The Holstein Association USA is introducing a powerful new genetic selection tool: the Holstein Confirmation Composite (HCC). Developed through years of research and collaboration with producer-led committees, HCC aims to help dairy producers breed more balanced, functional, and profitable Holstein cows with greater longevity.
Jeffrey Bewley, Ph.D., Executive Director of Genetic Programs and Innovation and Jason Graham, Ph.D., Genetic Evaluation and Research Scientist at Holstein Association USA, shared insights into the development and future impact of HCC.
What Is the Holstein Confirmation Composite (HCC)?
The Holstein Confirmation Composite is a new genetic evaluation designed to identify cows that combine:
Unlike traditional type evaluations that often reward extremes, HCC focuses on achieving optimal balance across 18 linear type traits.
The concept originated from Holstein breeders themselves. Through the Holstein Association's Genetic Advancement Committee and Conformation Advisory Committee, producers expressed a need for a better metric to define the ideal modern Holstein cow.
Why Was HCC Developed?
For decades, dairy breeding programs often selected for traits in a linear fashion, assuming "more is better." However, experience has shown that pushing certain traits to extremes can create unintended consequences.
Examples discussed in the podcast include:
Rear leg side view: Selection for straighter legs eventually produced overly post-legged cows.
Teat length: Continuous selection for shorter teats ultimately created cows with teats that became too short for optimal management.
Stature: Ongoing emphasis on larger cows may have exceeded the most efficient biological and economic size.
The HCC was developed to address these challenges by identifying the optimal range for each trait instead of continuously selecting for extremes.
How HCC Differs from Traditional Type Selection
A key innovation behind HCC is its mathematical design.
According to Graham, HCC uses a penalty-based approach rather than a simple weighted sum of traits. Each of the 18 linear traits is evaluated against a functional optimum. The farther a sire deviates from that optimum, the greater the penalty applied.
This creates a breeding tool that:
Rewards balance rather than extremes
Accounts for genetic correlations among traits
Promotes cattle that are functional and sustainable
Supports long-term profitability
The result is a more holistic evaluation of dairy cow conformation.
The Importance of Genetic Correlations
One of the most complex challenges in developing HCC was understanding how traits interact genetically.
The Holstein Association analyzed data from more than one million cows, evaluating relationships among all 18 type traits, production records, and longevity indicators.
Researchers examined approximately 150 genetic correlations, ensuring that selection pressure on one trait would not unintentionally create problems elsewhere.
One example highlighted was the relationship between:
Rear udder height
Rear udder width
Stature
Selecting aggressively for higher and wider rear udders can unintentionally produce taller cows. HCC helps manage those relationships, allowing breeders to improve udder quality while maintaining a moderate-sized animal.
Traits Included in HCC
The Holstein Confirmation Composite incorporates all 18 linear type traits.
Key breeding objectives include:
HCC and Cow Longevity
One of the primary goals behind HCC is improving productive life.
A significant finding from the research was the relationship between conformation and longevity.
While traditional PTAT (Predicted Transmitting Ability for Type) has a slightly negative genetic relationship with productive life, HCC was designed to have a positive relationship with traits associated with:
Productive life
Livability
Fertility
Overall fitness
This makes HCC particularly valuable for producers focused on creating cows that remain productive in the herd longer.
HCC vs. PTAT: Understanding the Difference
HCC is not intended to replace PTAT. Instead, it provides breeders with another tool for specific breeding goals.
PTAT Focuses On:
HCC Focuses On:
Many breeders may choose to use both together, while others may prefer HCC if their primary objective is long-term functionality and cow wellness.
How Producers Can Use HCC
Bewley and Graham emphasized that HCC should complement existing genetic indexes rather than replace them.
A practical approach may be to:
Use HCC to identify sires with desirable conformation.
Combine HCC with HHP$®
, TPI®, NM$ or DWP$®.
Build mating programs that maintain production, health, and fertility while improving functional type.
HCC Release Timeline
Holstein Association USA plans to introduce HCC in two phases:
Once implemented, HCC values will be published alongside routine genetic evaluations.