Exploring Sustainable Dairy Nutrition with the help of NorFor – Interview with PhD Student Markos Managos

Markos Managos, PhD student at the Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences (SLU), will soon defend his thesis on how to design dairy cow diets with a lower environmental impact.

With a veterinary background from Aristotle University in Greece, Markos moved to Sweden in 2018 to study a Master’s degree in Animal Science. Since 2021, he has been working as a PhD student focusing on how feed ingredients influence greenhouse gas emissions from dairy production systems.

“I’ve always been interested in ruminant nutrition and the role of livestock in sustainable food systems,” says Markos. “This project allowed me to quantify and verify the environmental impact of different feeding strategies.”

Markos carried out feeding trials at Lantmännen research farm Viken, focusing on both dairy cows and pregnant heifers, along with LCA. One of the most striking findings from Markos’s work is that the scale of analysis matters.

“When we look at the cow level, we might see large effects of ration formulation on greenhouse gas emission. But when we zoom out to the farm or regional level, trade-offs emerge, and the reductions are often smaller than expected,” he explains.

These results highlight the complexity of agricultural systems and the importance of assessing interactions between animal performance, feed resources, and overall system emissions.

The research demonstrates that selecting feed ingredients with lower environmental footprints can reduce emissions at the system level.

“The feed ingredients I use are already available, tested, and safe,” says Markos. “This means they can be implemented in practice already today, after considering factors like cost and availability.”

While the project has not yet included a full economic assessment, Markos notes that diets based on by-products often appear cost-effective, though large-scale adoption could alter market dynamics.

“That is part of what makes the system so interesting, as small changes can lead to far-reaching consequences,” he adds.

Markos has made extensive use of NorFor throughout his PhD work.

“I used NorFor both as an educational and research tool,” he explains. “It helped design nutritionally balanced diets while minimizing environmental impact.”

By using the Swedish NorFor client software, he was able to simulate intake, energy balance, and emissions to plan feeding trials with dairy cows and heifers. He used NorFor Development Tool for post-trial calculations.

“It’s a great pedagogical tool for understanding the impact of feed composition and for simulating realistic experimental scenarios,” he says. “Having a feed evaluation model that reflects Nordic conditions and goes all the way down to net energy calculations gives more accurate assessments.”

After defending his PhD, Markos will continue his research journey as a postdoctoral researcher in the GigaCow project at SLU.

“It feels like a natural next step,” he says. “The goal is to use on-farm data or identify the data we’re missing, to apply what we’ve learned in my PhD on a larger scale.”

Markos Managos will defend his thesis “Feed Rations in Dairy Production and Their Climate Footprint - Linking Experimental Feed Trials with Life Cycle Assessment” at SLU on November 28, 2025, at 9.15 (CET) in Loftets hörsal at Ultuna. E-mail markos.managos@slu.se or mikaela.lindberg@slu.se if you want to attend online via Zoom.

Following the defence, there will be a seminar Sustainiability aspects on dairy diets | slu.se that also can be followed on-site and online.