382 The Feeding of Animals 



approach maturity and growth is slower, so that a 

 much larger proportion of the food is used for main- 

 tenance, and during colder weather, when the heat 

 from the extra energy required for digestion is useful, 

 more of the coarse foods can be fed without apparent 

 disadvantage. 



Incidental effects of the food. Another reason, some- 

 times 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 generally 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 in- 

 sure 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 alternated with green alfalfa, produced eggs show- 

 ing marked differences in color. The orange -yellow 

 shade of the yolk corresponded directly in intensity with 

 the proportion 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, 



