Interbull have an animal evaluation system which collates sire breeding values from all around the world. The relevance of how a bull’s daughters are performing overseas depends on how similar the environment and farming systems are between NZ, and the home country of each daughter.
Most dairy farms in New Zealand are predominately pasture based, and almost all NZ dairy cows graze pasture every day of the year. This makes our farming conditions somewhat unique, which means genetics that work overseas do not necessarily work well here.
Interbull account for the relationship between NZ and other countries, and then use daughter information from around the world as best they can to create NZ specific breeding values.
These breeding values are received by NZAEL after each Interbull AE run (three times each year).
Because of the differences between NZ and other countries, Interbull breeding values on the NZ scale often have low accuracy. As a bull accumulates daughters in NZ, the performance information will be gradually blended with Interbull breeding values, until the international data is disregarded and the BVs are based entirely on the performance of a bull’s NZ born daughters.