ANIMAL DRAFT POWER 



133 



different treatment from oxen because they have smaller 

 stomachs. As they have less power to digest foods, they must 

 be fed less at one time and at more frequent intervals. 



The degree of digestibility is dependent on two factors; 

 namely, the length of time the food remains in the digestive 

 tract,^ and on the fineness of the division of the food. Mastica- 

 tion is less in horses and mules than in oxen because the former 

 must do all the chewing before the food is swallowed while 

 ruminants, such as the ox, regurgitate their food and chew it 

 at will. 



German students of animal nutrition, among them Wolff and 

 Lehmann, have prepared tables showing the amount of chemical 

 constituents required for animals of a standard weight of 1000 

 pounds, performing a given kind of labor. Other weights are in 

 proportion. These tables are known as feeding standards and 

 are an approximate statement of the amounts of the different 

 nutrients required by animals. They serve as a guide for 

 feeders. 



WOLFF-LEHMANN FEEDING STANDARDS 1 



[Showing amounts of nutrients per looo pounds live weight for one day's feeding.' 



Oxen:- 



At rest in stall. . . 



At light work. . . . 



At medium work. 



At heavy work. . . 

 Horses: 



At light work. . . . 



At medium work. 



At heavy work . . . 



Calories. < 



16,600 

 22,500 

 27,200 



32,755 



22,150 

 26,700 

 32,750 



1 From The Feeding of Farm Animals, by E. W. Allen. Farmers' Bulletin No. 22, U. S. Depart- 

 ment of Agriculture, Washington, D. C, 1901, p. 12. 



2 For an unworked ox of 1000 pounds weight the standard calls for 0.78 pound of digestible pro- 

 tein, 8 pounds of digestible carbohydrates, and o.i pound of digestible fat, which would furnish 

 :6,6oo calories of heat and energy. When heavily worked the same ox would require, according to 

 the standard, food with four times as much protein and of nearly twice the fuel value. 



3 The value of food to produce heat for the body and energy for work is measured in calories and 

 is calculated from the nutrients digested. The fuel value of one pound of digestible fat is estimated 

 to be 4230 calories and of one pound of digestible protein or of carbohydrates about i860 calories. 

 The total value of a feeding stuff is found by using these factors, the equivalents for the common 

 foods being given on pages 134 and 135. 



* A calorie is the amount of heat required to raise the temperature of one pound of water about 4 

 degrees. 



1 Cattle are said to retain their food from three to eight days, while horses retain 

 it four days or less. 



