Dairy Digressions

A monthly podcast celebrating dairy science and featuring the leading thinkers in dairy production and foods.

Welcome to Dairy Digressions, the podcast from the American Dairy Science Association and the minds behind JDS Communications and the Journal of Dairy Science. Every other month, host Matt Lucy, PhD, an ADSA Fellow and former editor in chief of JDS Communications, explores the latest developments, fascinating discoveries, and breaking trends in the world of dairy science.

From pioneering technologies to innovative research, we cover a range of topics related to the dairy industry and go behind the scenes of the top labs and minds in dairy research. Our guests are leading experts in their fields, providing unique insights and perspectives on dairy career paths, research philosophies, and what excites them about the science of dairy production and dairy foods.

Whether you’re a dairy researcher, a student, dairy professional, or simply interested in learning more about the science behind the food we consume, Dairy Digressions is the show for you. Listen in as we dig deep into the science of dairy and discover what’s new and exciting in this ever-evolving field.

Episode Fourteen: Fostering Belonging in Our Community, Academia’s Gender Inequality, and Early Lactation Disease Markers with Jessica A. A. McArt, DVM, PhD, DABVP (Dairy Practice)

We don’t pick favorites among our guests, but we’re especially thrilled to welcome Jessica A. A. McArt, DVM, PhD, DABVP (Dairy Practice), to the pod! Jess is the new Editor in Chief of JDS Communications and associate professor of ambulatory and production medicine at Cornell University’s College of Veterinary Medicine, where her McArt Dairy Cow Lab focuses on improving cowside detection and the prevention of periparturient disease. Matt and Jess discuss her journey into dairy science—from growing up in Alaska to helming JDS Communications to wrestling with the shocking fact that only 14% of scientific journal editors are women and only 8% are editors in chief. The two discuss the very real systemic gender inequality in academia, its effects on a career in dairy science, and the role these forces play in the current shortage of large-animal veterinary practitioners. Looking to the future, Jess outlines her vision for JDS Communications and her challenge for our community to question assumptions and welcome diverse voices. Taking listeners into her research, Jess explains her recent findings on early lactation disease markers, including hyperketonemia and hypocalcemia–plus an explanation of dyscalcemia, a new term in the scientific milieu that originated in her lab. Finally, Jess leaves us with the best advice she received as a young researcher and the reasons she advises her students and mentees to say “yes” to opportunities—even if it pushes them outside of their comfort zone.  

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Episode Thirteen: Embryo-Mediated Gene Editing, Coat Color, and Mitigating Herd Heat Absorption in a Warming Climate with Goetz Laible, PhD

Join us for a special episode of Dairy Digressions recorded live at the International Embryo Technology Society’s 50th Annual Conference. Between sessions, host Matt Lucy sat down with Goetz Laible, PhD, biochemist and principal scientist at AgResearch and honorary associate professor at the University of Auckland in New Zealand. Their discussion walks listeners through Goetz’s work in developing and evaluating technologies for the genetic improvement of livestock. In the face of our warming climate, Goetz and his animal biotechnology team are working to advance gene-editing technology to help dairy herds cope better—and stay healthy and productive—with increasing heat exposure. The two also deep dive into the science behind Goetz’s recent work on light-colored coats in Holstein-Friesian cows. Using direct editing of embryos, Goetz and his team amplified naturally occurring coat mutation—which makes some cows lighter than others—to create lighter-colored cows in a single generation. These animals still retain their classic spots but with increased white coverage and a dilution of black spots to a light gray. Lighter gene-edited cows absorb a staggering 40% less solar radiation than their dominantly black counterparts, representing an important step forward for grass-fed dairy herds that spend most of their time outdoors. Listen in as Goetz sheds light on the potential applications of this technology in dairy herds, including his experience taking it to producers. He and Matt discuss the changing tides when it comes to farmer and consumer openness toward biotechnologies with the potential to help cows lead healthier, happier lives. An avid traveler, Goetz also shares his favorite perk of working in science and his advice for young scientists to embrace collaboration.

