Page 182 - Linear Models for the Prediction of Animal Breeding Values 3rd Edition
P. 182

The matrix X is formed as discussed in Example 3.1, Z is an identity matrix and
         the matrix W is:
                 ⎡11 0    0   0  0  0  0  0  0⎤
                 ⎢                            ⎥
                 ⎢ 0  0 1 1 0    0  0  0  0  0 ⎥
            W = ⎢0  0   0  0 1 1 0     0  0  0⎥
                 ⎢                            ⎥
                 ⎢ ⎢ 0  0  0  0  0  0 1 1 0  0 ⎥
                 ⎢ ⎣ 0  0  0  0  0  0  0  0 1 1 ⎥ ⎦


                      −1
                             −1
         The matrices A  and G  have been calculated for the example data. The remaining
                      u      v
         matrices in the MME are calculated through matrix multiplication and addition. The
         MME are too large to be shown, but solving the equations by direct inversion gives
         the following results:

                         Effects                   Solutions
                         Sex
                           Male                     7.357
                           Female                   5.529
                         Animals                   Breeding values
                           1                        0.092
                           2                       −0.091
                           3                        0.341
                           4                        0.329
                           5                        0.515
                         MQTL alleles of animals   Additive effects
                           1p                       0.064
                           1m                       0.011
                           2p                      −0.065
                           2m                      −0.011
                           3p                       0.083
                           3m                      −0.004
                           4p                       0.028
                           4m                       0.076
                           5p                       0.043
                           5m                       0.086



         The additive genetic effects of the MQTL accounted for about 45% of the total
         genetic merit of animals 1 and 2 but only about 20% for animals 3 and 5.
            In Germany, with Holstein dairy cattle, the method used in Example 10.2 has
         been used to incorporate QTL information into routine estimation of breeding values
         (Szyda et al., 2003). In the study, 13 markers were used for routine genotyping of
         animals, and regions representing QTL for milk, protein, fat yields and somatic cell
         counts were identified on several chromosomes. The QTL information has been
         incorporated into BLUP, analysing DYD as the dependent variable. As a percentage
         of the polygenic variance, the variances of the MQTL in their study varied from 3 to
         5% for milk, fat and protein yields in the first lactation.


          166                                                            Chapter 10
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