How Should a Breeder Look at Heritability Estimates?
For a breeder, its simplest use is to decide how effective selection might be, particularly phenotypic selection. For a trait with a very low heritability, selecting on phenotypes directly is not a promising approach. For these kinds of traits, combinations of phenotypes from relatives, such as is achieved through progeny testing, is needed to determine more accurately the underlying genetic merit of the potential parents. When heritability for a trait is high, phenotypic selection will be more effective and obtaining additional information on relatives is of less value than when heritability is low. Methods such as selection indices and best linear unbiased prediction have been developed to combine information from relatives to achieve this goal. The latter method is currently being used in evaluations of livestock such as beef and dairy cattle. John Pollack is a Professor of Animal Genetics at Cornell Animal Sciences Department, working mainly with production species. He teaches both
