Testing Plan No. 1. — Tests on Birds One Year of Age or Older. 



A flock of hens is to be considered free from infection when reactors do not exist in the breed- 

 ing flock after the following plan has been carried out: — 



(a) First test at the age of one year or older. 



(b) Second test on non-reactors, six to twelve months later. 



By this plan, each adult in the breeding flock will have been tested twice. 



Testing Plan No. 2. — Tests on Pullets. 



A flock of pullets is to be considered free from infection when it is the product of a flock which 

 has already been tested twice, and when on test it contains no reactors. Three tests are thus 

 required, as follows: — 



(a) Original test when the birds are eight to twelve months old. 



(b) Non-reactors tested again six to twelve months later. 



(c) Third test made on the offspring of the birds already tested twice. 



Testing Plan No. 3. — Alternate Plan for Tests on Pullets. 



A flock of pullets is to be considered free from infection when produced as per the following 

 plan, and when, on the last of the following tests, no reactors are- found to exist. The procedure 

 is as follows : — 



(a) Original test when birds are eight to twelve months old. 



(b) Non-reactors tested again four to six weeks later. 



(c) Offspring of the above flock tested as pullets. 



(d) Non-reactors tested again four to six weeks later. 



In other words, the test is applied to pullets and their offspring. By this plan each bird is 

 tested twice before being bred. 



l<fQTE. — It is mutually understood that pullets are eligible for testing two months after the 

 flock has attained a 20 per cent egg production. Male birds may be used for breeders if tested 

 once and found non-reacting. 



Control Measures. 



A. All bleeding birds, male or female, to be leg-banded with bands furnished at cost by the 

 Department of Veterinary Science and Animal Pathology of the Massachusetts Agricultural 

 Experiment Station. 



B. All birds showing a positive agglutination reaction to be removed from the breeding 

 flock. Reacting birds to be disposed of if possible; but if it is found necessary to keep them as 

 egg producers, they are to be kept under strict quarantine. 



C. Male birds not to be housed during the breeding season with other than breeding stock. 



D. New stock brought on the place, whether adults, day-old chicks, or hatching eggs, to come 

 from stock shown to be free from bacillary white diarrhoea, as determined by the agglutination 

 test. 



jvjoTE. — The Department of Veterinary Science and Animal Pathology of the Massachusetts 

 Agricultural Experiment Station does not issue certificates of any kind or enter any agreement 

 to guarantee flocks. It will, however, co-operate with poultry associations or groups of poultrj'- 

 men who may wish to issue certificates of merit or accredit their own flocks. 



As with the health officer studying human disease, the poultry pathologist holds 

 a commanding position for observing the relation of disease to its control; the health 

 officer observing the relation of the public to the medical profession; and the poultry 

 pathologist the relation of the poultr;>aiien to the scientific workers. Our active 

 workers interested in this great epidemiological endeavor would unite the interests 

 and ultimate forces of both the poultrjanen and science in this great field of need for 

 service. 



During the present year the department has made 33,602 agglutination tests on 

 the blood of breeding birds in Massachusetts, which indicate in this State the wide 

 field for effort. This may represent one-third of the birds which should be tested and 

 does represent the urgent need. By the test a damaged mature breeding bird is 

 located, and by being eliminated from the breeding flock, the step to an impaired 

 day-old chick is intercepted. The expert in charge of a program for elimination of 

 bacillary white diarrhoea sees as a result of neglect to locate the infection a diseased 

 chickhood followed later by all the complications of the previous year. Finally, he 

 understands that when science has gained control to a sufficient degree over the dis- 

 ease conditions, then it is time for him to consider the larger opportunity for service, 

 — the service that relates not to a few poultrymen, but to the larger poultry hus- 

 bandry population which is seeking clean stock, be it breecUng hens, eggs for hatching, 

 or day-old chicks. 



