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

The Murray Grey Beef Cattle Society currently reports five different selection indexes. These are the:

• Vealer Terminal Index (VT)
• Supermarket Index (SUP)
• Heavy Grass Fed Steer Index (GF)
• Northern Terminal Index (NT)
• Breeder Replacement (BR)

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 Murray Grey 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 Australian Murray Grey 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:

Vealer Terminal Index (VT) - Estimates the genetic differences between animals in net profitability per cow joined for a typical crossbred commercial herd using Murray Grey bulls to target vealer production. Vealers are finished on grass and target 430 kg live weight (225 kg HSCW and 9 mm P8 fat depth) at 12 months of age. Daughters are NOT retained for breeding and thus no consideration is given to maternal traits.

Supermarket Index (SUP) - Estimates the genetic differences between animals in net profitability per cow joined for a typical Murray Grey commercial herd targeting production of steers for the domestic supermarket trade. Selected heifers are retained for breeding and thus maternal traits are of importance. Steers are either finished on grass, or grain fed for 70 days, and target 470 kg live weight (260 kg HSCW and 12 mm P8 fat) at 15 months of age. In response to industry feedback a premium has been placed on marbling.

Heavy Grass Fed Steer Index (GF) - Estimates the genetic differences between animals in net profitability per cow joined for a typical Murray Grey commercial herd targeting pasture finished steers for heavier grass fed markets. Selected heifers are retained for breeding and thus maternal traits are of importance. Steers target 620 kg live weight (330 kg HSCW and 14 mm P8 fat depth) at 24 months of age. In response to industry feedback a premium has been placed on marbling.

Northern Terminal Index (NT) - Estimates the genetic differences between animals in net profitability per cow joined for a typical commercial herd using Murray Grey bulls over cows containing some Bos indicus content. Steers target 550 kg live weight (300 kg HSCW and 10 mm P8 fat depth) at 27 months of age. In response to industry feedback a premium has been placed on marbling.

Breeder Replacement (BR) - Estimates the genetic differences between animals in net profitability per cow joined for a typical Murray Grey commercial herd targeting the production of weaners or yearlings. Selected heifers are retained for breeding and thus maternal traits are of importance. Steers target 440 kg live weight (230 kg HSCW and 9 mm P8 fat depth) at 12 months of age.

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

If you have any further queries regarding the Australian Murray Grey Selection Indexes, please do not hesitate to contact staff at your BREEDPLAN processing centre.