The situation for Sire (Family) models seems to be a bit better. Generalised Linear Mixed Models (GLMM) procedures in ASReml (which use the Schall method) may be seriously biased when applied to animal models. It seems to be easier starting on binary data and David Collett’s book Modelling Binary Data is an excellent starting point. Another good source is Steve Kachman’s work. There are papers that use ASReml, like Southey et al. Are there any good references regarding generalized mixed models, particularly for genetic analysis? For example, the variance of the logit link is: pi*pi/3 (i.e., approximately 3.29). Basically you use the variance of the link function as the residual variance. This is in the old manuals for the logistic models. Just as you would a normally distributed trait. How does one calculate heritability for binomial or poisson models? The following explanation is based on emails by Bruce Southey and Arthur Gilmour.
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