402 THE FEEDING OF ANIMALS 



first shoots of grasses and clovers, should be fed in the 

 fresh condition. After the birds approach maturity and 

 growth is slower, so that a much larger proportion of the 

 food is used for maintenance, and during colder weather 

 when the heat from the extra energy required for diges- 

 tion is useful, more of the coarse foods can be fed with- 

 out apparent disadvantage. 



492. Incidental effects of the food with laying hens. 

 Another reason, sometimes a very important one, for 

 using such foods as young clover, fresh or dried, is the 

 effect on the color of the egg yolk. Eggs from hens which 

 are fed only certain grain and animal substances gener- 

 ally have yolks of a pale yellow color. This is often 

 objected to by those who have a preference for eggs with 

 darker orange-colored yolks. The liberal feeding of fresh 

 or dried young clover, alfalfa, or grass will generally 

 insure the deeper coloration. The cause for this frequent 

 lack of what may be considered the normal yellow color 

 of the egg yolk is not well known, but the occurrence of 

 the pale color can be generally prevented by attention 

 to the food. 



At the New York Experiment Station, pens of hens 

 which were fed alike except that no hay or green food 

 was given to one, while three others had different amounts 

 apportioned by geometrical ratio, of clover hay alter- 

 nated with green alfalfa, produced eggs showing marked 

 differences in color. The orange-yellow shade of the 

 yolk corresponded directly in intensity with the propor- 

 tion of hay or green fodder in the ration. The greenish 

 color of the white also varied but not so regularly. Eggs 

 from each lot were very uniform in appearance. 



The differences in flavor and other qualities which 

 are probably caused by the food cannot be satisfactorily 



