There is certainly nothing new in saying that inbreeding, the mating of related individuals, has negative consequences in farmed animal populations. Inbreeding leads to loss of genetic variation and most importantly to reductions in performance (i.e. inbreeding depression) particularly in traits related with fitness such as fertility and viability. Reductions in fitness traits can eventually make further progress imposible despite the presence of genetic variance. Even large populations are experiencing large increases in the rates at which inbreeding accumulates. Examples include US and UK Holstein dairy cattle populations where the worldwide use of few elite sires is leading to current rates much higher than those observed in the past and where deteriorations in health and reproductive traits have been observed. Broadening the breeding objectives for livestock species (Simm et al., 2001) would alleviate this but still effective methods for controlling inbreeding need to be applied.