A Multiplicative Random Regression Model for Test-Day Data with Heterogeneous Variance
نویسندگان
چکیده
Finnish genetic evaluation of dairy cattle is based on test-day (TD) yields, applying a multiple-trait random regression TD model. The model considers the first lactation milk, protein, and fat yield, plus the later lactation milk, protein, and fat yield as different traits, where all the later lactations are modelled as repeated observations (Lidauer et al., 2000). Currently, yields are scaled to correct for differences in variance among later lactations. Heterogeneous variance among herdtest-days (HTD) and time is ignored.
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