More detailed information regarding each selection index is provided in the downloadable document.
Speckle Park International currently reports four different selection indexes. These are the:
- Domestic Maternal Index (DM)
- Domestic Terminal Index (DT)
- Export Maternal Index (ET)
- Export Terminal Index (ET)
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:
- A detailed description of the input costs and value generation of the commercial herd and target production system.
- Once the target production system is described, the BreedObject software evaluates how each trait influences profitability and the economic value of improving each trait.
- 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.
- 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 Speckle Park 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 Speckle Park International 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:
Domestic Maternal Index (DM) - Estimates the genetic differences between animals in net profitability per cow joined for a self-replacing commercial herd that is targeting the supermarket trade. Steers are assumed marketed at 475 kg live weight (260 kg carcase weight and 12 mm fat depth) at 15 months of age. Selected heifers are retained for breeding and the balance marketed at 15 months weighing 450 kg (240 kg carcase weight and 14 mm fat depth). As some daughters are retained, maternal traits are also of importance.
Domestic Terminal Index (DT) - Estimates the genetic differences between animals in net profitability per cow joined in a typical commercial herd that is targeting the supermarket trade. All progeny target the supermarket trade at 450 kg live weight (290 kg carcase weight and 10 mm fat depth) at 18 months of age.
Export Maternal Index (EM) - Estimates the genetic differences between animals in net profitability per cow joined for a self-replacing commercial Bos indicus herd that uses Speckle Park bulls to target the export market. Steers are assumed marketed at 680 kg live weight (375 kg carcase weight and 9 mm fat depth) at 24 months of age. Selected heifers are retained for breeding and the balance marketed at 24 months weighing 500 kg (270 kg carcase weight and 11 mm fat depth). As some daughters are retained, maternal traits are also of importance. This index would also suit commercial Bos taurus herds that are targeting the export market.
Export Terminal Index (ET) - Estimates the genetic differences between animals in net profitability per cow joined in a typical commercial Bos indicus herd that uses Speckle Park bulls and markets all progeny. All progeny target the export market at 550 kg live weight (300 kg carcase weight and 11 mm fat depth) at 24 months of age. This index would also suit commercial Bos taurus herds that are targeting the export market.
More detailed information regarding each selection index is provided in the downloadable document.
If you have any further queries regarding the Speckle Park International Selection Indexes, please do not hesitate to contact staff at your BREEDPLAN processing centre.