Angus on Dairy RESEARCH Index ($AxD)
Selection Index Summary
- Terminal breeding program where Angus bulls are used over milking dairy cows
- All progeny, both male and female are slaughtered
- Focus on calving ease, in growth, carcase yield and eating quality
- No emphasis is given to fertility or maternal traits
The Angus on Dairy RESEARCH Index ($AxD) is designed for situations where Angus bulls are being used as a terminal sire over milking dairy cows, and all progeny, both male and female, are slaughtered.
The Angus on Dairy RESEARCH index focuses on calving ease, growth, carcass yield and eating quality.
Daughters are not retained for breeding and therefore no emphasis is given to fertility or maternal traits.
Trait Contributions
Figure 1 shows the traits that are considered in the $AxD RESEARCH index, and how much they contribute to the overall balance of the selection index. The larger the segment, the greater the impact on the selection index.
Selection Advantage
Figure 2 shows the selection advantage if animals are selected using the $AxD RESEARCH Index.
The selection advantage is calculated by ranking well used sires within the Angus breed on the $AxD RESEARCH index and comparing the average EBVs of the sires in the highest 10% with the average EBVs of all sires from which they were selected. For example, the sires ranked in the highest 10% based on the $AxD RESEARCH index had a 1.1kg lighter Birthweight EBV and a 13.4kg higher 400 Day Weight EBV than the average EBVs of the sires from which they were selected.
The selection advantage is indicative of the relativity of response that will occur in individual traits if selection is based on the $AxD RESEARCH index. The actual response that is observed will vary depending on the features of the individual breeding program.
