This is probably a long way down the track. Breeding programmes for long lived species with big intergenerational gaps and large birth intervals (eg. white rhino and elephant) tend to follow a breeding programme of exhausting all foudner option (Gung, Putra Mas and Bong Su), before then looking at males from the first generation (Luk Chai etc.). These first generation males are usually bred later in life, while the necessity of breeding cows at a young age (for reproductive and biological reasons) mean that breeding of first generation females cannot be delayed in the same way. Any of these females can still be bred to one of the two founder males that is not their father.