Table of Contents
Paul VanRaden's deregressed proof
Yutaka Masuda
Overview
Quick answer
You need the output of accf90
which is a program available under an agreement with UGA.
A small script can compute VanRaden's (2009) deregressed proof based on PA, EBV, reliability of PA, and reliability of EBV.
Procedure
First, run blupf90
or other IOD programs to save solutions
.
Then, run accf90
with the following option in the parameter file.
It additionally calculates PA and its reliability.
OPTION parent_avg yes
The resulting sol_and_acc
file has 10 columns.
- Trait code
- Effect code
- Level code
- EBV
- Accuracy or reliability of EBV
- Parent average (PA)
- Unknown parent flag (1=both known; 2=sire unknown; 3=dam unknown; 4=both unknown)
- Sire code
- Dam code
- Accuracy or reliability of PA
VanRaden et al. (2009) showed a deregressed proof of sire can be available from the following steps. It includes the consequence of previous studies e.g. VanRaden and Wiggans (1991). Note that the following instruction is approximated; the strict computation excludes the contribution of a daughter to its parent in the parent's EBV.
- Compute $k_{d}=(4-2h^2)/h^2$ (VanRaden and Wiggans 1991).
- Compute the daughter equivalent of EBV: $\mathrm{DE}_{\mathrm{EBV}}=k_{d}\mathrm{REL}_{\mathrm{EBV}}/(1-\mathrm{REL}_{\mathrm{EBV}})$.
- Compute daughter equivalent of PA: $\mathrm{DE}_{\mathrm{PA}}=k_{d}\mathrm{REL}_{\mathrm{PA}}/(1-\mathrm{REL}_{\mathrm{PA}})$.
- Compute the daughter equivalent of daughter contribution (i.e. EBV excluding PA): $\mathrm{DE}_{\mathrm{R}}=\mathrm{DE}_{\mathrm{EBV}}-\mathrm{DE}_{\mathrm{PA}}$.
- Compute the reliability of daughter contribution: $R=\mathrm{DE}_{\mathrm{R}}/(\mathrm{DE}_{\mathrm{R}}+k_{d})$.
- Compute the deregressed proof for this animal: $\mathrm{DRP}=\mathrm{PA}+(\mathrm{EBV}-\mathrm{PA})/R$.
The following AWK script computes the deregressed proof with above procedure.
- pvr_drp.awk
# # Computation of deregressed proof for sires. # # usage: awk -v h2=0.25 -f pvr_drp.awk sol_and_acc > drp.txt # # You can change the relitability as -v h2=value. # The default heritability is 0.25. # BEGIN{ # default h2=0.25 equiv. kd=14 if(h2<=0){ h2=0.25 } kd=(4-2*h2)/h2 print "h2=",h2,"; kd=",kd > "/dev/stderr" } NR>1{ DE_EBV = kd*$5/(1 - $5) DE_PA = kd*$10/(1 - $10) DE_R = DE_EBV - DE_PA R = DE_R/(DE_R + kd) if(R>0){ DRP = $6 + ($4-$6)/R } else { R = 0.0 DRP = 0.0 } print $0,DRP,R }
If you need to compute a cows' deregressed proof, please consult Wiggans et al. (2012; JDS).