Ontwikkelingen in inteelt en verwantschap in de Hollandse Herder: Stand van zaken in 2021 na het toestaan van variëteitskruisingen

The Dutch Shepherd (Hollandse herder) is one of the oldest pedigreed dog breeds in The Netherlands. Three varieties are distinguished: Short hair, Rough hair and Long hair. The rate of inbreeding considerably exceeded the safe limit of 0.5% increase per generation. The total number of pups born per year has decreased, especially for the Long hair and Rough hair. Moreover, there was a decrease in pups born per litter for these two varieties. Until 2014 mating between varieties was not allowed, except sparingly between the Short hair and Long hair varieties. Since 2014 crosses between dogs of the different varieties are allowed. This resulted in a decrease in inbreeding levels for all three varieties and an increase in number of pups born per litter as well, especially for the Short hair. Crossing varieties thus had a beneficial effect both on litter size and for management of inbreeding. More research can indicate how crossing varieties should be used in the future for a sustainable inbreeding policy.