The authors are industry analysts with CoBank.
Genetic improvements within the U.S. dairy herd are fueling historic gains in key milk components needed to produce cheese, butter and a variety of other popular dairy foods. While U.S. fluid milk production has remained relatively flat in recent years, butterfat and protein levels within the nation’s milk supply are growing at a record pace as more producers are employing genetics to optimize milk composition.
There are two main drivers that will continue to push butterfat and protein content on U.S. dairy farms toward new records well into the future. The first is breeding for improved butterfat and protein, which rank among the most heritable traits for dairy cows. Second is multiple component pricing (MCP), which places nearly 90% of the milk check value on butterfat and protein, and over 90% of farm gate milk is priced on MCP principles. As dairy farmers select for more components through their genetics programs, there is untapped potential for how high those percentages can go, further improving their milk checks.
New records abound
The combination of genetics and market incentives have propelled milkfat and protein to record levels both on a percentage and per-pound basis. Butterfat posted the fourth-straight annual record when evaluating data going back over a century. In 2021, milkfat broke through the 4% ceiling and bested a 76-year-old record that stood since the close of World War II. In 2024, butterfat levels charged even higher to average 4.23% nationally, based on calculations using monthly data from USDA’s National Agricultural Statistics Service.
Protein content has been climbing, too, with new yearly records being posted consecutively from 2016 to 2024. The 2024 milk marketing year finished with a 3.29% average protein content. This bookends a tremendous upward move considering protein levels stood at 3.04% in 2004, based on Federal Milk Marketing Order data.
Some people may question if the U.S. dairy industry can keep up with this historic pace of change on component production. This question is particularly important as overall U.S. milk production has stalled in recent years. Not only did U.S. milk output post its first back-to-back years of declining milk production since the 1960s at -0.04% and -0.23% respectively, 2022 milk growth was a meager 0.07%.
This situation makes growth in milk components even more critical, especially considering the generational investment in dairy processing with over $8 billion of new processing assets coming online through 2027. These record milk component levels are important as over 80% of the U.S. milk supply goes into manufactured dairy products, where product yields are driven by milk components, not fluid milk volume.
For deeper perspective, let’s turn our attention to pounds as that drives processing throughput.
From 2001 to 2010, milk, butterfat, and protein production all grew in a rather tight window ranging from 13.8% to 15.4% on a per-pound basis. That meant tracking milk composition from dairy farm patrons was a straightforward endeavor. Since then, growth rates for milk, butterfat, and protein production have decoupled. From 2011 to 2024, the following trends occurred in the U.S. milk supply:
- Milk production improved 15.9%
- Protein pounds climbed 23.6%
- Butterfat pounds vaulted 30.2%
Science brings opportunity
The game-changing story for the upward movement in components is genomics. Its predictive power comes from comparing an individual’s unique DNA sample to the overall population. This has become the dominant force in reshaping the composition of milk headed to dairy processing plants.
Momentum continues to build as genomic testing on dairy heifer calves is growing at an exponential rate. After being released in 2009, it took seven years to genotype the first 1 million dairy males and females. Then, it took two years to reach the 2 million threshold. As confidence in the system gradually grew, dairy farmers began running more tests with each successive year, further building momentum. By March 2021, the dairy industry moved past 5 million tests and raced by the 10 million mark in December 2024. Of those tests, 66% have been run on U.S. dairy cattle and the remaining 34% of tests are compiled from 72 countries around the world.
Prior to this heightened focus on genetics, factors such as improved nutrition and feeding programs, more digestible forages and grains, and enhancements in cow comfort set a moderate pace for improvements in milk, butterfat, and, to a lesser extent, protein production. Genetics, while playing a role, stood somewhat secondary to improvements taking place on the dairy farm. Once genomics were introduced, genetic selection for specific traits became the driving factor for improving milk, and more importantly, butterfat and protein yields.
Base change perspective
The first milk and butterfat recording took place in 1895. By 1936, USDA conducted the first genetic evaluation. At first, progress was slow. However, by 1965, it became apparent that genetic progress in dairy cattle had improved so much that it was time for a base change to have more equal comparisons between improvements of genetic traits over time. This base change or “rollback” on traits was first proposed to keep genetic evaluation numbers from appearing inflated or unrealistic. The larger the change, the larger the genetic gains that have been realized.
Subsequent base changes took place in 1974 and 1984. Beginning in 1989, base changes began occurring at roughly five-year intervals as genetic process gained momentum. Fast forward to the present and the April 2025 genetic evaluations marked the 11th such base change.
In scientific terms, the April 2025 base change means the genetic base is reset to reflect the typical cow born in 2020. That average cow becomes the zero for each trait. Any improvements over the next five years will move positively on the scale, whereas any reductions will present as negative value. For additional perspective, if the next genetic base change takes place in 2030, the base will reset to the average cow born in 2025.
Momentum builds
This April, Holsteins experienced the largest base change in its genetic history. Overall, Holsteins led all major dairy breeds by having a 45-pound rollback on butterfat. That was 87.5% higher than the 24-pound base change in 2020.
While not quite as large on a percentage basis, protein production rolled back 30 pounds in the April genetic evaluations. This was 1.67 times the improvement from 2020 when 18 pounds of protein were trimmed off U.S. genetic evaluations.
To fully appreciate how large this genetic base change has become in the genomic era, one simply needs to look back a few years. In 2015, the Holstein base rolled back 17 pounds for butterfat and a mere 15 pounds five years earlier in 2010. When it comes to protein, the shift was even smaller at 12 pounds and 14 pounds in 2015 and 2010, respectively.
The Jersey breed represents the next largest group of dairy cows. When combined with Holsteins, the two breeds and crosses among them comprise over 95% of the U.S. dairy cow population. Like Holsteins, Jerseys have made gains with a 20-pound base change for butterfat and a 15-pound roll back for protein in the April 2025 genetic evaluations.
To some extent, genetic progress did slow in Jerseys, as these base change numbers were down 20% and 25% for butterfat and protein, respectively, when compared to the previous base change. Back in 2020, Jerseys netted a 25-pound base change for butterfat, which was 1 pound higher than Holsteins. That same trend held for protein as Jerseys improved by 20 pounds compared to 18 for Holsteins . . . a 2-pound difference.
A positive outlook
Heritability estimates for butterfat and protein pounds range from 20% to 25% among peer-reviewed studies. Milk, stature, and body weight are the only other of the 49 traits presently reported for dairy cows with the same heritability range.
Therefore, genetic selection could very well push butterfat content to over 5% in the next decade if herd management — particularly nutrition — can keep up with genetics. This could be possible because in some parts of the world milk from water buffalo averages over 7% butterfat. Genetic selection and genomic testing will be driving butterfat and protein production for the foreseeable future.
