ENEMIES AND DISEASES OF POULTRY 143 



The mating of one pair of fowls for the purpose of 

 producing male offspring fit for exhibition and another 

 pair for the production of female offspring fit for exhi- 

 bition is called double mating. This is practiced to a 

 great extent in the production of Barred Plymouth 

 Rocks, Brown Leghorns, partridge-colored fowls of all 

 breeds, and to scmie extent in producing fowls that have 

 penciling or lacing in their plumage. In double mating, 

 great care is taken to see that the male and the female 

 blood lines are kept separate, for if blood lines are 

 crossed, color will be injured. 



ENEMIES AND DISEASES OF 

 POULTRY 



ENEMIES 



GENERAL REMARKS 



A parasite is any creature that secures the whole or 

 part of its living from another. The parasites that 

 attack poultry are insects. 



Methods of Infestation by Parasites. Poultry become 

 infested with parasites in many ways, and it is advis- 

 able for the poultryman to keep a close watch to 

 prevent such infestation. Some of the most common 

 ways in which poultry becomes infested with parasites 

 are: (1) by the introduction of an infested fowl into a 

 flock; (2) by a hen infesting her chicks when they are 

 incubated or brooded in a natural way; (3) by allowing 

 infested fowls to roam at liberty; (4) by sparrows; (5) 

 by the parasites crawling up on roosts that are not 

 protected by safety appliances; (6) by the parasites 

 dropping on the fowls from the ceilings of houses; (7) 

 in nest boxes; (8) in dust baths. 



Effects of Parasites on Poultry. Parasites cause more 

 disease, ill health, and death among poultry than all 



