Researchers Race Against the Clock to Discover Preventive Measures for Liver Abscesses in Cattle
By: Maribel Alonso
Email: Maribel.Alonso@usda.gov
Researchers at the USDA’s Agricultural Research Service (ARS) are looking to help the U.S. food industry save millions annually by reducing liver abscess formations in cattle.
The prevalence of liver abscess formations in cattle continues to raise concerns among dairy and beef producers. This problem also remains a challenge for researchers, as the primary factors driving formations are not yet fully understood.
Reducing liver abscess formation is even more critical in calves born from dairy cows mated with beef sires (“dairy-beef crossbred cattle”). These crossbred calves are becoming a greater percentage of the total beef population in the beef industry and are also shown to be more susceptible to this problem [close to 50% vs 20% for traditionally raised beef cattle].
Cattle with liver abscesses don’t show clinical signs and are generally identified too late –at harvest. The economic losses associated with this condition in cattle is in the millions.
Rand Broadway, a research microbiologist with the USDA ARS’ Livestock Issues Research Unit (LIRU) and researchers at Texas Tech University, Kansas State University, and West Texas A&M University, has studied the relationship between liver abscess formation in dairy-beef crossbred cattle for the past 5years in relation to diet type, ruminal acidosis (caused by high grain diet), and the bacteria community in the digestive system.
The researchers have made significant progress in isolating the primary drivers contributing to this problem through a series of breakthroughs, with their latest study disproving the long-held belief that acidosis and high energy diet intake are the sole cause for the development of liver abscesses.
“We confirmed that acidosis and aggressive grain feeding is not the only driver of liver abscess development, and our research indicates that pathogen presence alone is sufficient to cause an abscess,” said Broadway. “Therefore, if we can reduce the pathogen load and block its pathway to the liver, we can control the problem.”
Scientists are focusing next on identifying which bacterial pathogens are causing liver abscess formation, and where these bacteria can be found. Species of Fusobacterium and Salmonella bacteria were detected in the abscesses studied in the laboratory at LIRU. Since these bacteria can be found in the cattle environments, they can reach the animal’s liver if they gain access to the circulatory system through lacerations in any part of the animal’s digestive system.
Animals are particularly more vulnerable under some types of stress. This could be due to weather [heat/cold] stress, gastrointestinal disruptions, illnesses, or the presence of other pathogens that cause inflammation of the gastrointestinal tract. Management during weaning and relocation, most calves are shipped to new locations after weaning, may also trigger these conditions.
This study reveals that the nutritional management alone plays a less critical role in liver abscesses formations than previously believed. This insight helps producers make more informed decisions about diet management practices focusing on efficiency. Additionally, it allows researchers to redirect their efforts toward understanding the pathogens involved and the pathway(s) they use to enter the animal’s body [and get to the liver]. This shift in focus has become increasingly important for researchers and time is of the essence for producers, as every minute incurs costs.
The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in U.S. agricultural research results in $20 of economic impact.
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