54 



FARMER'S CYCLOPEDIA OF LIVE STOCK 



protein a much smaller quantity of pro- 

 tein is required for the vital functions, 

 and that the gain in flesh may extend 

 over a longer period than when protein 

 is fed alone. 



Armsby illustrates this in the case of 

 a dog that, when fed on lean meat, re- 

 quired 1500 grams to maintain himself 

 in good condition. When fed only 500 

 grams the dog lost flesh and was starv- 

 ing. "When, however, 200 grams of fat 

 was fed with the 500 grams of lean meat 

 the dog not only kept in good condition, 

 but actually gained in weight. The an- 

 imal was actually better nourished on 

 500 grams of protein and 200 grams of 

 fat than on 1500 grams of protein. 

 The use of the 200 grams of fat saved 

 1000 grams of protein. It is probable 

 that had the dog been able to have eaten 

 the 200 grams of fat in addition to the 

 1500 grams of protein he would not have 



The best proportions of protein, fat 

 and carbohydrates to feed different ani- 

 mals at different stages of growth, for 

 the different purposes of growth, fatten- 

 ing, work, milk, egg and wool produc- 

 tion have been studied very extensively 

 and have been formulated into feeding 

 standards which will be taken up and 

 discussed farther along in this acccount. 



In summing up this phase of the ques- 

 tion it may be said that animals can live 

 and form flesh on protein alone. But 

 by the addition of carbohydrates or fat 

 to the ration they can live and form 

 flesh for a longer period on a much small- 

 er quantity of protein. Lean meat is 

 formed entirely from the protein sup- 

 plied in the food. In the next section 

 we will see how fat is formed. 



PRODUCTION OF FAT 



Lean meat is made from the protein 



Fig. 35 — HARVESTING SILAGE CORN OX A PENNSYLVANIA FARM 



made any better gain than when fed 

 simply the 500 grams of protein. The 

 excess protein would simply have been 

 consumed in the body and excreted with- 

 out tbe production of any additional 

 flesh, in other words, would have been 

 fed at a loss. 



The carbohydrates appear to be 

 equally as efficient as the fats in pro- 

 tecting protein from consumption in the 

 body. This is a matter of considerable 

 importance since nearly all the feeding 

 stuffs grown on the farm are much 

 richer in carbohydrates than in fat. 



The question now arises if fats and 

 carbohydrates protect protein from con- 

 sumption to what extent may they be 

 supplied in the ration? May the ration 

 consist almost entirely of fats and car- 

 bohydrates or must the greater part be 

 made up of protein? 



in the food. Can fat also be produced 

 from protein? Dogs exhausted of fat 

 by starvation have been fed on lean meat 

 from which the fat had been extracted 

 They not only gained in flesh but 

 also in fat, showing that fat can be pro- 

 duced from protein. The extent, however, 

 to which protein may actually be used 

 for the production of fat is not well 

 known. 



The fats contained in foods may be 

 converted into the body fat of animals. 

 This has been proved experimentally. 

 Often a very large proportion of the fats 

 fed are retained in the body. Vegetable 

 fats are quite similar to animal fats and 

 are readily converted by animals into 

 body fat. 



Fat may also be produced from car- 

 bohydrates. That is, such materials as 

 starch, sugar and crude fibre may be 



