df with random effects
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df with random effects


In the example Ex11a, we have 3 lines and 9 sires,(actually the sires are nested
in the lines). There is 65 observations and 74 animals in total. The addition of
an animal effect or a sire effects does not change the degrees of freedom of the
error (62), which are 65-2-1. The test for lines will be with 2, 62 df with any
number of other random effects?.

If we use Mixed of SAS with a sire model we got 56 df for the denominator
for testing
lines, which comes from deducting 2 df for lines, 9-3 = 6 df for sires/lines
and 1 df for mu. All other things are identical.

Could someone explain the difference in df's?.

Thank you