American Milking Shorthorn Society Provides Details on New Policy Changes - Cowsmo

American Milking Shorthorn Society Provides Details on New Policy Changes

The American Milking Shorthorn Society has provided the following statement explaining the new policy changes.

AMSSWe would like to call your attention to a policy change that will take effect over the course of the next 2 years changing one piece of the Genetic Expansion program:

Calves born beginning June 1, 2024 with an EXP sire and an EXP dam will be assigned to the GE herdbook level. Embryos created after August 31, 2023, from an EXP sire and an EXP dam will be assigned to the GE level at birth. The embryo date corresponds approximately to the date that breedings would occur to create June 1, 2024 offspring. Embryos created prior to that date fall under the old policy and maintain the EXP status.

This change does not impact show or award eligibility. Cows holding EXP or higher herdbook status will remain eligible. Additionally, the change does not impact any other herdbook level crosses (GE x full = EXP, EXP x full = full, etc.).

At the 2022 AMSS National Convention held in Champaign, Illinois the AMSS Board of Directors continued over ten years of discussions around breed improvement versus breed identity. All agree the Genetic Expansion program has allowed the breed to improve dramatically and to thrive in today’s world. The program is vital to continued improvements and no discussion of closing the AMSS herdbook has been entertained. However, the drastic herdbook changes that have taken place within our sister breeds (Dairy Shorthorns in UK and Illawarras in Australia) due to low breed percentages, led to deeper discussions regarding our status. The AMSS Board of Directors unanimously decided to reintroduce one of the original rules as a small step in maintaining the Milking Shorthorn breed identity. This step will hopefully prevent the need to take more drastic steps as our sister societies have had to do. We hope to not only maintain the improvements made so far, but also protect the important Milking Shorthorn characteristics that make the Red, White and Roan so great. These include reproductive traits, productive life, hardiness, calving ease, efficiency and overall versatility.

The AMSS Genetic Expansion program was designed by Dr. Clint Meadows of Michigan State University in the 1960’s using Mendelian genetics for percentage calculations. Within his design, any level crossed to the same level (EXP x EXP) was penalized and the offspring were dropped a level (EXP x EXP = GE). This was done to encourage breeders to work back towards higher breed purity. When the initial program was adopted by the AMSS Board of Directors in the early 1980’s any dairy breed outside of Holstein was penalized with an extra step involved in reaching full herdbook status (37000 registration numbers).

At the 2001 AMSS National Convention held in Cortland, New York the AMSS Board of Directors made some major changes to how the Genetic Expansion program worked (with major dissent from some influential breeders). First, the extra step (37000 registration number) requirement for non-Holstein dairy breeds was removed. All dairy breeds were welcomed into the AMSS herdbook at an equal level. Secondly, the penalty for crossing the same herdbook level (EXP x EXP) was removed.

There are six levels within the current AMSS herdbook, initially linked to breed percentages (see below). Recent
calculations of around 700 pedigrees are shown as a comparison.


These numbers include many older animals and genetic lines that have influenced the breed. Looking at the 2022 AMSS Sire Catalog for a smaller example, using currently available genetics, there are 36 full herdbook bulls who average 76.3% Milking Shorthorn and 21 EXP bulls which average 63.1%. These numbers are well under the purity levels that the original genetic expansion plan was aiming for and what Dr. Meadows laid out.

The breeding chart information below will go into effect June 1, 2024.


If you have questions, please do not hesitate to reach out to the office or any AMSS director.
Thank you,
AMSS Board of Directors

President: Marcia Clark (814) 602-7089 [email protected]
Vice-President: Kylie Preisinger (765) 427-6964 [email protected]
Matt Henkes (563) 880-8614 [email protected]
Allen Hess (301) 991-2194 [email protected]
Joanna Landrum (812) 345-2793 [email protected]
Katie Agnew (920) 273-9324 [email protected]
Eddie Hartfield (601) 794-7046 [email protected]
Larry Landsgard (563) 419-5576 [email protected]
Adam Luchterhand (715) 937-2352 [email protected]
Jerry Merrill (607) 437-4622 [email protected]
Darren Ropp (815) 848-3424 [email protected]
Michelle Upchurch (530) 720-2441 [email protected]

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