Re: Maternal effects in Random Regression

From: <arthur.gilmour_at_DPI.NSW.GOV.AU>
Date: Tue, 16 Sep 2008 11:32:22 +1000

Dear Seyed,

First, can I encourage you to use the ASReml forum at

I want to analyze a RR for a trait(body weight) with 16 repeated
measurements by ASReml. Is it possible to consider the maternal effects
only for the first 3 measurements? Or how I can omit maternal effects for
the last 13 measurements?

Thank you for any suggestion

Now a random regression is just modelling a set of contrasts based on the
16 times.

So, pol(age,2) sets up the 3 'contrast' vectors (reported in the .res

You are free to define contrasts however you liked

So one way to achieve your purpose would be to define new variables

 DageI != age !<30 # Create 0/1 variable 1 if age < 30
 DageS !=age !*DageI # has age if age < 30

Then in model !r !{ pol(age,2).animal DageI.dam DageS.dam

 pol(age,2).animal 2
5 0 US !GP
0.001 .1
2*0.001 .1
3*0.001 .1
4*0.001 .1
animal 0 AINV

assuming that 30 is a cutoff value that separates the first 3 from later
and that animal and dam are both !P pedigree terms.

You will need to adapt this depending on details you have not supplied but
I hope you get the idea.

May Jesus Christ continue to be gracious to you,

Arthur Gilmour, His servant .
Mixed model regression mapping for QTL detection in experimental crosses.
Computational Statistics and Data Analysis 51:3749-3764 at

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Skype: arthur.gilmour,
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Received on Thu Sep 16 2008 - 11:32:22 EST

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