$INDEX is a module that combines the EBVs produced by PIGBLUP into a single index value based on the costs of production and the marketing data supplied by the breeder. These data include information on:
In the event that some breeders do not have this information, the program provides substitute values which represent averages for the Australian industry. The $INDEX therefore links EBVs for economic traits together with key commercial information. $INDEX thus becomes a powerful decision making tool.
The $INDEX operates by considering two sub-objectives of the pig's life cycle (the growing-finishing sub-objective and the sow sub-objective). To define costs and returns in the growing-finishing sheds, the growing-finishing sub-objective uses economic and production inputs to define costs and returns so that the value of the production traits for each pig can be determined. The EBV for reproduction (NBA) can be valued by the sow sub-objective determining the costs and returns for the production of an additional pig. These two sub-objectives are then combined into a single overall objective - the $EBV value - depending on the relative emphasis of maternal or terminal sire lines.
PIGBLUP allows breeders producing seedstock to develop selection indices for the buyers of that seedstock. Therefore, you can use the economic situation of the buyer to rank your animals specifically for that client.
The same options that are applicable to the breeder's own index apply to that of the client whilst using the client's economic data or using weights for the EBVs provided by the client.
It is possible to install a number of different clients within a breed in PIGBLUP.
An option exists to combine all EBVs with user-supplied (economic) weights. This can be done in addition to any $INDEX calculation.