Simulated Matings

The Simulated Matings administration screens let you create and manage EPD Lists — named sets of genetic traits used when running simulated mating comparisons. Before you can use the simulated mating tools elsewhere in GEM, at least one EPD List must be created here.

Background: EPDs and Simulated Matings

EPDs (Expected Progeny Differences) are genetic predictions published by breed associations. Each EPD represents the expected difference in offspring performance for a given trait (e.g., birth weight, weaning weight, calving ease) compared to the breed's base population.

GEM's Simulated Mating tools use EPDs to estimate what an offspring would look like if a specific dam were bred to a specific sire. The estimated offspring EPD for each trait is calculated as:

Estimated Offspring EPD = (Sire EPD + Dam EPD) / 2

This lets you evaluate and compare multiple potential sires against a dam (or a set of dams) before making breeding decisions.

EPD Lists are the trait selections that drive these comparisons. An EPD List is a named, ordered set of EPD traits you want to see in simulated mating reports. You can maintain multiple lists — for example, one focused on growth traits and another on calving traits — and choose which list to use at report time.

Where EPD Lists Are Used

Once created here, EPD Lists appear in several places across GEM:

• Animals → Other → Simulated Mating Setup / Simulated Mating — Select a sire set and an EPD list, then view a sire-by-trait matrix showing estimated offspring EPDs for the current dam. Select a sire to record a proposed mating on the animal's record.
• Animal Reports → Simulated Mating — Run the comparison across an entire animal set.
• Animal Reports → Simulated Mating Worksheet — A detailed worksheet view showing every dam × sire combination with estimated offspring EPDs.

New Simulated Mating EPD List

Administration → Simulated Matings → New Simulated Mating EPD List

Creates a new EPD List. The form shows all EPD traits available for your herd (drawn from breed association EPDs, indexes, percentile ranks, and any custom-labeled fields you have configured).

Fields:

Steps:

1. Enter a name for the list.
2. For each EPD trait you want to include, enter a sort order number (e.g., 1, 2, 3…). Traits with a blank sort order are not saved to the list.
3. Click Submit. A confirmation message will appear once the list is saved.

Tip: You can include as many or as few traits as you like. Simpler lists (5–10 key traits) tend to produce cleaner reports than lists with every available EPD.

Edit Simulated Mating EPD List

Administration → Simulated Matings → Edit Simulated Mating EPD List

Modifies the trait selection and sort order for an existing EPD List.

Steps:

1. Select the list you want to edit from the dropdown.
2. The form loads with all available EPD traits. Traits currently in the list will show their saved sort order; others will be blank.
3. Adjust sort orders — add traits by entering a number, remove traits by clearing their sort order field.
4. Click Submit. The list is fully replaced with the new configuration.

Note: Submitting the edit form replaces all previous trait selections for that list. If you clear a sort order that was previously set, that trait is removed from the list.

Delete Simulated Mating EPD List

Administration → Simulated Matings → Delete Simulated Mating EPD List

Permanently removes an EPD List and all of its trait definitions.

Steps:

1. Select the list you want to delete from the dropdown.
2. A confirmation screen will appear showing the list name.
3. Click Submit to confirm. The list and all its saved traits are deleted.

Note: Deleting an EPD List does not affect any proposed mating assignments already recorded on animal records (those are stored separately). It only removes the list definition itself.