an estimate of this genetic quality
The genetic ability or merit of an animal for a given trait, for example, secreting milk. One-half of this genetic ability is transmitted to offspring.
In quantitative genetics, the part of the deviation of an individual phenotype from the population mean that is due to the additive effects of alleles. In practical terms: if an animal is mated with a random sample of animals from a population, that animal's breeding value for a certain trait is twice the average deviation of its offspring from the population mean for that trait.