154 



THE SCIENTIFIC FEEDING OF ANIMALS 



the feeding of work animals, therefore, the main problem is to furnish a 

 sufficient supply of nitrogen-free nutrients, while high protein content is 

 of minor importance. 



Zuntz and his co-workers have studied the problem of the consumption 

 of nutrients in different kinds of work and demonstrated that the dog 

 employed in draft work on a level course utilizes 29 per cent of the en- 

 tire energy expended, in useful performance, and 30.7 per cent in steep 

 up-grade work. Man utilizes 33 per cent, herbivora in horizontal motion 

 35 per cent and in horizontal draft 31.3 per cent. 



Zuntz, Lehmann and Hagemann determined the following valuations 

 for the horse: 



Energy consumed 



per 1 kg. of mass 



Rate of (animal + harness 



travel per -\- load, if any) 



minute for distance of one 



meter 



Motion on level course, no load, walking 78 meters 0.3256 calories 



Motion on level course, no load, walking 90 meters 0.3530 calories 



Motion on level course, no load, walking 96.3 meters 0.4346 calories 



Motion on level course, no load, trotting 176-205 meters 0.5478 calories 



Motion on level course 5 load of | walking 90 meters 0.3914 calories 



Motion on level course ( about 125 kg. } trotting 185.5 meters 0.6007 calories 



Energy consumed 

 in lifting 1 kg. of 

 mass to height of Efficiency 



1 meter 



Upgrade, without load, walking, grade 10.7° 6.8508 calories 34.3% 



Upgrade, without load, walking, grade 18.1°.... 6.9787 calories 33.7% 



Upgrade, without load, trotting, grade 10.7° 7.3647 calories 32.0% 



Energy consumed 

 in plain draft per- Efficiency 

 formance 



Draft performance, walking, grade 0.5° 7,143 calories 31.3% 



Draft performance, walking, grade 8.5° 10,235 calories 22.7% 



Draft performance, trot, level course 7,519 calories 31.3% 



Draft up hill (over exertion) 10,078 calories 23.0% 



Energy consumption and effciency are to no inconsiderable degree 

 affected by individuality, practice and fatigue. On the other hand, the 

 amount of energy consumed is not affected by the character of the nutri- 

 ents. Digested albumen, fat and digested carbohydrates may, after de- 

 duction of the work or energy required for mastication and digestion, 

 replace one another according to isodynamic values. 



3. Inorganic Nutrients 

 In addition to the organic nutrients, animals require a sufficient supply 

 of inorganic substances. These are absolutely necessary for the support 

 of life and the maintenance of health. Withdrawal of these substances 

 from the food causes disease and death. For instance, pigeons when de- 

 prived of the mineral matter in the food, but receiving an abundance of 

 albumen, fat and carbohydrates, will die in from 13 to 29 days (they 



