Australian Breeding Values (ABVs) are the best estimate of a bull’s genetic merit–his ability to pass certain characteristics to his daughters. They have already been calculated for many production and working traits such as milk yield and milking speed by analysing the performance of the bull’s daughters and other family members across many herds. The Australian Dairy Herd Improvement Scheme has now added an estimate of breeding value for resistance to mastitis through the new cell count ABV.

Bulls with lower cell count ABVs will breed daughters with lower milk cell counts.

Half of each bull’s ABV value will be passed on to his daughters (for the daughters the other half will come from their dams).

Because a bull’s cell count ABV is a measure of percentage change, the impact in each herd will depend on the cell count status of the herd. Herds with low cell counts will see smaller changes in absolute terms than herds with high cell counts.