Imaginings of a Livestock Geneticist

Impact of Genotyping Parents/Sibs on the H Matrix

As outlined in the previous section, the H combines pedigree and genomic relationship information into a single relationship matrix The H matrix can be seen as a projection of G on the rest of the individuals (i.e. non-genotyped), such that if parents of two animals are related through G they should also be related in A. Once an understanding of the combined relationship matrix is understood the next logical question is "Who do I need to genotype to reap the maximum genetic improvement?". This is easiest to see in the context of a full-sib family. Outlined below is a subset of different scenarios and the associated relationship matrix:

No Genotypes
Sire Dam FS1 FS2 FS3 FS4 FS5 FS6 FS7 FS8
Sire 1.0 0.0625 0.53125 0.53125 0.53125 0.53125 0.53125 0.53125 0.53125 0.53125
Dam - 1.00 0.53125 0.53125 0.53125 0.53125 0.53125 0.53125 0.53125 0.53125
FS1 - - 1.03125 0.53125 0.53125 0.53125 0.53125 0.53125 0.53125 0.53125
FS2 - - - 1.03125 0.531250.53125 0.53125 0.53125 0.53125 0.53125
FS3 ---- 1.03125 0.53125 0.53125 0.53125 0.531250.53125
FS4 ----- 1.031250.53125 0.53125 0.53125 0.53125
FS5 ------ 1.03125 0.53125 0.531250.53125
FS6 ------- 1.03125 0.53125 0.53125
FS7 -------- 1.03125 0.53125
FS8 --------- 1.03125
Genotype Parents
Sire Dam FS1 FS2 FS3 FS4 FS5 FS6 FS7 FS8
Sire 0.9828600 0.0503414 0.516905 0.516905 0.516905 0.516905 0.516905 0.516905 0.516905 0.516905
Dam - 1.0036 0.526972 0.526972 0.526972 0.526972 0.526972 0.526972 0.526972 0.526972
FS1 - - 1.0219400.521938 0.521938 0.521938 0.5219380.521938 0.521938 0.521938
FS2 - -- 1.0219400.521938 0.521938 0.521938 0.5219380.521938 0.521938
FS3 ---- 1.0219400.521938 0.521938 0.5219380.5219380.521938
FS4 ----- 1.0219400.521938 0.521938 0.5219380.521938
FS5 ------ 1.0219400.521938 0.521938 0.521938
FS6 ------- 1.0219400.521938 0.521938
FS7 -------- 1.0219400.521938
FS8 --------- 1.021940
Genotype Parents and FS1
Sire Dam FS1 FS2 FS3 FS4 FS5 FS6 FS7 FS8
Sire 0.9827450 0.0503219 0.539125 0.516838 0.516838 0.516838 0.516838 0.516838 0.516838 0.516838
Dam - 1.00349 0.562638 0.526904 0.526904 0.526904 0.526904 0.526904 0.526904 0.526904
FS1 - - 1.063020 0.550882 0.550882 0.550882 0.550882 0.550882 0.550882 0.550882
FS2 - -- 1.0218700.521871 0.521871 0.521871 0.5218710.521871 0.521871
FS3 ---- 1.0218700.521871 0.521871 0.5218710.5218710.521871
FS4 ----- 1.0218700.521871 0.521871 0.5218710.521871
FS5 ------ 1.0218700.521871 0.521871 0.521871
FS6 ------- 1.0218700.521871 0.521871
FS7 -------- 1.0218700.521871
FS8 --------- 1.021870
Genotype Parents and FS1 -FS4
Sire Dam FS1 FS2 FS3 FS4 FS5 FS6 FS7 FS8
Sire 0.9823880 0.0508921 0.538908 0.556034 0.431436 0.568873 0.516334 0.516334 0.516334 0.516334
Dam - 1.0031200 0.562413 0.574346 0.554381 0.513188 0.527007 0.527007 0.527007 0.527007
FS1 - - 1.062630 0.878281 0.676297 0.66221 0.550661 0.550661 0.550661 0.550661
FS2 - -- 1.1881600.760513 0.724253 0.565190 0.5651900.565190 0.565190
FS3 ---- 0.9733740.509561 0.4929090.4929090.4929090.492909
FS4 ----- 1.031510.541030 0.541030 0.541030 0.541030
FS5 ------ 1.021670.52167 0.52167 0.52167
FS6 ------- 1.021670.52167 0.52167
FS7 -------- 1.021670.52167
FS8 --------- 1.02167
Genotype Parents and All Offspring
Sire Dam FS1 FS2 FS3 FS4 FS5 FS6 FS7 FS8
Sire 0.981974 0.0508118 0.538640 0.555759 0.431208 0.568593 0.560757 0.562865 0.543506 0.473746
Dam - 1.0027 0.562135 0.574064 0.554107 0.512929 0.497826 0.500972 0.519766 0.547333
FS1 - - 1.062190 0.896142 0.683608 0.661895 0.816531 0.703663 0.802395 0.863961
FS2 - -- 1.187670.748716 0.714282 0.919558 0.7674990.957589 0.738593
FS3 ---- 0.9729640.509304 0.7285650.4078060.7899540.570699
FS4 ----- 1.0310800.632105 0.693128 0.737616 0.512132
FS5 ------ 1.0807900.644025 0.939294 0.675032
FS6 ------- 1.056440.591918 0.657556
FS7 -------- 1.1311000.636207
FS8 --------- 0.972667
References