96 MAINE STATE COLLEGE 



The experimental feeding of these six lots of swine included 

 nine periods, varying in length from 32 to 141 days. In six of 

 these periods the food of the lots of pigs whose growth was com- 

 pared differed greatly in the nutritive ratio, or in other words, in 

 the relation in quantity of the digestible protein to the digestible 

 carbohydrates and fats. The ration of one lot of pigs in each of 

 the six cases contained the equivalent of from 5.2 lbs. to 6.1 lbs. 

 of digestible carbohydrates for each pound of digestible protein, 

 and with these combinations the average daily gain of two pigs 

 was 2.81 lbs., the quanity of digestible food required for one pound 

 of grain being 2.90 lbs. The corresponding lots of pigs in each 

 of the six periods ate less protein and more carbohydrates, the 

 ratio being 8.9 lbs to 9.4 lbs. of digestible carbohydrates to one 

 pound of digestible protien. Here the gain of two pigs averaged 

 only 1.99 lbs. per day, 4.33 lbs. of digestible material being used 

 for each pound of grain. The pigs eating the smaller amount of 

 protein consumed about 50 per cent, more digestible food for each 

 pound of growth than did the others. 



Now these comparisons of rations were made with swine of 

 various ages and conditions, from young growing pigs to large 

 hogs that were being fattened. Consequently each period or com- 

 parison may profitably be considered separately, for while the 

 general average is largely in favor of the rations containing most 

 protein, a closer examination may show that what is true of young 

 pigs does not hold for mature animals that are being fattened. 



The feeding of the two lots of pigs, numbered 1 and 2, began 

 when the animals were about two months old. For 141 days both 

 lots ate skimmed milk and corn meal. Lot 1 eating more milk and 

 less meal than Lot 2, the digestible matter being practically the 

 same. The growth of the two lots differed but little on these 

 rations, though the nutritive ratio in one case was 1 :3.6, and in 

 the other 1 : 6.0. The milk was then taken from the ration of Lot 

 2 and continued with Lot 1, and for the next 54 days the advan- 

 tage was decidedly with Lot 1, these animals gaining 35 lbs. more 

 than the others. During the third period of 61 days the corn meal 

 ration of Lot 2 was continued, and pea meal was substituted for 

 skimmed milk in the ration of Lot 1. In this period Lot 1 gained 

 93 lbs. more than Lot 2. The feeding of the animals of Lots 5 

 and 6 also began when they were young, but the rations compared 

 differed more widely than was the case with Lots 1 and 2. For 32 



