THE COMPOUNDING OF RATIONS 369 



of a mash containing cottonseed meal and as a result were 

 slower in developing and coming into laying, where it fur- 

 nished the main source of protein, than when the protein 

 was furnished by the more palatable meat scraps. 



Grits are selected by fowls according to their attractiveness, 

 those which shine and sparkle most being the ones chosen. 



Nutritive Effect. — The nutritive effect of a feed or ration 

 must be considered as well as the amount of the various 

 digestive nutrients it contains. Linseed meal is a valuable 

 source of vegetable protein, but if fed in a greater proportion 

 than 10 per cent of the ration it is likely to be very laxative 

 in its effect, or to impart an undesirable greenish cast to 

 the color of the egg yolks. Winter rye offers a convenient 

 source of early spring greenness, but it must be fed with 

 caution at first, as it frequently causes digestive disorders. 



Musty grain or tainted meat is likely to cause difficulty 

 in the alimentary tract, which in young stock may be so 

 serious as to cause heavy mortality. 



Certain materials, as grit and charcoal, are not properly 

 feeds, as they are not fed for the purpose of furnishing any of 

 the nutrients. They are spoken of as feeds, however, because 

 they are commonly fed to bring about certain nutritive 

 effects. The function of the grit is to grind the feed, thereby 

 increasing its digestion coefficient, while charcoal acts as an 

 absorbent and as a corrective of intestinal disorders. 



One of the most important feed constituents in this con- 

 nection is crude fiber. While it has a very limited digestibility, 

 a certain proportion is necessary in the ration. Its function 

 is to dilute and open up the ration in the crop, gizzard, and 

 intestines so that the secretions in these respective organs 

 may have an opportunity to act. It serves to keep the intes- 

 tine properly distended and aids in preventing constipation. 

 If it was possible to feed fowls a ration that was wholly 

 digestible, they would very probably die of acute consti- 

 pation. 



Mart, Ilalpin and Steenbock' have secured very suggestive 

 results in feeding growing chicks in confinement on a synthetic 



' Journal of Biological Chemistry, vol. xliii. No. 2, 

 24 



