ENVIRONMENTAL CONDITIONS 369 



It can then be stored away for use another year. This practice 

 is very satisfactory with early-hatched Leghorn chicks. 



Factors Affecting Growth. — There are many factors affecting 

 the growth, development, and maturity of chickens. All of these 

 logically fall under the one head, Environmental Conditions. 



Environment Constantly Effective. — Environment, which is a 

 word used to mean all of the conditions surrounding the individual, 

 is a factor which is constantly acting for the good or for bad. As 

 the surroundings tend toward bringing about the desired results 

 in environmental conditions, rapid growth is attained from the 

 very beginning. The growth which a chick makes is determined, 

 in part, by the vigor and vitality of the parent stock, and the condi- 

 tion of the parent stock, also, in turn, is largely influenced by the 

 surroundings to which they were subjected. Again, the vigor of 



Fig. 170. — Growing poultry on free range is the most satisfactory method. Gasoline-heated 

 brooders are used on this farm. (Photo by Cornell University.) 



the germ in the fertile egg is influenced by the conditions under 

 which the eggs were kept previous to hatching, and the develop- 

 ment of the embryo is entirely determined by the surroundings 

 to which the egg is subjected during the hatching process, such, for 

 example, as variations in temperature, the degree of moisture, the 

 amount of turning and cooling, and the general care of the incu- 

 bator. At hatching time, differences in size and weight of chicks 

 are in direct proportion to the humidity in the incubator, which 

 directly affects the evaporation. 



During the brooding period, the factors of environment are 

 also of paramount consideration, feed and temperature being the 

 controlling ones. It should be the aim of every poultry keeper 

 to constantly study his birds, and, by careful selection and elimi- 

 nation, keep fewer but better birds. This is especially important 

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