PRAIRIE FARMER'S POULTRY BOOK 



This is the way to handle chicks for profit 



Selecting Eggs for Incubation 



If pedigree hatching is pursued, eggs from a given hen or 

 a given mating are numbered and only those used with the 

 sitting hen or the pedigree tray, as the case may be. Eggs 

 that should not be set comprise those that are unusually large 

 or small, uneven in shape, round eggs, elongated eggs, stale 

 eggs, dirty eggs, thin-shelled, rough-shelled or mottled eggs, 

 and eggs with low specific gravity. Eggs that may safely be 

 set are those that are ovate in shape with smooth and even 

 texture and of high specific gravity. Specific gravity may be 

 determined by the magic tester, or by weighing with the hand, 

 or by noting the size of the air cell with the lamp tester. If 

 cell is large the specific gravity will be low. 



Changes in Incubation 



During the process of incubation the air cell gradually in- 

 creases in size, so that when the chick is ready to be hatched 

 the air cell occupies about one-third of the shell. The yellow 

 yolk is not all used but is retained in the egg to be at the last 

 absorbed into the abdomen of the chick to provide nourish- 



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