126 



SWEET POTATOES VERSUS CORNMEAL. 



The 6 Poland China pi^s employed in the first experi- 

 ment described in this bulletin were divided at the conclusion 

 of that test, into 2 lots of three each, one lot weighing 191.5 

 pounds, the other lot 189.2 pounds. 



After a week in which to accustom the pigs to their new 

 food the experiment proper, which consisted of two periods of 

 28 days each, was begun November 4. 



During the first period Lot III received a ration consist- 

 ing of three parts by weight of sweet potatoes and one part 

 ground cowpeas. During this period Lot IV was fed on a 

 ratio made up of equal weights of ground corn and ground 

 cowpeas. 



Since more than two-thirds of the weight of sweet pota- 

 toes is water, more than half of the ration of sweet potatoes and 

 cowpeas was water. The other ration contained but little 

 moisture, probably 10 or 12 per cent. 



The effort was at first made to feed equal weights of dry 

 matter to each lot. This required that each lot should con- 

 sume equal weights of peas and that for every pound of corn 

 eaten by I^ot IV three pounds of sweet potatoes should be 

 eaten by Lot III. Lot III could not be induced to eat the 

 desired quantity of sweet potatoes. Hence each lot was fed 

 all it would eat of its special ration. 



At the end of 28 days, the rations were reversed, the pigs 

 which had formerly eaten sweet potatoes and cowpeas being 

 now given coin and cowpeas, and vice versa. More than a 

 week was allowed for both lots to become accustomed to their 

 changed rations. Then the second period of the experiment, 

 consisting of 28 days was begun December 16. 



The results for both periods are plainly stated in the 

 following table : 



