Publish date: 8.4.26
The August 2026 Sire Summary introduces several new industry traits designed to give dairy producers a clearer picture of important drivers of dairy success: reproductive performance, calf health, and balanced conformation. These additions provide new opportunities to make genetic progress in areas that impact herd profitability every day. As with any genetic evaluation, these new industry traits are most valuable when used as part of a comprehensive strategic breeding plan based on overall herd goals and existing genetic selection tools.
Use these new industry traits as part of a strategic breeding plan customized for your herd’s goals and genetic priorities.
A New Way to Measure Fertility from CDCB: First Service to Conception (FSC)
Of the new industry traits being introduced, First Service to Conception (FSC) has the most immediate impact for producers focused on reproductive performance. FSC predicts a lactating cow’s genetic ability to conceive after her first insemination, measuring the number of days from the cow’s first service to conception within a lactation, relative to the breed mean. FSC is not a function of voluntary waiting period (VWP), allowing it to account for individual cow management independently of VWP changes. Traditional fertility traits can be influenced by differences in voluntary waiting periods, making it more difficult to compare animals across management systems.
The Benefits of FSC
- Provides a more direct look at conception efficiency after first service
- Complements existing fertility traits such as Daughter Pregnancy Rate and Cow Conception Rate
- Captures fertility performance independent of VWP
- Improves fertility evaluation in herds using extended or custom VWP
- Reflects how cows respond under modern reproductive management systems
- Delivers an interval-based measure of conception efficiency
FSC complements well-established fertility traits such as Daughter Pregnancy Rate (DPR) and Cow Conception Rate (CCR), providing producers with another lens through which to evaluate reproductive performance. It is particularly valuable for herds using varied VWP or a VWP set on a cow basis and offers an interval-based measurement of conception efficiency.
For breeders evaluating FSC, higher values are more desirable because they indicate daughters are expected to conceive sooner after first service. For example, daughters of a bull with a +5 FSC PTA are expected to conceive five days sooner than daughters at the breed average.
Expanding Genetic Selection for Calf Health
Raising healthy replacement heifers remains one of the largest investments dairy producers make. The August 2026 Sire Summary also introduces two new calf health traits from CDCB, for the first time, providing genetic insight into an animal’s expected resistance to common calfhood diseases.
Resistance to Respiratory Problems (RSP)
Respiratory disease continues to be one of the most common and costly health challenges facing young calves. The new Resistance to Respiratory Problems (RSP) trait predicts the expected resistance of an animal’s offspring to respiratory problems in a herd with average management conditions.
By selecting for improved resistance, producers can support healthier calves, protect replacement heifer investments, and contribute to stronger long-term herd profitability and performance. RSP is expressed in percentage points of resistance above or below the breed average. The PTA represents the expected difference in calfhood respiratory resistance among an animal’s offspring. Higher RSP values indicate greater expected resistance to respiratory disease. It might be helpful to think of this as the opposite of incidence percentage.
Resistance to Diarrhea (DIA)
Alongside RSP, the new Resistance to Diarrhea (DIA) trait provides insight into an animal’s expected genetic resistance to calfhood diarrhea, another leading cause of illness and mortality in youngstock. Improving resistance to diarrhea can help reduce the impact of early-life health challenges and support the future productivity and survivability of replacement animals. The goal of DIA is to select genetics with increased resistance to diarrhea and scours, lowering the incidence rate in youngstock.
DIA is expressed in percentage points of resistance above or below the breed average, meaning the PTA represents the expected difference in calfhood diarrhea resistance among an animal’s offspring. Like RSP, larger positive DIA values are more favorable and indicate greater expected resistance.
A New Holstein USA Tool: Holstein Conformation Composite
In addition to the new industry traits from CDCB, Holstein USA is introducing the Holstein Conformation Composite (HCC) as a new selection tool to help breeders find average-sized, balanced Holstein cows by bringing together multiple conformation traits into one selection value. This combination of linear conformation traits identifies animals expected to have balanced frames and udders, with structurally correct feet and legs.
Higher HCC values reflect animals with a linear pattern more closely aligned to the Holstein USA ideal. For producers, HCC can serve as an additional alternative to PTAT (Final Score) when identifying bulls expected to transmit a particular linear pattern.
How Should Producers Use These New Traits?
While the new calf health traits and HCC provide valuable genetic information, they should not be viewed as standalone selection criteria. Instead, they should be incorporated into a customized breeding plan that balances production, fertility, health, longevity, conformation, and overall herd goals. Similarly, FSC should be considered alongside established fertility measures such as DPR, CCR, and Heifer Conception Rate (HCR) to build a comprehensive fertility strategy that drives long-term reproductive performance and genetic progress.
What Does This Mean for ABS Customers?
These new industry traits align closely with ABS’s long-standing focus on fertility, health, and building cows that last and offer future profitability.
- FSC provides producers with an additional tool for improving reproductive performance.
- RSP and DIA bring new genetic insight into calf health and survivability.
- HCC offers another way to think about balanced Holstein conformation.
Together, these traits help producers make more informed breeding decisions in areas that matter every day on the farm: getting cows pregnant efficiently, raising healthier calves, improving long-term herd performance, and selecting for cows built with balance. The information these traits show helps producers, globally, profit from genetic progress.
Ready to incorporate these new industry traits into your breeding strategy? Contact your ABS Representative or complete the form below to profit from genetic progress.
