EXERCISE 88 

 COMPUTING A STANDARD RATION 1 



Statement. A ration which supplies nutrients in proper amounts as well as in proper proportions is 

 called a standard ration. 



Object. To learn how to compound a standard ration for different classes of farm animals using, 

 as far as possible, the common feeds of the farm. 



Materials. Paper; pencil; table of feeding standards. See Table II of Appendix. 



Directions. Compute a standard ration for pigs weighing from 50 to 75 pounds each, and assume 

 that one feed most convenient to use is corn. Pigs of this age require 45 to 52 pounds of dry matter, 

 6.3 pounds of digestible protein, 32.96 pounds of digestible carbohydrates, and a nutritive ratio of 

 1 : 5.2 daily per 1000 pounds of live weight of animal. The table of feeding standards is designed to 

 show the pounds of each nutrient required for 1000 pounds of animal. When the feeds for 1000 pounds 

 of weight are determined, the amount required for the animal or animals under consideration may be 

 readily computed. 



Using corn alone the ration would contain 67.8 pounds of digestible carbohydrates and 4.6 pounds 

 of fat in 100 pounds. Multiplying the fat by 2.25 and adding it to the carbohydrates gives 78.2 

 pounds of carbohydrates in 100 pounds of corn. Therefore, to furnish 32.96 pounds of carbohydrates 

 would require 42.15 pounds of corn. This amount of corn contains only 3.16 pounds digestible protein, 

 which is too small an amount. The nutritive ration of corn, 1 : 10.4, is entirely too wide. 



1. Instead of feeding corn alone, make the ration of corn 20 pounds and wheat middlings 20 pounds 

 daily per 1000 pounds of live weight. Compute the pounds of dry matter, protein, and carbohydrates 

 contained in this ration and compare with the standard. 



2. Assume that the ration consists of corn 27 pounds and skim milk 87 pounds per 1000 pounds. 

 live weight. Calculate the pounds of dry matter, digestible protein, and digestible carbohydrates 

 supplied and the nutritive ratio of the ration. Compare this with the standard. 



3. In a similar manner compute a standard ration for pigs of this age, using corn, wheat middlings, 

 and meat-meal or tankage. Place all figures in the blank on the following page. 



4. Compute a standard ration for growing yearling steers, using corn silage and wheat straw 

 as the basis, and purchasing cottonseed meal. Compute a standard ration for fattening two-year- 

 old steers with corn, sorghum silage, and alfalfa hay as the basis, and the privilege of purchasing 

 cottonseed cake or old process linseed meal. Make up a ration for fattening steers with corn stover, 

 oat straw, cowpea hay, and cottonseed meal as the basis. 



Questions. How does the local farm practice compare with the feeding standards ? Are the farmers 

 using too much or too little protein ? How may the farmers of the community secure additional protein 

 without purchasing it? Which is the more costly to buy in feedstuffs, protein or carbohydrates? 

 How many farmers are feeding their pigs on corn alone or on corn and pasture grass ? Which class of 

 animals requires the greater quantity of protein or the narrower rations, growing or grown animals, 

 working or idle horses, milking or dry cows, laying or barren hens ? What is the effect of an ample supply 

 of protein on the quantity and luster of the hair coat of animals ? Which shed or molt the earlier, those 

 which are liberally or those which are sparsely supplied with protein ? 



References. Henry and Morrison. Feeds and Feeding Abridged, pp. 423-433. The Henry Morrison 

 Company. Plumb, C. S. Beginnings in Animal Husbandry, pp. 281-287. Webb Publishing Company. 

 Jordan, W. H. The Feeding of Animals, pp. 280-295. The Macmillan Company. 



1 In farm practice it is frequently advisable to depart somewhat from the accepted feeding standard. For example, when 

 feeds rich in protein are high priced and those rich in carbohydrates, like com, are cheap, it will pay to feed a wider ration than 

 the standard prescribes. The successful feeder, however, conforms as nearly to these standards as the cost of his feed and the 

 value of the products will allow. 



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