During the year, as far as it has been possible, this department has endeavored 

 to follow the ideas as just noted, and as a result of this constant correlation of labora- 

 tory and field study, twenty-nine poultry plants in Massachusetts have been found 

 free from bacillary white diarrhoea. The hatchabihty of the eggs has greatly improved. 

 Previous to testing and before control measures were followed, by locating and elim- 

 inating disease carriers, all of these poultry plants suffered great losses. 



After a series of tests had indicated that there were no reactors in these twenty- 

 nme flocks, this department sought to find where eggs had been sold for hatching, 

 so that a record could be made of the value of the test as a means of producing disease- 

 free flocks from which clean stock could be procured. Data have been obtained by 

 personal visits and by correspondence. The reports thus far received have been most 

 striking. On one of the large farms where the breeding birds were infected with 

 Bad. pullorum, it had become almost impossible to rear even a small percentage of 

 the chicks hatched. Testing was begun in 1919, and the agglutination test revealed 

 27.5 per cent of the birds in the breeding pen infected. In 1920 another test was 

 run and the percentage of infection dropped to 20 per cent. The progeny of this 

 flock was tested in 1921 and only 6.5 per cent were found infected. During the present 

 season, 1922-1923, the breeding flock was found to be free from birds which could 

 be classed as carriers. This flock being established as a disease-free flock, records 

 were obtained from all persons receiving eggs for hatching from this flock. Results 

 were gratifying. From 1,110 tested breeding birds, 11,600 eggs were incubated and 

 8,700 chicks hatched, 92.9 per cent of which were reared. This is considerably better 

 than in 1919, when less than 15 per cent matured, the deaths in the first few days after 

 hatching being due to infection with Bacterium pidlorum. The accompanying plate 

 shows the livability of chicks furnished to other poultry plants from this disease- 

 free flock. 



HOC CHICKS. ' 

 »7» UVrNC ♦ _ 





'* » 





^ ^ }00 CHICKS r\ 



^ t'i'l. LIVING % ^ 



» » ' 



Plate I. — Livability of Chicks Furnished to Other Pjultry Plants from this Disease-Free Flock. 



