MANHATTAN, Kan. -- Beef producers might get to say good-bye to the current antibiotics they use to deter liver abscess in cattle, and hello to a vaccine that is easier to use and could cost less.
For the past 12 years, T.G. Nagaraja, professor in diagnostic medicine and pathobiology at Kansas State University, has worked to develop the vaccine, which he said he hopes will be available by December 2001. Antibiotics have been available for about 20 years, but Nagaraja said there is concern about the use of antibiotics in cattle.
"There is increasing concern that the long-term use of antibiotics can lead to development of resistance in bacteria," he said. "Therefore, development of a vaccine would be an ideal method of control."
Nagaraja said cattle could receive the vaccine when they got other shots and that the vaccine's cost would be equal or less than the cost of antibiotics. He said keeping the cost low is important because there is no way to externally tell if cattle have abscessed livers, so every cow must be vaccinated.
Liver abscess is a problem exclusively with feedlot cattle, which are fed high-grain diets to achieve rapid fattening before slaughter. Grain produces acid in the cow's stomach lining, and if damaged, bacteria can flow through the blood stream into the liver, where the bacteria will start to grow.
Nagaraja said beef producers will continue feeding cattle high-grain diets, as meat from grain-fed cattle is more tender and juicy compared to cattle fed primarily all-grass diets. Also, grain-fed beef is less expensive for consumers.
About 5 million livers are condemned each year because of liver abscess. With livers selling at an average of $5 each, five million condemned livers means a $15 to $20 million loss to the beef industry. And that is if only the liver is condemned. Often, abscessed livers require trimming, and occasionally abscesses rupture causing the entire beef carcass to be condemned, contributing to a significant economic loss for the beef industry.
Nagaraja said economic loss occurs even before slaughter. Cattle with a liver abscess continue to eat high amounts of grain, but do not gain weight accordingly. Thus, a low feed conversion rate results in less income for beef producers.
Nagaraja said consumers should not worry about liver abscess because any liver with an abscess is condemned and not used for human consumption or pet food. "Even if the liver has a scar tissue where the abscess has healed, the liver is condemned," he said. "In terms of food safety there is no concern."