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Episode Twelve: Dairy’s Environmental Progress, Greenhouse Gas 101, and Key Outcomes from COP28 with Frank Mitloehner, PhD

Why does the dairy sector have such a good story to tell about environmental sustainability, and how can each of us be a better storyteller for the industry? Join us for a mega episode of Dairy Digressions to find out! Host Matt Lucy is joined by esteemed guest Frank Mitloehner, PhD, a professor and extension specialist in the Department of Animal Science at the University of California, Davis, and director of the UC Davis CLEAR Center. An agricultural engineer and air-quality expert, Frank explains exactly why today’s climate change is outside of normal climate patterns, outlines the three main gases responsible for the greenhouse gas effect (carbon dioxide, methane, and nitrous oxide), and illustrates how their increase leads to higher environmental temperatures. While we know that the energy sector, particularly carbon from fossil fuels, accounts for the majority of global emissions, agriculture and the methane from livestock play a critical role in moving the needle toward our shared net zero–emissions future. With a majority of American refrigerators containing animal-sourced foods, Frank is focused on how we can produce those foods while addressing environmental issues ranging from air quality and emissions to animal welfare, worker health and safety, and more. Using Frank’s home state of California as an example, the two discuss how agriculture is currently excelling in finding ways to turn methane from a liability into an asset; dairy farms are on track to achieve 40% or more methane reduction by 2030, reach climate neutrality, and sell credits to other sectors. Despite these incredible advancements, it can feel like the climate narrative around agriculture remains thorny. Frank explains why he established the CLEAR Center and his work—including a recent trip to speak at COP28—to not only advance the science around climate in agriculture but to break down misconceptions and help consumers and thought leaders better understand the importance of agriculture in sustainably nourishing the world.

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Episode Eleven: Heat Stress, Combating Embryonic Loss, and Tips for Running a Lab That Sparks the Principles—and Passion—for Lifelong Scientific Discovery with Pete Hansen, PhD

We're kicking off the new year—and our new season of Dairy Digressions—with a special guest, Pete Hansen, PhD, Distinguished Professor of Animal Sciences and L. E. “Red” Larson Professor at the University of Florida. Pete’s research focuses on embryo physiology and developing new management strategies for increasing dairy cattle fertility, particularly in the face of heat stress and a warming climate. A leader in embryology and early embryonic loss, Pete explains when embryos are most sensitive to heat stress and why—including the scientific tools we have for preventing these effects—from genetic selection to embryo transfer to management for cow health and the potential future of artificial embryos from stem cells. A longtime mentor to undergraduate and graduate students (don’t miss his paper on the topic!), Pete also lets listeners in on his teaching philosophy and shares tips for crafting a lab environment that fosters collaboration, hard work, and joy around science.

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Episode Ten: Stewardship Toward Healthier Cows, a Sustainable Climate, and Responsible Antibiotic Use with Daryl Nydam, DVM, PhD | cohosted by Kimmi Devaney of the Progressive Dairy Podcast

Join us for a very special episode of Dairy Digressions with our first-ever guest cohost, Kimmi Devaney of the Progressive Dairy Podcast and former ADSA Undergraduate Student Division president. Joining host Matt Lucy, the two sit down with Daryl Nydam, DVM, PhD, dairy health and production professor who serves as a director in Cornell’s College of Veterinary Medicine and the faculty director at the Cornell Atkinson Center for Sustainability. Daryl’s journey—from his childhood in a dairy and veterinary medicine family to a college student studying science while shooting hoops to working at the nexus of dairy, veterinary medicine, and human health—has been fascinating. Amidst growing consumer concerns about environmental and animal welfare issues, Daryl reassures listeners that cows today are thriving because of monumental advancements in veterinary care and management. The discussion covers the importance of optimal replacement decisions to reduce enteric methane production and ensure that each herd has the best cows in the barn. The trio also gets into another critical conservation issue: antimicrobial resistance. Daryl explains a novel, pathogen-based strategy for clinical mastitis treatment during lactation so farmers can make economical and stewardship-driven decisions, thereby reducing the need for antibiotics and hospital pen time. Listeners can also learn more about selective dry cow therapy: For some farms, gone are the days of treating every cow at dry off; now, with advanced diagnostics, we can treat only those cows with infections or at high risk of acquiring an infection during the dry period, maintaining milk quality and herd health without unnecessary antimicrobial exposure. Join us in this enlightening episode as we navigate the intricate landscape of dairy stewardship and why we should all feel optimistic about the dairy industry.

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Episode Nine: Behind the Scenes of Ireland’s Economic Breeding Index, the Complexity of Dairy Longevity, and Our Genetic Progress Towards Next Generation Herds with Donagh Berry, PhD

Pull up a seat as we dive into dairy genetics and Ireland’s esteemed national dairy breeding index—the Economic Breeding Index (EBI)—with the man who championed it, Donagh Berry, PhD. Berry is a quantitative geneticist and a Senior Principal Research Officer with Teagasc Animal & Grassland Research and Innovation Centre and Director of VistaMilk SFI Research Centre. He joins longtime friend Matt for a special installment of Dairy Digressions recorded during the ADSA Discover Conference on dairy cattle lifespan to explain how he became interested in animal genetics through a love of math and his work developing technologies and tools to help improve dairy farm profitability and futureproof dairy production for the next generation and beyond. Berry takes us behind the decisions that go into selecting traits for the EBI as well as the history of genetic selection—which up until 30 years ago focused mainly on milk production. The two discuss the state of dairy in Ireland and applaud the resilience and ability of Irish farmers to change and adapt over time, from adopting the EBI despite doubts to transitioning from seeing clover as a weed to a tool reducing dairy’s environmental footprint. Finally, Donagh walk us through the evolving discussion of dairy cow longevity as it relates to genetic progress, profitability, and dairy’s carbon footprint—including how genomics and sexed semen have turned the discussion on its head.

