Incubation 



1841 



After the eggs have been incubated far seven days they may be tested, 

 and those that contain dead germs or those that are infertile may be re- 

 moved. If several hens are set at the same time, the eggs from two hens 

 may often be placed under one hen after the undesirable eggs have been re- 

 moved. The other hens may then be set again, or may be placed in a special 

 coop for broody hens. 



Before the chicks are hatched, provision should be made for the hen 

 and her brood. When the chicks are twenty-four to thirty-six hours old 

 they may be removed from the nest and placed in coops provided for them. 



After the hen and the chicks have been removed to a coop, the nest should 

 be disinfected and the litter burned. • A liquid disinfectant is best for this 

 purpose, and it should be used with a spray pump. 





ARTIFICIAL INCUBATION 



The operation of the incubator is but one of the several factors deter- 

 mining the success of a hatch; yet it is possible, through carelessness or 

 neglect in such operation or through ignorance of the principles of incuba- 

 tion, to destroy completely the hatching power of strong and fertile eggs. 

 On the other hand, careful and intelligent operation may secure excellent 

 results from strong eggs and really 

 satisfactory^ results from weaker eggs. 

 By slightly changing his methods the 

 experienced operator is able to counter- 

 act, to some extent, the effect of 

 certain mistakes in operation. Success 

 in artificial incubation comes only 

 through a thorough understanding of 

 the factors discussed in this lesson. 



Incubators may be divided into 

 two classes: those heated by hot air, 

 and those heated by hot water. The former system is employed more 

 extensively in heating incubators ranging in capacity from sixty to six 

 hundred eggs. Incubators holding one thousand eggs or more are heated by 

 a hot- water system. There is little reason why either one of the means of 

 heating should have greater success in hatching eggs than the other, pro- 

 vided the same method of supplying heat to the eggs is used and other fac- 

 tors are equal. 



The most successful methods of supplying heat to the egg chamber of an 

 incubator are by diffusion and by radiation. There are incubators that 

 combine these two methods successfully, and others that use one or the 

 other method with good results. 



116 



Fig. 52. — Diffusion method. A, Hot-air 

 pipe; B, porous diaphragm; C, egg tray; 

 D, space between bottom boards for 

 ventilation 



