? ? ? ? ? ? ? ? ? ? ?

Where "?" is a (co)variance to be estimated
Below is the code I have so far, if anyone can offer any suggestions I'd
be very grateful.

Best,

Alastair

####################################
!part 1 # random regression model for BW

# 12 age-specific records for each of 408 animals
#ageF is age as 13 level factor

BW ~ mu age !r !{animal animal.age !} ide(animal)

1 2 2 !STEP 0.001

408
ageF 0 DIAG !S2==1
1 1 1 1 1 1 1 1 1 1 1 1 1 #13 starting values

animal 2
animal 0 US
1.277
0.1132 0.1287
animal

ide(animal) 1
ide(animal) 0 ID 0.1

###########################

!part 2 #univariate animal model for ELF

ELF ~ mu !r animal

##############################

!part 3 #bivariate model

BW ELF ~ Trait at(Tr,1).age !r !{Trait.animal at(Tr,1).animal.age
!} at(Tr,1).ide(animal)

1 2 2

0
Trait 0 US !S2==1
1
0 1

Trait.animal 2
3 0 US
0.3
0.1 1.2
0.1 0.1 0.13
animal 0 AINV

at(Tr,1).ide(animal) 1
ide(animal) 0 ID 0.1

--
Alastair J Wilson
NERC Research Fellow
Alastair.Wilson_at_ed.ac.uk
http://www.biology.ed.ac.uk/research/groups/awilson/
tel. 0131 6513673
Institute of Evolutionary Biology
School of Biological Sciences
The University of Edinburgh
Ashworth Laboratories
The King's Buildings
West Mains Road
Edinburgh EH9 3JT, UK