The NMR glossary provides brief definitions and explanations of terms and jargon used on our site.



Infectious Bovine Rhinotracheitis


An animal has immunity to a disease when it is protected either by antibodies to that disease or by cell mediated immunity. It may have made these antibodies itself in response to infection or vaccination or acquired them passively in colostrum or antiserum. Cell mediated immunity can be acquired through some vaccines (although not necessarily all vaccines), or from infection


The animal’s ability to mount an immune response to an infection may be interfered with by drugs, nutritional deficiencies or concurrent infections, for example BVD virus

Incubation Period

The time from when an animal is first infected with an organism until symptoms develop. For most diseases this is a few days but for encephalopies and Johnes disease for example the incubation period can be years

Infectious Disease

A disease caused by the entrance into the body of organisms (as bacteria, protozoans, fungi, or viruses) which grow and multiply there