28 



A yearly increase in the number of flocks tested over the six-year period 

 is noted. With the exception of 1926-27, there has been a yearly increase 

 of non-reacting flocks from 1923-24 to the 1928-29 season. 



There were 145 flocks tested for the first time in 1928-29; 33 flocks, 

 tested previous to 1927-28, were again tested during the past season, 

 making 178 flocks which were not tested in 1927-28. Of the 321 flocks 

 tested in 1927-28, 235 were again tested in 1928-29, leaving 86 flocks 

 tested last season, which were not tested in 1928-29. Of these 86 flocks, 

 33 were without infection, of which 14 were 100 per cent tested. 



Of the 105 non-reacting flocks in 1927-28 which were tested again in 

 1928-29, 71 were 100 per cent tested during the previous season. Seven, 

 or 9.86 per cent of these, were infected at the 1928-29 test. Four of 

 the seven had less than 1 per cent infection, one had from 1 to 5 per 

 cent, and two above 15 per cent. The cause of the breaks in four of 

 these flocks was determined, and in each case could have been prevented 

 by proper management. In the other three, no history explaining the 

 breaks has been obtained. 



In the 34 flocks which were on the partial testing list in 1927-28 and 

 tested again in 1928-29, eight, or 23.52 per cent, were infected. Two of 

 the flocks had less than 1 per cent, two from 1 to 5 per cent, two from 

 6 to 10 per cent, and two from 11 to 15 per cent infection. 



Thus a total of 15 flocks which were non-reacting at the end of the 

 1927-28 season, were reacting in the 1928-29 season. In nine of these 

 flocks infection was introduced by means which has been definite!}^ traced. 

 Five of the six remaining flocks had less than 5 per cent infection. 



As long as poultrymen continue to disregard average disease jirevention 

 methods, and as long as there are infected flocks in the immediate neigh- 

 borhood of disease-free flocks, breaks are to be expected. Therefore, the 

 15 flocks recorded above as having had no infection in 1927-28, but be- 

 coming infected before the 1928-29 season, are not indications of lack 

 of progress. This is especially true in the case of the flocks which were 

 only partially tested the previous season. The fact that so many more 

 breaks occurred in that group is another reason for annual 100 per cent 

 flock testing. 



A study of Figure 4 will show that marked progress is being made in 

 eradication of pullorum disease in Massachusetts. There are thirteen 

 times as many birds in non-reacting flocks in the State as there were in 

 1923-24, while nearly four and a half times as many birds have been 

 tested. There were nearly four times as many birds in non-reacting flocks 

 in 1928-29 as in 1926-27, while only twice as many birds were tested. 

 Likewise there were nearly twice as many birds in non-reacting flocks, 

 and one and one-fourth times as many birds tested as in 1927-28. It will 

 also be noted by comparing the results recorded in Table VIII that the 

 percentage of total tests made in the non-reacting group is nearly double 

 that of 1926-27. 



A further indication that progress is being made is the increase in num- 

 ber of poultrymen testing their entire flock annually. Only when all 

 poultrymen realize this necessity, will the maximum progress be noted. 

 Table IX summarizes the progress that has been made by annual testing. 

 It will be noted that the average percentage of infection in the flocks 

 tested for the first time is over twice as great as that in the flocks tested 

 for three or more consecutive years, and nearly twice as great as that 



