Page 63 - Linear Models for the Prediction of Animal Breeding Values 3rd Edition
P. 63

The objective is to estimate sex effects and predict breeding values for sires 1, 3 and 4.
                                                                    2
                                                 2
        Using the same parameters as in Section 3.3, s  = 0.25(20) = 5 and s  = 60 − 5 = 55,
                                                 s                  e
        therefore a = 55/5 = 11.

        SETTING UP THE DESIGN MATRICES AND MME
        The design matrix X relating records to sex is as defined in Section 3.3.1. However,
        Z is different and its transpose is:

                 ⎡10 10 0     ⎤
                 ⎢            ⎥
            Z ′ =  0  10 0 1  ⎥
                 ⎢
                 ⎢000 1 0     ⎥ ⎦
                 ⎣
        indicating that sires 1 and 3 have two records each while sire 4 has only one record.
        The vector of observations y is as defined in Section 3.3.1. The matrices X′X, X′Z,
        Z′X, Z′Z, X′y and Z′y in the MME can easily be calculated through matrix multipli-
        cation. Thus:
                  ⎡30  ⎤         ⎡1  11  ⎤
                             ′
              ′
            XX =  ⎢    ⎥  ,  XZ =  ⎢     ⎥  ,  Z′Z = diag(2,2,1), X′y is as in Section 3.3.1
                  ⎣ 02 ⎦         ⎣ 11 0  ⎦
            and the transpose of Z′y = (Z′y)′ = [8.4 7.9  3.5]
        The LSE are:
            ⎡ 30 1 1 1⎤ ⎡ ˆ ⎤     ⎡13.00 ⎤
                              1 b
            ⎢             ⎥ ⎢ ⎢  ⎥  ⎢   ⎥
            ⎢ 02 1 1 0    ⎥  ˆ  2 b ⎢  ⎥  ⎢  6.80 ⎥
            ⎢ 11 2 0 0⎥ ⎢     1 ˆ s ⎥  =   ⎢ 8.40 ⎥
            ⎢             ⎥ ⎢  ⎥  ⎢     ⎥
            ⎢ 11 0 2 0    ⎥ ⎢  3 ˆ s  ⎥  ⎢  7.90 ⎥
            ⎢ ⎣ 1 0001    ⎥ ⎢  4 ˆ s ⎦ ⎥  ⎢ ⎣  3.50 ⎥ ⎦
                          ⎦ ⎣

        Apart from the fact that sire 4 is the son of sire 1, no other relationships exist among
                                −1
        the three sires. Therefore A  for the three sires is:
                 ⎡  1.333 0.0  −0.667⎤
              −1 ⎢                   ⎥
            A  =  ⎢  0.000 1.0  0.000 ⎥
                 ⎢ ⎣ −0.667 0.0  1.333⎥ ⎦

                                       −1
        The MME obtained after adding A a to Z′Z in the LSE are:
             ˆ ⎡  1 b  ⎤ ⎡ 3.000 0.000  1.000  1.000  1.000⎤ − 1  ⎡13.00 ⎤
            ⎢  ⎥ ⎢                                   ⎥    ⎢    ⎥
             ˆ 2 b ⎢  ⎥ ⎢ 0 0.000 2.000  1.000  1.000  0.000 ⎥  ⎢  6.80 ⎥
            ⎢  1 ˆ s ⎥ 1.000 1.000 16.666  0.000 − 7.334⎥ =  ⎢ 8.40 ⎥
                 ⎢
            ⎢  ⎥ ⎢                                   ⎥    ⎢    ⎥
            ⎢  3 ˆ s  ⎥ ⎢ 1.000 11.000  0.000 13.000  0.000 ⎥  ⎢  7.90 ⎥
            ⎢  4 ˆ s ⎣  ⎥ ⎢ 1.000 0.000 − 7.334  0.000 15.666 ⎥ ⎦ ⎦  ⎢ ⎣  3.50 ⎥ ⎦
               ⎦ ⎣

        Univariate Models with One Random Effect                              47
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