382 MANUAL OF CATTLE-FEEOIlSra. 



units of heat, an amount producible by tlie coinbn&tion of 

 0.57 poundb of material of the composition of btareh. 



FurtLennore, a poa'tion of this water in converted into 

 vapor, thus caobing a still greater demand for heat, hi 

 Ilenneberg's experiments on sheep (page 235), about one- 

 half the water drunk was excreted as vapor. If we as- 

 sume that this proportion is applicable to cattle, and that 

 of the 59 pounds of water about 30 pounds are converted 

 into vapor, it is easy to calculate from the data on page 

 234 that the production of sufficient heat for this purpose 

 would require the combustion of 4.44 pounds of organic 

 matter of the composition of starch. 



If, now, we add to the digestible non-nitrogenous mat- 

 ters of the meal rati(m the amounts estimated to be sav(Ml 

 by tlie less consumption of water, we obtain the following 

 residt : 



Present; in the corn meal 3.41 pounds. 



Warming 59 lbs. of water to temperature of body 57 ** 

 Evaporating BO lbs. of water 4.4^4 ** 



Total,. 8.42 " 



Feeding standard 8. 40 ** 



Adding to this the fact that an increased conBumption of 

 water augments the protein consumption in the body, we 

 have a plausible explanation of the sufficiency of the ap- 

 parently insigniHcant ration of three quarts of tneaL 



Essentially the same result was reached by Salmon (loe>> 

 oit\ though from different data. These calculations, of 

 course, are based on somewhat uncertain assumptions re* 

 garding the amount of water drunk and the proportion of 

 it which is Evaporated, and therefore make no claim 

 to accuracy. The only object of introducing them Imm 

 is to show that it is not at all impossible that exclu- 

 sive meal feeding can maintain an animal The px-aetica- 



