Distribution of Tests and Reactors 



As shown in Table 1,12 counties submitted a total of 284,848 samples to the 

 laboratory. The percentage of positive samples was 0.53. Norfolk, Middlesex, 

 and Worcester Counties had the largest number of tests. Two counties, Barns- 

 table and Suffolk, had no reactors among the tested birds. Four counties had less 

 than one-half of 1 per cent positive tests among the birds tested, while in only 

 one county (Bristol) were the total positive tests greater than 1 per cent. 



Value of Annual Testing 



Table 2 shows that 37 flocks were tested for the first time, representing 14,140 

 tests, of which 1.26 per cent were positive. In the intermittent group 21 flocks 

 were tested, which revealed 1.30 per cent positive tests. In both these groups 

 the percentages of positive tests are lower than those for the same groups in pre- 

 vious years. Although the number of birds represented is small, it appears that 

 the effect of continuous testing for 14 years in this State has expressed itself in 

 these two groups. The stock in some of these flocks is progeny of pullorum 

 disease-free breeding stock. 



Table 2. — Annu.al Testing Versus Single and Intermittent Testing 



Among the 26 flocks tested for two consecutive years, the percentage of positive 

 tests was 2.83. The fact that this percentage is higher than in any of the other 

 three groups is explained in part by one flock in this group which revealed 61.23 

 I)er cent reactors. 



It is encouraging to note that of the total number (262) of flocks tested, 178 

 have been tested for three or more consecutive years. Approximately 86 per 

 cent of the tests, of which 0.34 per cent were positive, represent flocks tested for 

 three or more consecutive years. Further, only 1 1 of the 1 78 flocks were classified 

 as infected, which points out that through aimual testing, supplemented by 

 effective preventive measures, flocks can be maintained free from pullorum dis- 

 ease. The maintenance of such a large nucleus of pullorum-free flocks will in 

 turn effectively establish a larger group of free flocks through properly controlled 



