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History of Biological Control of Poultry Diseases in the U.S.A

Reflection on the control of poultry diseases in the United States brings to mind the extensive cooperative forces that were brought to bear to promote the growth of the poultry industry, which provides our nation with an inexpensive source of protein and aids in feeding people around the world. That cooperative spirit radiated from the Agricultural Experiment Stations at the land grant colleges, worked in close association with the U.S. Department of Agriculture, and it did not exclude the help and expertise of the commercial vaccineproducing laboratories. Poultry rearing became widespread in the United States in the latter part of the 19th century. Increased demand for chicks resulted in the development of artificial incubation of eggs and along with it the dissemination of a disease referred to as bacillary white diarrhea (BWD). The cause of the disease was discovered by Rettger (17) in 1899 and became classified as Salmonella pullorum, hence the name pullorum disease. The poultry men looked to the scientific personnel of the experiment stations to resolve the problem of the high chick mortality. It was discovered that this was an egg-transmitted infection, and the secret of its control was identification of the infected layers and elimination of such layers from the flock. The search for a biological test to identify the carrier birds in a flock was initiated at several experiment stations. The first major biological control for poultry diseases took the form of a tube agglutination test, developed by Jones (14) in 1913 for the detection of carriers of S. pullorum. This test set the stage for future developments.