The variability is one of the components of genetic progress and must be considered in all the selection steps. Increasing the inbreeding too quickly would induce a decrease in the expected genetic progress in the affected farms: this is the inbreeding depression, affecting more severely health, hardiness, reproduction… that is to say the functional traits.
The pictogram depicted in the index tables informs you on the easier bulls to use. The lower the parentage level is, the lesser the bull is related to the female population. The pictogram’s posting corresponds to a parentage level lower than 5.3%, indicating the bulls in the upper quarter of this criterion.
As a reminder, the inbreeding percentage of an offspring born from mating first cousins is 6.25%. This also means that the parentage level between two first cousins is 6.25%.