CLEAR Conversations: Genetics could offer a lasting tool for reducing livestock methane
Reducing methane emissions from livestock will likely require more than a single intervention. Feed additives, manure management, vaccines, improved measurement and other strategies all have a role to play. But genetics offers something that many other approaches do not: the potential for methane reductions to accumulate over generations.
That was the message from Emily Melchior, manager of Global Outcomes Research at Zoetis, during the 2026 State of the Science Summit: Reducing Methane from Animal Agriculture at UC Davis when she sat down to chat with CLEAR Conversations host Tracy Sellers.
Melchior, who specializes in ruminant microbiology, nutrition and vaccination strategies in cattle production systems, participated in a panel focused on the development and adoption of low-methane genetics. She said genetic selection should be viewed as one tool among many available to producers — one that can potentially provide lasting benefits while maintaining the traits that make an animal productive and profitable.
“Genetics provides one of many interventions that can be applied, but the nice thing about it is it is a cumulative and fairly permanent effect,” Melchior said. “It can be just one of many tools that a producer can use if they're trying to integrate production and health of the animal and sustainability work.”
Making methane part of the breeding equation
Unlike an intervention such as a feed additive, which is administered directly to an animal, genetic selection works over generations.
That difference can make genetics more difficult to communicate, Melchior said. The impact isn't necessarily something producers can see immediately. But it also creates an opportunity to incorporate methane reduction into decisions producers are already making about the animals they want in their herds. The goal, she said, is not to select for lower methane at the expense of production or animal health.
“Production matters,” Melchior said.
For a genetic strategy to be useful to producers, animals still need to perform. Dairy cattle need to produce milk consistently, maintain health and reproductive performance, and remain productive members of the herd. That means methane reduction needs to be considered alongside the traits that contribute to a farm's overall profitability.
Zoetis has incorporated that approach into its Dairy Wellness Profit (DWP$) index, a selection index designed to place relative value on traits important to dairy producers. The 2026 version of the index incorporates additional sustainability considerations while continuing to emphasize production, health and other economically important traits.
The approach reflects a broader principle in livestock sustainability: A lower-methane animal still needs to be a productive animal.
“Ultimately, the index that Zoetis has developed is a whole-animal index,” Melchior said. “It, of course, emphasizes production and quality production, but there's many other things that are part of that. And animal health and animal well-being are really integrated into that index.”
A cumulative approach to methane reduction
One of the potential advantages of genetic selection is its cumulative nature. When a desirable genetic trait is passed from one generation to the next, its benefits can continue to build within a herd over time. That makes genetic selection fundamentally different from interventions that must be administered repeatedly throughout an animal's life. For methane reduction, researchers are investigating the extent to which differences in methane emissions among animals can be measured, inherited and incorporated into breeding decisions.
Melchior said growing interest in genomic indices could give producers additional precision when making those decisions.
“There’s a lot of opportunity for producers to make meaningful change using genetics and genomic indices,” she said.
The approach could become increasingly important as producers face multiple pressures — from productivity and profitability to animal health and environmental stewardship. Rather than treating sustainability as a separate objective, genetic selection provides a way to incorporate it into the broader breeding strategy.
Balancing sustainability and profitability
One misconception about sustainable livestock production, Melchior said, may be that producers have to choose between environmental performance and productivity. But with a selection index, producers can consider multiple traits simultaneously and identify animals that offer the best overall fit for their production system.
“With this index, they have the opportunity to maybe target or select for one trait without finding a balance in how that affects other productive measures or other sustainability measurements,” Melchior said. “But ultimately, this is trying to help that producer find the balance between milk production and overall profitability for their operation while incorporating some sustainability traits.”
That balance will become increasingly important as companies and producers look for ways to meet sustainability goals without compromising the economic viability of livestock operations.
Genetics is one tool in a larger toolbox
Melchior emphasized that genetics should not be viewed as a replacement for other methane-reduction strategies. Instead, it can complement them. A producer could potentially combine genetic selection with feed strategies, improved animal management, manure management and other interventions as technologies continue to develop.
“The nice thing about it is it is a cumulative and fairly permanent effect that can be just one of many tools that a producer can use,” Melchior said.
That makes genetics particularly interesting as the livestock industry moves toward a more integrated approach to methane reduction — one that considers the animal, the farm and the entire production system.
Looking ahead
Melchior expects genetics to play an increasingly important role in livestock sustainability over the next decade. Interest in sustainable genetics is growing among researchers, producers and companies, she said, while advances in genomic technology are creating opportunities for greater precision in genetic selection.
“The more interest you have in it to really refine and give more precision to genetics and genetic progress, it's just going to lift everyone,” she said.
For Melchior, one of the most encouraging developments is the diversity of researchers and organizations now working on the challenge.
The State of the Science Summit once again brought together scientists from multiple disciplines and countries, providing an opportunity to exchange findings and consider how different approaches might work together.
“It's a wonderful opportunity to be here because there's such a breadth of incredible science being conducted globally,” Melchior said. “Coming to a meeting with so many shared opportunities to share and expand on your horizons, it's just wonderful.”