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Episode Eight: ADSA’s Graduate Student Division Award Winners on the Art of Scientific Presentations, the Power of Mentoring, and the Bright Future of Dairy

In the latest episode of Dairy Digressions, Matt welcomes a full house with the winners of ADSA’s Graduate Student Division awards. These young leaders are forging dairy’s future path—not just with groundbreaking scientific research but with their dedication, professionalism, and vision for where dairy is headed. Connor McCabe, current Graduate Student Division President, joins us to explain the division and what drew him to ADSA. Joining Connor are award winners representing both dairy foods and dairy production: Ursula Abou-Rjeileh, Richard Lobo, and Erica Kosmerl. Each pitches their winning research, which covers some of the most cited and popular work in the field today—from methane reduction to fatty acids in animal nutrition to alternative feeds and protein sources to interactions between dairy foods and human health. Matt chats with each guest about their expert strategies for a memorable presentation, their approaches to competitions, and tips for effectively communicating complex scientific concepts to any audience. They also explore the benefits of entering into a competition, including building confidence, communication skills, and comfort with feedback; gaining exposure to industry professionals and opportunities; and prepping for the rigors of a career in science. Finally, the group chats about the importance of mentoring and gives their best advice for surviving and thriving in graduate school. If you’re a dairy science student, hiring young dairy professionals, or teaching and mentoring students and young professionals, this episode is a must-listen!

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Episode Seven: Navigating Transition Cow Health and Accelerating Dairy’s Progress via Science and Medicine with Stephen LeBlanc, DVM, DVSc

Why is it such an incredibly exciting time in both dairy science and veterinary medicine? Find out as Matt sits down with Stephen LeBlanc, director of the prestigious Dairy at Guelph—a center that supports collaboration between dairy-related researchers—a member of the ADSA Board of Directors, and professor and research leadership chair at the University of Guelph. Stephen walks us through exactly what goes into a doctor of veterinary science (DVSc) degree and outlines his research to improve the prevention and treatment of reproductive disease in dairy herds, as well as his passion for bridging applied veterinary medicine with dairy science research. The two unpack the learnings from the joint reproduction, physiology, and endocrinology and ruminant nutrition symposium at the ADSA Annual Meeting, and wrestle with the hot topic of what is “normal” around dairy cow inflammation. Stephen gives Matt a rapid-fire round of the latest clinical recommendations and treatment protocols for uterine health issues frequently faced by dairy producers, including metritis and postpartum purulent vaginal discharge. Finally, don’t miss a boost of inspiration as Stephen explains why breaking down traditional barriers between dairy disciplines is accelerating our progress as an industry and making today the best time to be in dairy.

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Episode Six: Methane’s Genetic Heritability, Big Data, and the Changing Meaning of AI with Filippo Miglior, PhD

Are dairy cows second only to humans in terms of the amount of genetic testing they’ve received? Join in on the debate—and get an infusion of vibrant ADSA Annual Meeting energy—in episode six with Filippo Miglior, senior advisor of genetic strategic initiatives with Lactanet, dairy geneticist at the University of Guelph, and member of the 2023 Journal of Dairy Science Club 100. Filippo and Matt chat about the explosion of genetics data in dairy and how researchers are working with artificial intelligence to understand these metrics, then standardize and share them in order to help dairies become more profitable, efficient, and sustainable. Filippo unpacks an example of his team’s work on a genetic evaluation for milk-predicted methane in dairy cows. Using milk spectral data and an artificial neural network, they were able to isolate a trait to reduce methane without impacting fat, protein, and milk yield. This staggering scientific breakthrough, combined with nutrition strategies, could lead to a 50% reduction in dairy methane emissions by 2050—and save dairy producers millions of dollars in energy losses along the way. A prolific and decorated writer, Filippo also takes the time to give his best advice for getting a tough review and explains how essential reviewers are to the scientific process.

