author's method of feeding 149 



100. It shows that the pigs ate the most feed when they 

 were 23 weeks old, and that there was a marked reduction 

 in the amount of feed eaten after the thirty-first week. 

 The division E A represents the part of the ration used 

 for maintenance, which, according to the maintenance ex- 

 periments of the writer, is a constant quantity. 



Maintenance Requirements. — The amount of feed re- 

 quired by a pig for maintenance has never been accurate- 

 ly determined. The writer, however, by means of several 

 experiments of an empirical nature, as well as two diges- 

 tion and metabolism experiments that were quite com- 

 plete, has determined approximately how much of the 

 various food nutrients are required daily by a pig for 

 maintenance. 



It has been found that a pig requires daily as a main- 

 tenance ration per hundred pounds live weight, .1 pound 

 of digestible crude protein, .4 pound of digestible carbo- 

 hydrate, and .04 pound of digestible ether extract. It 

 has further been found that the maintenance requirement 

 is the same, when considered in per cent of live weight, 

 for pigs of different ages and different weights, as well as 

 for pigs of different breeds and of different conformation. 

 This is contrary to the idea universally held, namely, that 

 the older the pig, the more he requires for maintenance. 

 While it is true that as the pig increases in age and size 

 he requires more in absolute quantity in accordance with 

 his weight, yet the fact that the gains are more expensive 

 as the pig advances in age is not because he requires 

 more for maintenance. It is caused by an increase in the 

 factor of waste and a decrease in the amount of feed 

 eaten daily per hundred pounds live weight. 



Factor of Waste. — When a pig is fed more than a cer- 

 tain quantity of food nutrients, especially protein, he does 



