Cornell scientists have developed the first vaccines that can prevent metritis infection in dairy cows.
Metritis develops after a cow gives birth, when bacteria take advantage of the open vagina and cervix to settle in the uterus. Infected cows exhibit signs of fever, pain, inflammation, lack of appetite, depression and reduced reproductive abilities.
Metritis affects as many as 25% of the roughly 9 million dairy cows in the United States, costing nearly $400 per case in lost productivity and treatment costs, a statement from Cornell said.
Promise for limiting antibiotics?
The new vaccines can prevent the disease from taking hold and reduce symptoms when it does. According to Rodrigo Bicalho, assistant professor of dairy production medicine at the College of Veterinary Medicine, metritis is the number one cause of systemic antibiotic use – and the vaccines could help limit that use.
"Our lab has been developing a vaccine for years now based on our research of this disease," said Bicalho. "We created multivalent vaccines, complex cocktails with several components we've identified as important to causing metritis."
Bicalho and his lab researchers tested five combinations of various ingredients and delivered three subcutaneously via a shot and two intravaginally. All three subcutaneous vaccines were effective, significantly reducing incidence of disease by up to 83%.
Cows that were vaccinated with the subcutaneous vaccines had lower incidence of postpartum fever and puerperal metritis, shorter disease periods and improved reproductive performance compared to those that did not receive the vaccines.
"The powerful protection these vaccines produced surprised us. We expected some protective effect but nothing as strong as what we found," said Bicalho. "An effective vaccine against uterine diseases will have a significant positive impact on the dairy industry, limiting the use of antibiotics, and decreasing economic losses due to these disorders.
Bicalho says the next step is to simplify the complex vaccines we created by identifying which components are the most important and removing the rest.