13 



It is true that control measures advised in the past have nut stated deli- 

 iiitely that reactors should be disposed of by selling for meat purposes only, 

 l)ut it is doubtful if many farms are equipped to place birds in as strict a 

 cpiarantine area as is necessary to remove all danger of transmission of the 

 disease to disease-free birds kei)t on the premises. Several instances have 

 l)een called to our attention where reactors have been kept in the same house, 

 but in pens separate from non-reactors. In some cases it has even lieen nec- 

 essary to pass through the pen of reactors to carry feed to the non-reactors. 



It has been the experience of ])oultrymen who have tried both methods that 

 eradication is more quickly and economically accomplished if reactors are 

 sold to the market ratiier than kept for egg-producing purposes. Tlie sac- 

 rifice in the value of the eggs received from a flock of diseased birds will be 

 more than returned by the increased value received from non-reacting stock 

 ;it a later period. 



Age at which Pullets can be Tested 



For the past few years it has been considered necessary to withhold the 

 testing of pullets until they are in production, but no experimental data have 

 been collected to support this theory. Tlierefore, during the 1927-28 season, 

 such information as could be obtained on the sul:)ject of pullet testing has 

 been collected. Table VIII gives the sununary of the results in one flock 

 which was tested nearly a month before any of the pullets started to lay, and 

 each month thereafter for five montiis. Trapnest records on tlie flock were 

 available. 



Table VIII. Summary of Tests Made on a Trapnested Flock to Obtain Information on 

 the Proper Age to Test Pullets. 



There were 88 birds in the flock at the first test and 19 (21.59 per cent) 

 reacted to the original test. The flock was culled to 56 birds and when tested 

 the second time was in 10 per cent production. Two reactors were detected 

 at this time, one a female which had not started to lay, and the other a male. 

 Both birds were culled by a 1-25 dilution test; the female gave no reaction 

 in 1-50 dilution, while the male gave only a partial reaction in 1-50 dilution 

 of the blood serum-antigen mixture. Neither bird was autopsied. 



The flock was culled to 50 birds before the third test, at which time a 

 female gave a complete reaction in both 1-25 and 1-50 dilutions, and a male 

 gave a complete reaction in 1-25, but none in the 1-50 dilution. 

 The female was autopsied and Salmonella puUorum was isolated 

 from the ovary. This bird started laying November 20 and the test was 

 made on December 14. 



By the time the fourth test was made the flock had been culled to 37 



