32 N. H. Agr. Expertmext Station [Bulletin 313 



New Hampshire, experiments are being carried on by C. A. Bottorff, 

 A. E. Tepper, R. C. Durgin and T. B. Charles at the poultry pathology 

 laboratories to combat it. Few conclusions have been reached yet, 

 but the work will be continued next year. {PnrneU Fund) 

 Rickets Not Caused by Chronic Coccidiosis 



Rickets in young chicks are not caused by chronic coccidiosis, as 

 was previously supposed, according to experiments made this last 

 year by C. L. Martin at the Poultry Pathology Laboratories. Work- 

 ing with four groups of chicks, four to six weeks old, he found that 

 I'ickets occurred first, followed by the chronic coccidiosis infection 

 instead of the other way around. {PurueU Fund) 



Fowl Pox Vaccine Distribution 



The total number of doses of fowl pox vaccine distributed to New 

 Hampshire poultrymen during the fiscal year 1937-1938 was 264.- 

 400, a decrease of 29,800 from the previous year. This work was in 

 charge of C. L. Martin. {Miscellaneous Income) 



Laryngotracheitis Vaccine Disposal 



During the season of 1937-1938, there were 65,400 doses of laryn- 

 gotracheitis vaccine distributed to poultrymen in New Hampshire, 

 as compared with 97,100 doses the previous year. The vaccine was 

 used on 12 farms in two counties as compared to 17 farms in five 

 counties the previous season. C. A. Bottorff is in charge of this 

 work. 



The distribution of this vaccine was carefully supervised and no 

 vaccine was allowed to be used except under the following condi- 

 tions: (1) Properly diagnosed outbreak; (2) where an outbreak 

 had occurred the previous year; (3) where a flock had been vacci- 

 nated the previous year; (4) where one flock or two closely adjoin- 

 ing flocks have been vaccinated due to an outbreak. {Miscellaneous 

 Income) 



Poultry Autopsies 



Poultry autopsies made by C. A. Bottorff and C. L. Martin at the 

 poultry pathology laboratories during the fiscal year numbered 

 1,762 and included 602 adult i)oultry, 1,097 chicks. 56 turkeys, 6 

 ducks and one grouse. 



Ruptured egg yolk was the leading trouble, being found in 24.2' . 

 of all adult birds examined. Other principal diseases in adults in- 

 cluded: coccidiosis, 20,7' < ; I'oundworms. 11.7' < ; leukemia. 7.8', : 

 ulcerated gizzard, 5.8/c ; internal hemoi-rhage, 5.6% ; tumors, 4.6' . ; 

 indigestion, 4.4/1 ; tapeworms, 3.9 '>( ; and coryza, 3.3% • 



The princii)al diseases of chicks were as follows: ulcerated giz- 

 zard, 31.5' ( ; puUorum, 12.6 ',r ; coccidiosis, 12.5 '/t ; epidemic tremors, 

 10% ; indigestion, 9.7'r ; pneumonia, 9.2'< ; navel infection. 8.:'', ; 

 and perosis, 2.6' < . {Miscellaurous Income) 



