73 



Subtracting 1,590 grams (3.505 pounds) from 6,374 grams (14.054 

 pounds) gives 4,784 grams (10.549 pounds), the total available nutri- 

 ents which must be supplied by the oats. Dividing this sum by 491, 

 the total available nutrients in a kilogram (2.2 pounds) of oats, gives 

 9.74 kilograms (21.43 pounds) as the amount required. This quantity 

 of oats would require the expenditure of 1,208 grams (2.660 pounds) 

 nutrients for the labor of digestion (9.74 kilograms X 0.124 = 1.208 

 kilograms) (2.660 pounds). The total expenditure of nutrients which 

 the ration necessitates for the labor of digestion would therefore be 

 2,502 grams (5.514 pounds) (1,294 grams+1,208 grams = 2,502 grams) 

 (2.854 pounds+2.660 pounds = 5.514 pounds). This exceeds by some 

 400 grams (0.882 pound), the value which is thought most desirable 

 for the normal maintenance ration, i. e., 2,100 grams (4.630 pounds). 

 The expenditure of this amount of nutrients for the work of digestion 

 is thought desirable, because it would liberate the amount of heat which. 

 Zuntz calculates is required for maintaining the body temperature. 



The ration may be adjusted on a more reasonable basis by diminish- 

 ing the straw to 0.3 kilogram (0.66 pound) and the oats to 9.46 kilo- 

 grams (20.812 pounds). The total quantity would be the same as 

 before, and the amount required for the labor of digestion would be 

 practically equal to that which is considered most desirable. The 

 ration as adjusted would be as follows: 



Table 13. — Calculated ration for farm horse at vork. 



This ration is, according to Zuntz, more satisfactory on economic 

 grounds, since it does not contain an excess of material which must be 

 wastefully assimilated. The fact is also pointed out that it might not 

 prove satisfactory otherwise, since it contains a small amount of 

 coarse fodder. The other examples given by Zuntz are more com- 

 plicated. 



SUMMARY. 



Some of the principal deductions noted in this bulletin follow: 

 Horses, like other animals, require a definite amount of nutrients 

 and energ}^ per 1,000 pounds live weight for maintenance, and an 

 extra amount, chiefly energj^-yielding nutrients, for muscular work, 

 the amount being proportional to the character and amount of work 

 performed. 



17QQQ M^ 10; 



_nQ 



