Building effective systems to manage inbreeding in pedigree dog breeds
A new approach to delivering advice on inbreeding in pedigree dog populations is developed by tracking the relative importance of components of the sum of squared genetic contributions. Using pedigree data from 12 dog breeds, contributions of animals born in 1990 to animals born in subsequent years (1991 to 2012) were calculated. The proportion of variance attributable to the mean, the regression of 'final' on 'current' contributions and the residuals were plotted using barycentric coordinates showing the relative importance of each. Results showed that variance due to regression, indicating the predictive ability of 'ultimate' by 'early' contributions, was increasingly predominant over time. Differences in the rate that this occurred were apparent across sexes and breeds. Results indicate that it is feasible to both make reasonable predictions of ultimate contributions and at what ages such predictions become useful, and to develop a dynamic tool for informing breeders using this approach.