More detailed information regarding each selection index is provided in the downloadable document.

New Zealand Herefords currently reports three different selection indexes. These are the:

• Hereford Prime Index
• Beef Heifer Index
• Dairy Beef Index

All of the selection indexes described above have been derived using BreedObject software. The BreedObject selection index development process involves four major steps. These steps are:

1. A detailed description of the input costs and value generation of the commercial herd and target production system.
2. Once the target production system is described, the BreedObject software evaluates how each trait influences profitability and the economic value of improving each trait.
3. The BreedObject software then assesses what emphasis needs to be applied to each Estimated Breeding Value (EBV) trait to achieve the maximum profitability in the production system and for the market end point for which that index was designed. This step includes evaluating the selection response expected from direct selection on the individual EBVs and the correlated responses expected from selection on related EBVs.
4. The importance placed on each EBV results in the selection index value that is calculated for each animal.

Each selection index describes a different production system/market scenario and relates to a typical commercial herd using New Zealand Hereford bulls. As is the case for EBVs, each selection index can be used to rank and compare animals on their genetic merit. Producers are advised to use the selection index that most closely aligns to their production system. See the Using New Zealand Hereford Selection Indexes tip sheet, available in the Help Centre on the BREEDPLAN website, for further information on the identification and utilisation of the most applicable selection index for your herd.

All selection indexes are reported in units of net profitability per cow mated ($) for the production system/market scenario they describe. Selection indexes account for both sides of the profit equation (costs as well as income), and also reflect the relative short and long term profit associated with possible selection decisions. For example, short term profit can be generated by a bull through the sale of his progeny, and the longer term profit generated by his daughters in a self-replacing cow herd.

Each of the selection indexes are focused on efficient beef production while also targeting the following specifications:

Hereford Prime Index - Estimates the genetic differences between animals in net profitability per mixed age cow joined for a typical self-replacing commercial herd where Hereford bulls are joined to either Hereford or other British breed females and targeting the production of grass finished steers for the Hereford Prime program. Selected heifers are retained for breeding and so maternal traits are of importance. Steers target 550 kg live weight (300 kg carcase weight & 7 mm P8 fat) at 20 months of age, and heifers 475 kg (260 kg carcase weight & 8 mm fat depth), at 22 months of age.

Beef Heifer Index - Estimates the genetic differences between animals in net profitability per yearling heifer joined for a typical self-replacing commercial herd where Hereford bulls are joined to either Hereford or other British breed heifers. Selected heifers are retained for breeding and so maternal traits are of importance. Steers target 510 kg live weight (280 kg HSCW and 7 mm P8 fat depth) and heifers 450 kg (250 kg HSCW and 8 mm P8 fat depth) at 20 months of age.

Dairy Beef Index - Estimates the genetic differences between animals in net profitability per mixed age dairy cow joined with all progeny destined for slaughter. Steers and heifer progeny target 550 kg live weight (300 kg carcase weight and 6 mm fat depth) at 24 months of age and at 475 kg live weight (260 kg carcase weight and 7 mm fat depth) at 22 months, respectively.

More detailed information regarding each selection index is provided in the downloadable document.

If you have any further queries regarding the New Zealand Hereford Selection Indexes, please do not hesitate to contact staff at New Zealand Herefords.