THE FATTENING OF MATURE ANIMALS 



of the experiment, a low protein ration consisting exclusively of rice 

 for 75 and 82 days, respectively. The protein content of the ration 

 and the average daily gain in live weight per head were as fol- 

 lows : 



TABLE 78. INFLUENCE OF PROTEIN SUPPLY ON GAIN BY MATURE FAT- 

 TENING SWINE 



These few results upon mature swine are of interest as showing the 

 possibility of considerable fattening on low protein rations. In prac- 

 tice the results are of comparatively little significance since the com- 

 mercial fattening of swine is usually carried out upon the immature 

 animal. 



The recorded experiments show that in the fattening of 

 mature animals as satisfactory results have been obtained with 

 rations containing 0.75 to 1.5 pounds of digestible protein per 

 1000 pounds live weight as with those containing a much more 

 abundant supply. Even these amounts, however, are from 

 50 to 100 per cent higher than is necessary for maintenance, 

 but with the exception of a small group of Kellner's experi- 

 ments in which approximately the maintenance requirement 

 of protein was consumed the results fail to show whether it is 

 practicable or advisable to reduce still further the protein con- 

 tent of fattening rations. As regards the simple question of 

 protein supply, it appears likely that an amount of this nutrient 

 but little superior to the maintenance requirement is all that is 

 absolutely necessary. In practice, however, the inferior digesti- 

 bility of low-protein rations (723, 724) as well as the fact that 

 such rations are likely to be less palatable than those furnishing 

 a more liberal supply have to be considered. The simple ad- 

 dition of non-nitrogenous nutrients to a maintenance ration 



