Terminal Sire Index

The AICA Terminal Sire Index (TSI) utilizes economic and management descriptions of your ranching operation, along with EPD on available Charolais bulls to assist in identifying the most profitable sires for your unique operation. Using economic selection index theory, this tool will generate dollar indexes per terminal progeny produced on bulls in the AICA database, ranking them for profit potential given the inputs you provide. The dollar indexes are to be interpreted much like single trait EPD. For example, if sire A's index is $191.66 and sire B's index is $200.00, then we would expect Sire B's offspring to average $8.34 more net return ($200.00 - $191.66) than sire A's offspring.

This program assumes all offspring are marketed based upon carcass value and replacement females are purchased or raised as a separate enterprise. Inputs should be provided based on historical information from your operation. The TSI economic default value is based on a three year rolling averaged utilizing USDA data.

It is important to remember that this is a Terminal Sire Index and should not be used as the sole selection tool for producing replacement females. Producers should consider the appropriate traits for the selection of sires to produce replacement females.


In an ideal selection scheme producers would select breeding animals that excel in all traits. In reality though, this is not the case. Producers often find it necessary to make compromises in selection to balance the strengths and weaknesses among selection candidates. This is driven by the fact that unfavorable relationships exist between traits. Therefore, it is difficult for producers to weigh all the options appropriately given the various management programs and diversity among beef cattle. To make this decision even more challenging is the fact that not all producers sell beef cattle based on the same marketing grid.

A selection index is a formal method of combining Expected Progeny Differences (EPD) for different traits into one single value on which to base selection decisions. The AICA Terminal Sire Index uses estimates of the genetic relationships between traits and breeder historical input data on the cow herd a sire is to be mated along with marketing and carcass grid specifications to determine economic values to use in the index. These economic values are then multiplied by the EPD and summed to produce an overall index value for each animal for the selected scenario. This index places economic value on the various traits that are important to the given scenario.

The AICA Terminal Sire Index is unique in that it does not always return the same index value unless the herd profile and marketing scenario remains unchanged. This gives each producer the opportunity to customize the index by inputting herd profile data that may be unique to their operation. Remember though that this is a Terminal Sire Index and does not indicate which sires would be the most profitable when retaining replacement females. Factors other than what are used in the index are important considerations for replacement females.

Producers also must use realistic information when inputting your herd and marketing profile. To illustrate this, try changing one of the variables in the profile without changing any of the others. For example, if all other profile data is unchanged and weaning weight is increased to an unrealistic value of 1000 pounds the index returns the lowest growth bulls available. This is because with the increased weaning weight and the length of the back grounding and feeding phases a producer would receive huge discounts based on overweight carcasses at harvest. One of the major benefits of this index is its ability to help match genetics to management programs.

Sire Listing Criteria
For bulls to have a Terminal Sire Index they must be registered with the American-International Charolais Association. Each bull must also have an EPD for BWT, WWT, YWT, MAT, REA, HCW, MARB and FAT.

PROGENY PROVEN SIRES: Must have sired at least 3 calves with performance data reported to AICA within the last two years and an accuracy value of .30 or higher.

UNPROVEN SIRES: 30 months of age or younger.

American-International Charolais Association
11700 NW Plaza Circle  |  Kansas City, MO 64153
Phone: 816-464-5977  |  Fax: 816-464-5759
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