256 SCIENTIFIC FEEDING OF ANIMALS 



tolerable condition are fattened, there is no notice- 

 able increase in the amount of flesh, but principally 

 large quantities of body fat are formed. As the 

 proteins in the food do not take part in the con- 

 version of the nitrogen-free food constituents (fat-h 

 carbohydrates) into body fat (p. 79), there is no 

 reason why animals during fattening should be 

 given much protein matter. It might be con- 

 cluded from this that in a fattening ration no 

 more protein was necessary than in a maintenance 

 ration, a view which, however, is not correct. The 

 large rations which are given during fattening cause 

 a heavy drain upon the glands which secrete the 

 protein-containing digestive juices. If only 0.6 Ib. 

 digestible protein per 1000 Ibs. live weight were 

 given to animals which were being fattened, a 

 large portion of the non-nitrogenous nutrients in 

 the ration would not be digested. For the proper 

 utilisation of the food, not more than 8-10 parts 

 of digestible nitrogen -free material ought to 

 be given with each part of digestible protein, 

 as was mentioned on page 39. If it is possible to 

 obtain a supply of cheap food rich in protein, 

 the nutritive ratio (p. 231) may with advantage 

 be narrowed down to as low as 1-4. To give more 

 nitrogenous material than this would, for the reasons 

 already given (p. 62), be a mistake, and in practice 

 ought never to be done. 



In fattening grown animals there is thus a con- 