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Episode Five: Dairy Nutrition and Managing the Rumen Microbiome for Productivity and Sustainability with Jeff Firkins, PhD

Come for the dairy nutritionist banter—stay for the fascinating advancements in rumen microbiome science. In episode five, Matt sits down with Jeff Firkins, a dairy microbiologist and nutritionist at The Ohio State University and senior editor at the Journal of Dairy Science at the 2023 ADSA Annual Meeting. The two friends and colleagues reflect on lessons learned from the ruminant nutrition symposium on rumen microbiota—reviewing the forward leap dairy science has taken in understanding the thousands of microbial species in the rumen. Jeff explains his work on rumen fermentation and nutrient–rumen microbiota interactions, along with how he works directly with dairy farmers to think through nutrition challenges in their herds. Matt and Jeff dive into the state of dairy in Ohio and share their mutual respect for the incredible work dairymen perform in the field. Finally—just for you, listeners!—Jeff peers into his crystal ball and shares what he sees as the most promising approaches to improving cow efficiency and reducing methane production—from soil amendments like biochar to feed additives, improvements to forage quality, and more.

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Episode Four: The Dairy Reproduction Revolution of the Past and the Technology Breakthroughs of the Future with Paul Fricke, PhD

How is dairy technology similar to Star Trek? Beam in to find out as Matt interviews fellow reproductive physiologist and extension specialist Paul Fricke, PhD, from the University of Wisconsin–Madison and an editor at the Journal of Dairy Science. Paul chats through his lauded career to improve the reproductive efficiency of dairy cattle through research-driven, practical management strategies and new reproductive technologies applied on the farm. The two repro experts explain how getting cows pregnant is a hugely important piece of the profitability and productivity puzzle for dairy farmers, and benefits the health and longevity of dairy herds. Paul outlines what he calls the reproduction revolution—advancements in dairy fertility programs and management—that has taken place over the past few decades to dramatically improve pregnancy success in dairy herds, including the management steps for achieving an optimal high fertility cycle. The two then discuss where dairy reproduction is headed in the future, including the latest innovative approaches to the reproductive management of dairy cows. Will wearable devices, robotics, or needle-free pneumatic injection devices replace catching cows and giving shots—and help cows be cows? Tune in to learn more.

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Episode Three: Dairy Foods Microbiology, the Good and Bad of Bacteria, and Lessons from the Infant Formula Crisis with Olivia McAuliffe, PhD

Recording in person from the 2023 ADSA Annual Meeting, Matt steps out of his production comfort zone to chat about dairy microbiology with Olivia McAuliffe, a principal food scientist at Teagasc Food Research Center in Ireland, honorary professor at Queen’s University Belfast, and senior editor of the Journal of Dairy Science. Explaining her research in strain discovery, Olivia pulls back the curtains for listeners on the small army of dairy foods professionals working behind the scenes to optimize dairy microbiology, ensuring that dairy products are full of healthy and delicious microorganisms for fermentation and free of pathogens that might harm our health. Olivia outlines how she and the Teagasc Cultures, Fermentation, and Biotransformation team map the history of the bacteria used in fermented foods and discover novel starter cultures, pushing the industry toward new flavors and textures for the dairy products we know and love. The two also discuss the ADSA symposium on lessons learned from the 2022 US infant formula crisis, explaining the pathogen Cronobacter sakazakii and the advancements in dry sanitation and safety steps in the infant powder formula supply chain, including exciting new frontiers in bacteriophages—viruses deployed to act as natural predators to unhealthy bacteria, infesting and fighting them off in lieu of traditional antibiotics.

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Episode Two: Ruminant Methane, Sustainability, and the Future of Dairy in the Netherlands with Jan Dijkstra, PhD

In episode two of Dairy Digressions, Matt sits down with Jan Dijkstra, PhD, associate professor of ruminant nutrition at Wageningen University in the Netherlands, to talk about the topic on every dairy professional’s mind: the sustainable future of dairying. While this topic has taken center stage in the Netherlands—with the government’s plan to cut 50% of its current nitrogen emissions by 2030 to meet European Union climate targets—reducing greenhouse gasses is a global goal and a pressing research topic within the dairy science community worldwide. The two discuss the state of farming and the environment, tracing the link between human population growth to the growth of ruminants via a staggering recent analysis of global mammal biomass. Jan dives into the latest research on whether 3-nitrooxypropanol—an emerging feed additive—can effectively reduce methane production in dairy cows. Jan also shares his findings on the most effective strategies to mitigate ruminant methane emissions toward 2030 and 2050 climate goals. Listen in as they unpack the differences between dairy science research in the US versus the Netherlands and find out why Jan advises all students (especially those in science) to have a controversial attitude in their work.

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