204 Diseases of Poultry 



tinguish the 32 species of parasites or to know their life 

 histories in order to keep his plant free from them. It is 

 only necessary to know that some of them stay on the birds 

 and can only be exterminated by treating the birds, while 

 others spend most of their time on the under sides of the 

 roosts in cracks and can best be exterminated by contact 

 sprays containing cresol or kerosene. A single application 

 is not efficient in either case but treatment must be repeated 

 2 or 3 times at intervals of a few days to destroy those that 

 hatch after the treatment or are concealed beyond its reach. 

 A routine procedure by which a poultry plant can be kept free 

 from parasites is very useful. The following method has 

 proven very successful at the Maine Experiment Station. 



All hatching and rearing of chickens is done in incubators 

 and brooders. The growing chickens are never allowed to 

 come into any contact whatever with old hens. Therefore, 

 when the pullets are ready to go into the laying houses in 

 the fall they are free from lice. Sometime in the later 

 summer, usually in August or early in September, the lay- 

 ing houses are given a thorough cleaning. They are first 

 scraped, scoured and washed out with water thrown on the 

 walls and floor with as much pressure as possible from a hose. 

 They are then given two thorough sprayings, with an inter- 

 val of several days intervening, with a solution of cresol 

 such as is described in Chapter II. Then the roosting boards, 

 nests, floors and walls to a height of about 5 feet are thor- 

 oughly sprayed with the lice paint (kerosene oil and crude 

 carbolic acid described on page 15). 



For ridding the birds of lice the Maine Station formerly 

 recommended dusting two or three times at intervals of 

 several days to a week with the lice powder described on 

 page 211. All birds which were to be kept over for the next 

 year's work were treated in this manner before they were 

 put into the cleaned houses, 



