Graduates from the scheme gain their proofs from the first lactation of their daughters in herds around the country.
The bulls in the scheme come from three breeds — Holstein-Friesian, Jersey and KiwiCross. We select and rear the bulls, and we partner with top farmers around the country to evaluate their breeding worth.
Selecting male calves to join the scheme
Each year we identify about 1700 male calves from highly productive cow families with the potential to join the Sire Proving Scheme. We use DNA tests to select about 200 with the most desirable genetic traits. Some of the most important traits include:
- fat production
- protein production
- udder support.
These 200 genomically selected calves join the Sire Proving Scheme and spend the next four years grazing on our bull farms in Newstead and Awahuri.
Inseminating cows on participating farms
When the male calves are a year old we collect their semen and use it to inseminate cows on the farms involved in the Sire Proving Scheme. After calving, all the daughters are matched to their correct sire using DNA parentage testing to make sure we collect the most accurate data about each bull in the scheme.
Calving the daughters and measuring their performance
The next stage of the process is to get the daughters in-calf. Once the daughters have calved and start lactating we measure their productivity through regular herd testing.
We collect other information about the daughters during their first lactation, including:
- traits other than production (TOP)
- live weight
- calving difficulties
- calf defects
- non-return rates
- culls and losses.
Getting proofs for the bulls
We get proofs for the bulls using information from their daughters’ first lactation. We use the proofs to identify about 20 top-performing bulls which we add to our Premier Sires teams and include on our list of Alpha bulls.
We continue to monitor the bulls’ performance after they have graduated from the Sire Proving Scheme.