Mastering Mastitis
by Sarah Haines
quick home test to help producers and veterinarians decide the course of mastitis treatment for their cows is being evaluated by U of G researchers.
Clinical mastitis -- a condition characterized by an inflammation of the udder and decreased milk production -- has burdened dairy producers for decades. University of Guelph researchers at the Elora and Ponsonby Dairy Research Stations are responding to this costly disease, by evaluating a new HyMast Culture System, to help producers diagnose mastitis on-site.
"This on-site test will allow producers and their veterinarians to determine the necessary treatment for mastitis in a cost-effective and timely fashion," says Dr. Jocelyn Jansen, a doctor of veterinary science candidate in the Department of Population Medicine.
The need for continued support of this research is clear. At least one in every five dairy cows experiences a case of mastitis during lactation. Significant losses include discarded milk, lost production, premature culling, increased labour, costs of veterinary services and decreased genetic gain.
Mastitis is traditionally treated with antibiotics, but it's suspected these drugs may result in increased antibiotic residues in milk. Recently, it has been suggested there may be a link between antibiotic use in agriculture and increased antibiotic resistant bacteria implicated in human disease. So, the public is demanding the more targeted use of antibiotics in livestock.
The new HyMast test system -- a simple milk vile which has a paddle embedded with two different types of growth media (gram positive and negative organisms)-- can determine whether antibiotic treatment is necessary for cows suffering from mastitis.
Just take a milk sample, incubate it, and results will be ready within 24 hours. This system, which determines the bacterial agent associated with clinical mastitis, acts as a decision-making tool. If there is growth on the gram positive side of the paddle -- signifying Staphylococci and Streptococci bacteria -- antibiotics are recommended. But if there is either no growth on the paddle, or growth on the gram negative side -- meaning the presence of coliforms -- antibiotics are considered ineffective.
The study of this technology began last fall. It involves about 26 herds, including 200 cows from the Elora and Ponsonby Dairy Research Stations, and should be completed in the spring of '98. Milk producers value Elora and Ponsonby for their rich tradition of research and dynamic atmosphere, where university and industry meet to solve problems and create solutions that help keep Ontario producers so competitive.
The HyMast test, which was developed in Israel, has been on the market in North America since last fall. But its economic and biological potential has yet to be realized. Jansen, who is working with population medicine professors Ken Leslie and David Kelton, is optimistic about this new technology.
"Alternative treatments must be recognized and adopted to maximize efficiency for the dairy industry," she says. "With the development of the HyMast Test as an effective aid for decision-making, a rational therapy-targeting approach shows great promise."
