34 POWER AND THE PLOW 



tions as to the cost of producing farm products on a group of 

 farms at Halstad, Minn., in the Red River Valley. Small grains 

 are the principal crop on these farms, which average 379 acres 

 in size, and conditions are quite similar to those where traction 

 engines are more extensively used. The results of six years of 

 investigation are published in Bulletin 73 of the above bureau. 



From data given therein we find that during the eight months 

 from April to November, inclusive, 135 horses worked an 

 average of 4.33 hours per week day, or a total of 906 hours. 

 For 104 working days, during the four inactive months, the 

 average was .77 hour per day. It is quite possible that these 

 horses, which averaged about 1200 pounds in weight, exerted 

 a full horsepower during every hour of work .in the plowing 

 season. On the other hand, during other seasons there was 

 much time while the horses were in harness that they were 

 exerting very little or no power, since the hours reported 

 included the entire time they were in the field. 



As a yearly average, from 1905 to 1907, each horse at Halstad 

 consumed 3.64 pounds of grain, and 6.55 pounds of hay for 

 each hour of work. The grain ration was made up largely of 

 corn, oats and barley, and the hay ration of timothy, wild 

 grasses, mixed hays, etc. Some pasturage and straw were 

 received in addition to the foregoing ration. 



According to Prof. H. P. Armsby, of Pennsylvania State 

 College, who is recognized as the foremost authority on animal 

 nutrition in America, the total heat values per pound of com- 

 mon feeding stuffs are as follows, the value in B.t.u. being 

 computed by the writer from the value in calories: 



TOTAL HEAT VALUE OP FEEDSTUFF8 



Calories B. t. u. 



Timothy hay 2045 8119 



Oat straw 2012 7988 



Clover hay 2025 8039 



Corn meal 2010 7980 



Oats 2125 8436 



Wheat bran 2065 8198 



Linseed meal 2314 9187 



