Dr. T.G. Nagaraja: Challenges of Liver Abscesses | Ep. 32
Jul 5, 2023
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Dr. T.G. Nagaraja, an expert on liver abscesses in cattle, provides insights into the causes, impacts, and ongoing research on the condition. He discusses the challenges of developing a 100% effective vaccine and its potential connection to reducing foot rot. The importance of collaboration and research in cattle nutrition is also highlighted.
Liver abscesses in cattle have significant economic impacts on animal performance and carcass yield, resulting in lower profitability for the feedlot and beef industry.
Understanding the microbiology and virulence factors of Fusobacterium necrophorum is crucial for developing effective interventions to prevent liver abscesses.
Deep dives
Impacts of Liver Abscesses on Animal Performance and Carcass Yield
Liver abscesses in cattle have significant economic impacts on animal performance and carcass yield. Cattle with liver abscesses eat less, gain less weight, and have reduced feed efficiency, resulting in lower profitability for the feedlot and beef industry. Furthermore, the presence of liver abscesses can lead to adhesions to surrounding organs and tissues, which requires additional trimming during carcass processing, reducing carcass yield. Additionally, the quality of the beef can be negatively affected, further impacting economic returns. Overall, liver abscesses are a major concern in the beef industry due to their detrimental effects on animal performance and economic viability.
Microbiology and Virulence Factors of Fusobacterium necrophorum
Fusobacterium necrophorum is a primary causative agent of liver abscesses in cattle. This anaerobic bacterium plays a beneficial role in the rumen by fermenting lactic acid and digesting proteins. However, under certain conditions, it can cross the rumen wall, reach the liver, and cause abscesses. The bacterium produces leukotoxin, a protein exotoxin that can kill white blood cells, which helps it evade the immune system and establish an infection. Fusobacterium necrophorum exists in different biotypes, with one biotype, known as subspecies macrophorum or biotype A, being the main causative agent of liver abscesses. Understanding the microbiology and virulence factors of this bacterium is crucial for developing effective interventions to prevent liver abscesses.
Research Focus: Hindgut and Beef-on-Dairy Cattle
Current research in liver abscesses is exploring the potential role of the hindgut and its impact on the development of liver abscesses. The hindgut of cattle, similar to the rumen, plays a significant role in fermentation and digestion. Acidosis and subsequent ruminitis in the hindgut could be predisposing factors for liver abscesses. Researchers are investigating the occurrence of fusobacterium necrophorum in the hindgut and its potential as a source for liver infection. Additionally, studies indicate that only certain cattle harbor the subspecies or biotype of fusobacterium that causes liver abscesses. Further research is needed to understand why some cattle have this subspecies, which could provide insights into liver abscess prevalence in different animal populations.
The Future: Vaccine Development and Collaboration
The development of an effective vaccine against fusobacterium necrophorum remains a primary goal for preventing liver abscesses. A successful vaccine would provide a viable alternative to antibiotics commonly used for liver abscess control. Collaboration and interdisciplinary research are essential for advancing the understanding of liver abscesses. Earl Bartling, a mentor to the speaker, exemplified the importance of collaboration in research. The speaker emphasizes the significance of collaborative efforts in bringing together experts from diverse fields such as veterinary medicine, grain science, and statistics to drive innovative solutions for liver abscess prevention and control.
Liver abscesses significantly affect animal performance, reducing their feed intake, weight gain, and carcass yield. In this episode, Dr. T.G. Nagaraja, an expert on the field, goes into the subject and sheds light on the intricate world of liver abscesses in cattle. He provides valuable insights into the causes and impacts of this condition, as well as ongoing research on it. Also, Dr. Nagaraja talks about his commitment to developing a 100% effective vaccine regardless of the challenges posed by the complexity of the problem.
โThe only time when we detect lower abscesses is when the animals get slaughtered in the slaughterhouse.โ - Dr. T.G. Nagaraja.
What you'll learn:
(00:00) Highlight
(02:11) Introduction
(08:39) Dr. Nagaraja's first steps in the field of liver abscesses
(12:06) The importance of liver abscesses
(19:37) Important discoveries
(26:21) The creation of a vaccine
(28:43) Dr. Nagaraja's studies and experience on the prevalence of liver abscesses
(40:23) Foot rot and its relationship with treatments to liver abscesses
(48:51) Future discoveries
(55:20) The final questions
Meet the guest: Dr. T.G. Nagaraja
Experience
Current: Distinguished University Professor of Microbiology at Kansas State University
Background
Ph.D., Microbiology
M.Vsc., Veterinary Microbiology (Mysore Veterinary College, University of Agricultural Sciences, Bangalore, India)
B.VSc., Bachelor of Veterinary Science (Mysore Veterinary College, University of Agricultural Sciences, Bangalore, India)