Genetic progress on dairy farms has accelerated in the last decade, giving producers access to more tools and clearer data than ever before. But with so many indexes, traits and breeding strategies available, choosing the right direction for a herd can feel overwhelming. A new push from extension specialists highlights a simple, producer-friendly message: genetics should match your farm’s goals—not the other way around.
From sire selection to crossbreeding decisions, here’s an overview of the genetic tools producers can use to build a more profitable and resilient herd.
Why Genetics Matter More Than Ever
Sire selection remains the fastest way to make genetic progress in dairy cattle. While cow families and pedigrees still matter, extension specialists note that more than half of a herd’s long-term genetic improvement comes from the bulls a farm uses.
At the same time, many dairies are now making broader breeding decisions—such as selecting breeds for their facilities or crossbreeding to improve fertility and longevity.
Regardless of approach, experts emphasize one starting point: define your genetic goals.
Some farms aim for milk volume, others for component yield, others for health traits or longevity. Clear priorities help producers focus on the traits that produce the most value in their environment.
Understanding the Key Tools: PTA, Reliability, and the Indexes
Modern dairy genetics rely heavily on Predicted Transmitting Abilities (PTA)—estimates of the genetic advantage (or disadvantage) a bull or cow passes on to its offspring.
PTAs exist for dozens of traits, including:
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Milk, fat and protein
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Somatic Cell Score
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Calving ease
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Fertility
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Health traits such as mastitis resistance or metabolic stability
For most traits, zero is the breed average. Positive numbers represent improvement; negative numbers fall below average.
Each PTA comes with a reliability percentage, which increases as more data is collected. High-reliability sires offer more predictable results; younger genomic bulls offer faster progress but with more variation.
Net Merit ($)
Net Merit remains one of the most widely used selection tools for commercial dairy herds. It combines PTAs for multiple economically important traits into a single dollar value representing expected lifetime profitability.
Breed-Specific Indexes
Many breeds also use their own weighted indexes, such as:
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TPI (Total Performance Index) for Holsteins
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JPI (Jersey Performance Index) for Jerseys
These combine production, health, fertility and conformation traits according to breed priorities.
Breed Choice and Crossbreeding: More Options Than Ever
Choosing a breed—or combination of breeds—is one of the biggest genetic decisions a dairy can make.
Breed differences may include:
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Mature body size
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Milk volume
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Component percentages
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Temperament
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Calving ease
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Adaptability to facilities
Crossbreeding is gaining traction on many dairies, particularly for:
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Improved fertility
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Greater longevity
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Reduced health problems
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Enhanced overall hardiness
These advantages stem from heterosis (hybrid vigor), which occurs when two different breeds are mated.
A common approach in North America started with using Jersey sires on Holsteins to improve calving ease and component yield. Today, systems like ProCROSS and rotational breeding offer structured crossbreeding programs.
What to Select For: Profitability and Longevity First
While production remains a major driver of dairy economics, specialists encourage producers to focus on traits that improve lifetime profitability, not just yield in early lactations.
Key considerations include:
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Productive longevity — cows that stay healthier and productive for more lactations
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Fertility traits — vital for maintaining calving intervals and milk flow
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Health traits — such as resistance to mastitis, metritis, ketosis, DA and retained placenta
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Calving traits — ease, stillbirths, and maternal calving traits
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Component yield — especially important in component pricing systems
Producers can also tailor selection strategies to their payment structure.
For example:
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A volume-based market may emphasize milk yield.
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A fat-driven market may prioritize % fat and fat pounds.
Both strategies can be equally profitable depending on the farm’s environment and management approach.
The Bottom Line
Genetic progress doesn’t come from chasing single traits—it comes from setting clear goals and using the right tools. By focusing on reliable indexes, selecting sires that match their operation’s priorities and considering breed or crossbreeding options, dairy producers can build herds that are more productive, more resilient and more profitable over the long term.
