REPOET OF AN INVESTIGATION AS TO CAUSE 



OF DEATH OF CHICKS IN SHELL IN 



ARTIFICIAL INCUBATION 



By H. B. Arbuckle 



In the State of North Carolina it is estimated that over five million 

 eggs are hatched annually in incubators. Of this number, accord- 

 ing to figures presented in this paper, over two million eggs, with per- 

 fectly developed chicks in them are thrown away each year. 



At the prevailing price of market eggs this winter this represents 

 a loss of $80,000 in money. When we consider the time, the inter- 

 ference of business, and the high cost of breeding stock, a large per 

 cent of which is brought about by artificial incubation, we are justified 

 in placing the loss at double the figure given. This loss for the United 

 States approaches the astounding figure of $3,000,000. 



The author has been interested in poultry raising for over thirty 

 years, and it was his unsatisfactory experience with incubators that 

 led to this investigation, which covers a period of five years. 



When it was discovered that the most serious loss in artificial incu- 

 bation was due to death in the shell after the eighteenth day, provided 

 the conditions generally believed to be essential to a good hatch be kept 

 under proper control, the confines of the problem were greatly re- 

 duced. 



The loss in artificial incubation was first attributed to unequal tem- 

 perature. Incubation was conducted at temperatures ranging from 

 one hundred degrees to one hundred and six degrees with slightly 

 varying results in losses. Finally, the temperature factor was re- 

 moved by using a mercury regulator, which kept the temperature 

 within a quarter of a degree of the desired standard throughout the 

 incubation period. 



It was next thought to be due to abnormal evaporation on account 

 of incorrect moisture. Ex])eriinents led to a very satisfactory de- 

 tci'iiiiiiatioii of piMqx'v moisture. A lieu was })]aeed on a sitting of 



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