so EXPERIMENT STATION BULLETIN 354 



covered. The remaining four l)ir(ls in this group showed typical Pullorum 

 lesions and Salmonella Pullorum was recovered from them. 



A. C. CoRBETT, F. E. Allen, E. F. Waller 



Anthelmentics in Poultry 



A numl)er of compounds were tested for their ability to remove the 

 common round worms of poultry. Two were found to be very effective 

 when given in the feed or in individual treatment in capsules. These were 

 zinc - nicotine - f^uorosilicate compounds supplied by General Chemical 

 Company, of New York, N. Y., and were identified as No. 405 and No. 

 603. No. 603 is a compound being used extensively as a plant dust in 

 aphid control. It was very effective in removing the large round worm 

 but the therapeutic dose and the toxic dose are too close to be safe. The 

 fluorosilicate was found to be the toxic principle. 



These compounds were also tried on sheep but were ineffective against 

 stomach worms. 



The compound No. 603 was found to be an excellent delousing agent 

 for birds, cattle, and pigs. When diluted with wetable sulphur it remained 

 on the skin of birds and cattle long enough not onlv to destrov the mature 

 lice but to kill the young as they hatched. 



E. F. Waller 



Contagious Indigestion (Bluecomb) 



During the spring and summer of 1943 we used the experimental 

 Bluecomb vaccine on five flocks totalling 17,000 birds. These farms had 

 all been infected for from one to five years. One third of the birds in these 

 flocks were inoculated and banded. It was previously observed that inocu- 

 lated birds would pass the virus in their feces for a time. With this in 

 mind all inoculated birds were placed on one side of the range, trusting that 

 there would not be too much mixing. Due to la1:)or conditions complete 

 segregation seemed impractical. By the time the birds were housed, inocu- 

 lated birds 'were present in all range shelters. Therefore, it is assumed that 

 all 17,000 birds were exposed to the virus. 



Three of the five flocks had no death loss from Bluecoml) disease. Sev- 

 eral birds were examined from the fourth flock during the summer and 

 fall and one hen in this group presented lesions grossly typical of Bluecomb. 

 It was not a vaccinated bird. In the fifth flock 13 birds in one shelter 

 sickened with typical symptoms of this disease complex. Five of them 

 died and from one of the sick birds the Bluecomb virus was again isolated. 

 The disease did not spread to the other birds in this shelter or to any of 

 the other approximately 1600 inoculated pullets on this range. 



Winter laboratory w'ork was limited to blood studies of inoculated 

 birds, to tissue studies of infected birds, and to the imi^rovement of vaccine 

 production. It was found that if the freshly harvested Chorio-allantoic 

 membranes were quickly frozen at 0°F for 15 minutes, they dried more 

 rapidly and could be ground quicker and finer. 



The field work for 1944 is being carried on with a larger number of 

 birds and on more farms. All young birds on the farms are being inocu- 



