26 N. H. Agri. Experiment Station [Bulletin 284 



Due to these five outbreaks, flocks in the immediate vicinity were vacci- 

 nated as a precaution. 



There were eleven farms that vaccinated approximately 31,000 birds 

 as a preventative. In all cases there was a good take and no adverse results 

 were noted from the vaccination. (C. A. Bottorff cnid C. L. Martin — State 

 Fund.) 



Testing for Bang's Abortion Disease 



The greater amount of testing for Bang's Abortion Disease by the stand- 

 ard tube agglutination blood test was made from blood sent in by practicing 

 veterinarians. There were 3,346 samples tested from herds in New Hamp- 

 shire, as compared to 2,615 samples last year. The percentage of infection 

 this year was 8.9% as compared to 14.41% last year. This is probably due 

 to retests of many herds where the reactors had been removed since the 

 previous year. 



Out of state samples tested, numbered 1,210 as against 835 the previous 

 year. These showed an infection of 18%. 



At the present time Federal testing is being carried on whereby an in- 

 demnity is being paid for slaughtered reactors at a maximum of $20 per 

 head for grade cattle and $50 per head for purebreds. The work was started 

 in October and this laboratory is recognized as the official testing laboratory 

 for New Hampshire. 



By replacing reactors to Bang's Abortion Disease tests with heifers 

 which have been raised free from the disease, five or six herds which have 

 been studied have shown a constant decrease in infected members. The sixth 

 group, where no isolation of reactors was practiced, has shown an infection 

 increase from 7 positives, 3 suspicious and 6 negatives to 10 positives, 1 

 suspicious, and 4 negatives. During this time many reactors have been re- 

 moved, but the wave of infection continued. 



The project will be continued to determine how long it will take to elimi- 

 nate all reactors from these herds, by practicing this method of testing along 

 with proper isolation and segregation. A check will also be made to deter- 

 mine how long clean herds will remain clean under practical conditions. 

 (C. L. Martin — PurneU Fund.) 



PuUorum Testing 



During the past fiscal year 209,754 samples from 206,443 birds were 

 tested for Pullorum. There were 29,643 fewer samples than for the previ- 

 ous season, but only 5,920 fewer birds tested because of less retesting. The 

 total number of adult birds tested is still more than one fifth of the total 

 number of adult birds in the State of New Hani])sliire, and of tliese l)irds 

 tested 99.83% were found to be free from Pullorum. 



There were 146 flocks containing 175,650 birds that had been tested 

 100% for two or more consecutive years and no reactors found. There were 

 25 flocks containing 10,926 birds that were tested 100% for the first time 

 and no reactors found. There were 22 flocks in which only part of the total 

 birds were tested and all of the 10,472 birds tested were negative. 



