The average length of time between the birth of an animal and the birth of the progeny replacing that animal in the breeding herd. Genetic Correlation A relationship between two traits that arises because some of the same genes affect both traits. The genetic worth of an animal for a given trait. The increase in average genetic merit of a population for any particular trait as a result of selective breeding. The rate of progress is increased when accuracy, selection intensity or heritability increase or when generation interval decreases.
Genetic progress is found as the change in mean estimated breeding value over time.
Genotype The actual genetic make-up or blueprint of an animal as determined by its genes. The change in performance of different genotypes from one environment to another. Superiority of breed B is greater with a high level of nutrition than with a low level. Half-Sibs Individuals having either the same sire or the same dam but not both. The transmission of characteristics from parents to offspring through genes.