two populations in same model

Dear all,

I am wanting to run a random regression model for two separate populations (with separate pedigrees, ie no geneflow between them) in order to get out a p-value for if the two populations differ significantly in their GxE. How would one go about to code such a model in ASREML?

Say for instance one is interested in milk yield (MY) in different feeding regimes(kilo grass, kiloST standardized on the interval -1,+1):
Then the following model (assuming repeated measures) would give an estimate of GxE compared to a model with last term as a 0 order Legendre polynomial:

MY ~ fixed !r leg(kiloST,1).ide(IND) leg(kiloST,1).IND

I guess one way would be to fit a bivariate model with MY1 and MY2 and fix the covariance between them (because no geneflow and thus connectedness in pedigree) and give separate fixed effects for each population if needed, but how does it work with the two separate pedigrees?

Any pointers to literature, example code etc on this topic would be very appreciated.

Many thanks in advance,
Arild

-------------------- m2f --------------------

Sent using Mail2Forum (http://www.mail2forum.com).

Read this topic online here:
http://www.vsni.co.uk/forum/viewtopic.php?p=256#256

-------------------- m2f --------------------
Received on Wed Oct 13 2008 - 11:40:19 EST