386 FEEDS AND FEEDING 



Fourth, the ration should be so compounded that 

 the ratio between the protein and the carbohydrate 

 and fat shall be such as the investigations of scientists 

 have found to be the best for the purpose for which the 

 animal is fed. This ratio is called the nutritive ratio 

 and may be found for each class of animals, in the 

 Appendix. A ration so compounded is called a balanced 

 ration. 



Notes. The nutritive ratio best adapted to any animal or the 

 nutritive ratio for any feed is obtained by comparing the amount of 

 protein as given in the table with the amount of carbohydrates and fats, 

 after the fats have been changed to the carbohydrate basis by multiply- 

 ing them by 2i. 



One pound of cowpea silage is found to contain .015 pound protein, 

 .086 pound carbohydrate, and .009 pound fat. Now, if the weight of 

 fat is multiplied by 2.25, and added to .086, the weight of the carbo- 

 hydrate, the sum is .106. .106 divided by .015 = 7. There is 

 7 times as much carbohydrate as protein. This may be represented 

 in the form of a proportion as follows : 



carbohydrate and fat : protein : : I : 7. 



A wide nutritive ratio is one that has a large proportion of carbohy- 

 drates and fats compared with the protein. If the carbohydrates and 

 fats are more than 8 to I as compared with protein, the ratio is said to 

 be wide. If the ratio be less than 5.5 : i, it is said to be narrow. 

 A ratio between a wide and a narrow one is said to be a medium nutri- 

 tive ratio. 14 : I is a wide nutritive ratio, 7 : I is a medium ratio, 

 and 3:1 is a narrow ratio. 



From the table in the Appendix make a list of eight feeds that are 

 concentrates that have a narrow nutritive ratio. Make a similar list 

 of four forms of roughage that have a narrow nutritive ratio. From 

 the same table make a list of five feeds that have a wide nutritive ratio. 

 Make a similar list of six roughages that have a wide nutritive ratio. 



Note. For the dairy cow such a basis for feeding has been made 

 by Professor T. L. Haecker of the Minnesota Experiment Station. 



