FEEDING STANDARDS— CALCULATING RATIONS 



103 



Ration for a work horse. — To illustrate the manner of using the 

 Modified Wolff-Lehmann standards, let us compute a ration for a 

 1,400-lb. horse doing medium work. The standard for horses at 

 medium work calls for 16.0-24.0 lbs. of dry matter, 1.4—1.7 lbs. digest- 

 ible crude protein, and 12.8-15.6 lbs. total digestible nutrients per 

 1,000 lbs. live weight. (See Appendix Table V.) The nutritive ratio 

 should not be wider than 1 :7.8-l :8.3. Multiplying the requirements 

 for 1,000 lbs. by 1.4, we find that this 1,400-lb. horse will require 

 22.4^33.6 lbs. dry matter, 2.0-2.4 lbs. digestible crude protein, and 

 17.9-21.8 lbs. total digestible nutrients. 



Let us suppose that this is to be a corn-belt ration and that dent 

 corn is the cheapest grain available. For roughage we have plenty of 

 timothy hay and good, bright, clover hay. According to the rule on 

 Page 88, horses at work should be given 2 to 3 lbs. of feed (roughages 

 and concentrates combined) daily per 100 lbs. live weight, with 10 to 

 18 lbs. of concentrates per head daily, depending on the severity of the 

 work. As it is costly to feed more grain than necessary, we take for a 

 trial ration 10 lbs. of corn and 18 lbs. of timothy hay, making 28 lbs. 

 in all, or 2 lbs. per 100 lbs. live weight. Computing the dry matter, 

 digestible crude protein, and total digestible nutrients in these allow- 

 ances, we have : 



This ration furnishes nearly as much total digestible nutrients as is 

 called for in the standard, but falls far short in crude protein, having 

 the very wide ratio of 1 :12.4. . We can bring the crude protein up to 

 the standard by substituting protein-rich concentrates for a consider- 

 able part of the corn, but this will add to the expense, for we have 

 assumed that corn is the cheapest grain available. Tho timothy hay is 

 more commonly fed to horses than any other in the northeastern United 

 States, good, bright, clover hay, which is rich in protein, is practically 

 as satisfactory for work horses. Let us then see how near we will 

 come to meeting the standard if we substitute clover hay for half the 

 timothy hay. Arranging the results as before, we will have : 



