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PRINCIPLES OF FEEDING FARM ANIMALS 



work are as follows : dry substance, 20 pounds ; digestible 

 protein, 1.5 pounds; digestible carbohydrates, 9.5 pounds; 

 and digestible fat, 0.4 pounds. The ration should have a 

 nutritive ratio of 1 : 7.0. The first step is to calculate the 

 requirements of a 1200-pound horse, which are found to be 

 as follows: dry substance, 24 pounds; digestible protein, 

 1.8 pounds; digestible carbohydrates, 11.4 pounds; and 

 cUgestible fat, 0.5 pound. The second step is to assume a 

 trial ration which will meet approximately the requirements 

 as determined in the first step. From the amount of dry 

 substance required and from practical experience (see rule 

 5, page 109), one judges that a ration consisting of 12 pounds 

 of oats and 14 pounds of timothy hay will not be far amiss. 

 Calculating the dry substance and digestible nutrients of 

 this ration from Table 29 of the Appendix, the following 

 results are obtained : 



Comparing the nutrients of the trial ration with the re- 

 quirements of the standard, it is seen that the trial ration 

 is a little below the standard in dry substance and protein, 

 and a little above it in carbohydrates and fat. Thus the 

 third step is to modify the trial ration so that its nutrients 

 conform to the standard. Consequently, a feed which is 

 high in protein and low in carbohydrates should be sub- 



