CONSECUTIVE, YEAR-TO-YEAR TESTING ESSENTIAL. 



The experience of the last five years has indicated that poultrymen requesting 

 service in bacillary white diarrhoea eUmination must test their breeding birds con- 

 secutively until no reactors are found in the breeding flocks. Many are of the opinion 

 that testing once will produce the magic which renders the flock free. This is usually 

 not the case. In one case where 1,172 breeding birds were tested in 1919-20, 3.6 per 

 cent were found to be infected. The following year 1,580 of the progeny were tested 

 and the infection was practically negligible. There was, however, sufficient infection 

 to classify this flock as not free from bacillary white diarrhoea. The following season, 

 1921-22, the flock was not tested to locate the last signs of the infection; instead 

 birds were bought in from the outside, and this 1922-23 season when the birds were 

 tested, instead of a disease-free flock the infection was greater than before testing was 

 started. This happens over and over again when close co-operation does not exist 

 between the scientific worker and the poultrymen. The length of time for the forma- 

 tion of the agglutinins varies with different birds; therefore, consecutive tests should 

 be run until there are positively no reactors, which indicate carriers or infected stock. 



The following comparative table, from data received this season, illustrates these 

 points : 



Table VII. — Consecutive versus Haphazard Testing. 

 I. Consecutive Testing Plan — Results Satisfactory. 



II. Non-consecutive Testing — - Results Unsatisfactory. 



Tested only three years as yet. 



