FUNCTIONS OF NUTRIENTS 33 



animals doing work require only a small amount of 

 albuminoids, but a comparatively large amount of 

 carbohydrates. It is therefore obvious that carbo- 

 hydrates have the power of supplying energy to the 

 animal body to meet the waste of energy that is going 

 on during work. 



Fat may also be formed from carbohydrates when 

 they are fed in excess of the requirements for heat 

 and energy. Kellner points out that if animals are 

 fed with a ration poor in albuminoids and fat, but rich 

 in carbohydrates, the animals increase in body fat 

 at a rate which could not possibly have come from 

 the albuminoids and fat in the food, therefore some of 

 the fat must have been formed from the carbohydrates. 



The fat of milk may be derived from the carbo- 

 hydrates, for Professor Jordan (Geneva Experimental 

 Station, New York) had a cow fed for ninety-five days 

 on hay with maize and ground oats, wrfich had 

 previously been deprived of most of the fat by naphtha. 

 The cow gained in weight, and yielded 63 Ibs. of fat in 

 the milk. The food only contained 1 1 J Ibs. fat, of which 

 5-7 Ibs. was digested ; Hence most of the remaining 57-3 

 Ibs. fat must have been derived from the carbohydrates. 



Pat. The fat in the food supplies heat, energy, and 

 fat to the animal body. Although it is composed of the 

 same three elements, it has a greater value as a heat 

 producer than carbohydrates, owing to its containing 

 a very small proportion of oxygen in its composition 

 (molecule), and a comparatively large amount of carbon. 

 This means that much more oxygen will be required 

 to oxidise the carbon and hydrogen, i.e., more chemical 

 action will take place, and as a result more heat be 

 produced from a given weight of fat, than would be the 

 case from an equal weight of carbohydrates. 



C 



