Looking closer at fatty liver disease

Research dives deeper into subclinical challenges

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PLATTEVILLE, Wis. — While some diseases in cattle have obvious physical symptoms to help farmers diagnose them, fatty liver disease requires a look inside the cow to be able to accurately diagnose the syndrome. This creates a challenge when researching how to prevent and treat fatty livers. 

Ryan Pralle, research professor at the University of Wisconsin-Platteville, partnered with Andy Buttles, of Stone Front Farm near Lancaster, to conduct research on fatty liver disease as part of a research project funded by the Dairy Innovation Hub. The pair presented their findings at the Dairy Innovation Hub Summit Nov. 15 at UW-Platteville.

“Fatty liver syndrome is a common subclinical metabolic disorder in early-lactation dairy cows with the key part there being subclinical,” Pralle said. “We actually don’t have a very good idea on what the consequences are or how common it is because it’s really difficult to measure.”

Pralle drew on previous research that he conducted with Dr. Heather White during his early years at the university. They had used blood biomarker measurements to assess whether cows had relatively normal, healthy livers or instead had what is called high liver triglyceride as a proxy for fatty liver syndrome.

Pralle and the team conducted two blood tests — one at seven days in milk and one at 14 days in milk. Both showed 80% accuracy for diagnosing cows with high liver triglyceride, making it a practical solution on farms where cows could be surveyed as they calve in to determine whether or not they have high liver triglyceride levels/fatty liver syndrome.

The project collected data from 529 cows and followed them from their dry period through most of their lactation. The blood samples pulled from cows at seven and 14 days of milk were compared to the farm’s internal production records to ensure accuracy. The biomarker panels were run to predict high triglyceride level status in these fresh cows.

Pralle said there turned out to be a contrast between ketosis and fatty liver disease.

“For this blood biomarker panel, instead of diagnosing hyperketonemia, we’re predicting the actual liver triglycerides,” Pralle said. “That’s the main difference. … We are trying to dissect out what higher liver triglycerides means for the cow, not just ketosis.”

Preliminary results revealed that cows with fatty livers produced less milk and showed other health concerns such as ketosis, high blood fatty acids, loss of body weight and hypocalcemia. Pralle said he was surprised to find that nobody had looked at all of the factors side by side comprehensively.

“Cows that had cases of HTG generally had greater morbidity, more incidents of displaced abomasum, metritis and other illnesses than the healthy cows, so to speak, in this data set,” Pralle said. “We’re really pleased to see that it does seem that our blood panels are picking out cows that are going to have economically relevant adverse consequences that we want to manage against.”

Going ahead with their findings, the research team is now investigating things like value-added chemistry. In order to justify pulling blood samples on a regular basis, Pralle would like to syndicate with the monthly milk tests to achieve more data collection than simply liver health. He hopes to take the research further with more understanding of the transition cow index and keto monitors. 

Because there are not a lot of treatment options for fatty liver syndrome, Buttles said he focuses on prevention at his farm. He achieves this through nutrition.

“Our biggest strategy is the pre-fresh ration,” Buttles said. “In a perfect world, you don’t let them get too heavy, but in the real world, that happens sometimes.”

Buttles said that because fatty liver cows never reach their full potential, he believes it is important to conduct research like this to eventually find a treatment. 

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