Ten selection indexes are published for animals within the TransTasman Angus Cattle Evaluation.
The majority of selection indexes are maternal selection indexes and are designed for use in a self replacing breeding program where a portion of female progeny are retained as replacements. The exception is the Angus Terminal Sire Index which is designed for use in situations where Angus bulls are being used as a terminal sire over mature breeding females and all progeny, both male and female, are slaughtered.
The Angus Breeding and Angus Breeding Low Feed Cost selection indexes are general purpose selection indexes that are suitable for use in the majority of commercial beef operations.
The Domestic, Domestic Low Feed Cost, Heavy Grain, Heavy Grain Low Feed Cost, Heavy Grass, Heavy Grass Low Feed Cost and AngusPRO selection indexes are specific to beef operations targeting a defined market endpoint with their steer progeny.
The Angus Breeding, Domestic, Heavy Grain, Heavy Grass, AngusPRO and Angus Terminal selection indexes are designed for use in a production system where pasture is fully utilised for the majority of the year.
The Angus Breeding Low Feed Cost, Domestic Low Feed Cost, Heavy Grain Low Feed Cost and Heavy Grass Low Feed Cost selection indexes are suitable for use in production systems where pasture is not fully utilised for the majority of the year, or the cost of supplying additional feed is low, and hence, where an increase in the maintenance requirements of the mature female breeding herd results in minimal additional costs being incurred. The low feed cost versions of these selection indexes do not consequently aim to limit any increase in mature cow weight, which is an objective in the other versions of these selection indexes.