Serology is a method of detecting antibodies in an animal’s blood. These antibodies may be maternal antibodies, which come from the mother hen or they may come from vaccination. They are also found in the blood after an animal has experienced an infection. The presence of antibodies makes an animal immune to a particular disease.

Serological analysis and equipment needed
Our laboratory equipment allows us to detect antibodies to many diseases semi-automatically – however, some tests still need to be done by hand. For the analysis, the blood is placed on a matrix, to which the antibodies can bind. Then the blood is washed away, leaving the antibodies on the plate. A conjugate that binds to the antibodies is then added. It reacts with a dye to make the antibodies visible to our equipment. The concentration of antibodies is measured by the optical density of the solution and is also called “titer”.

Application in veterinary medicine
In addition to diagnostics and assessment of vaccination success, serology can be used in broiler production to determine the optimal time for vaccination against Gumboro disease. This study requires the examination of blood from day-old chicks. Maternal antibodies will be very high at the time the chicks are hatched, but the levels drop as the birds age. This makes them susceptible to the disease, but allows for effective vaccination at a certain age.

A formula is used to calculate the optimal vaccination time based on serum levels on day 1. At Poulpharm, 20,000 samples for PGVS (Personal Gumboro Vaccination Service) have been analyzed since August 2018. The optimal vaccination day depends on the vaccine used (Hot or intermediate vaccines).