Erling is professor in Animal Breeding and Genetics and head of the department of Animal Breeding and Genetics since 2008. He has a PhD from SLU on breeding programs to improve lifetime performance of dairy cattle. During the last 20 years he has been involved in several projects that have been aimed at quantifying the amount of genetic variation (and covariation) in various types of traits in various species. The traits studied have been fertility, health, behaviour, maternal ability, performance or production, and longevity; and the species dairy cattle, pigs, poultry, horses, and dogs. Examples of research in dairy cattle includes using survival analysis for the study of longevity, fertility and mastitis, and using random regressions for the analysis of genotype by environment interaction (reaction norms). He is Interbull Secretary since 2011.