UNITED STATES DEPARTMENT OF AGRICULTURE 



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Contribution from the Bureau of Animal Industry 

 JOHN R. MOHLER, Chief 



Washington, D. C. 



April 23, 1921 



THE TURKEY AN IMPORTANT FACTOR IN THE 

 SPREAD OF GAPEWORMS. 1 



By B. H. Ransom, Chief, Zoological Division. 



CONTENTS. 



Page. 



Examination of market chickens 



and turkeys 1 



Experimental work 3 



Factors in the spread of gape- 

 worms 7 



Investigations on Maryland 



farms 8 



Page. 

 Significance of turkeys in relation 



to gapes formerly unrecognized — 10 

 Turkey the preferred host of the 



gapeworm 10 



How to avoid losses in chickens 11 



Conclusions 12 



List of references 13 



EXAMINATION OF MARKET CHICKENS AND TURKEYS. 



"POR THE PURPOSE of collecting some statistics on the preva- 

 lence of gapeworms {Syngamus trachealis) in the vicinity of 

 Washington, D. C, and of obtaining material for use in experiments, 

 examinations were made of the tracheas of 635 chickens killed for 

 sale at poultry stalls in Center Market during the latter half of 

 December, 1916, and the months of January and February, 1917. 

 Nothing definite is known as to the ages of these chickens except 

 that the chickens were all obviously large enough for food purposes. 

 Probably none were less than six months old, most of them likely 

 were older, and no doubt many were a year old or more. No gape- 

 worms were found. 



At the same time the tracheas of turkeys from the same market 

 were similarly examined. The ages of the turkeys, as in the case of 

 the chickens, were uncertain, but undoubtedly all the turkeys were 

 at least 6 months old, and many of them were probably more than a 

 year old. During the period mentioned the tracheas from 386 tur- 

 keys were examined. The next year, beginning March 2, 1918, an- 



1 The writer is greatly indebted to Dr. Lawrence Avery, of the Bureau of Animal In- 

 dustry, for assistance rendered in carrying out the investigations reported in this paper. 

 22888° — 21— Bull. 939 1 



