Breeding Worth (BW) is the index that we use to rank cows and bulls according to their ability to meet this objective.
Breeding Worth explained
BW ranks bulls and cows on their expected ability to breed profitable and efficient replacements. BW is calculated by combining breeding values with the appropriate economic values.
- Breeding Values (BV): An estimate of a cow or bull's genetic merit for a trait. e.g. Will his or her daughters produce milk solids efficiently, and be robust herd members?
- Economic Values (EV): An estimate of the value of a trait to a NZ dairy farmer.
There are now eight traits directly included in Breeding Worth with Body Condition Score added in February 2016.
These are traits which have been identified as having a direct economic value. In addition to this, there are a range of other traits which are used to improve our estimations, such as udder overall, which is used to help predict cow survival.
Breeding Worth update: February 2016
Changes to Breeding Worth (BW) are now in place following the 15 February Animal Evaluation run.
During this run, a range of developments were rolled out, some of which were routine, such as an update to the economic values, and some of which were fundamental improvements to the AE system.
Improvements included the addition of the Body Condition Score trait to Breeding Worth, a change to the model that drives the fertility breeding value, and the introduction of a 'reproof bias adjustment'.
These developments enable us to provide farmers with the best information available to make their 2016 breeding decisions.