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We continue the example with the rabbits. It appeared that even though the rabbits were supposed to have been weighed at 3 months of age, this was not always the case. Due to holidays and weekends, some animals were weighed a bit younger and some a bit older. You can imagine that this has influenced the heritability because there was variation due to age that will have increased the error variance, and thus decreased the heritability. And remember, the closer to 1 the heritability is, the better the phenotype represents the underlying genetic superiority. The management was changed and now all rabbits were weighed at exactly 3 months of age and the heritability increased from 0.3 to 0.4. Consequently, we are better able to predict the underlying genetic superiority of the animal and the EBV increased to 0.4*0.3 = 0.12 kg.
Thus:
The EBV using own performance can be estimated as: EBVmass selection = h2 * (P-Pmean) |