172 SWINE 



profitably use, he will be able to consume a larger quan- 

 tity of nutrients. Roughages may also be used in con- 

 siderable quantities by pigs that are simply being main- 

 tained. In such a case these feeds maintain the capacity 

 of the digestive apparatus and satisfy the appetite. If 

 too much concentrated feed, and especially protein or 

 crude protein, is eaten, the factor of waste is set up which 

 makes feeding much more unprofitable and may even 

 prove fatal or result in developing permanent runts. 



METHOD OF CALCULATING RATIONS. 



According to the method of calculating rations here 

 outlined, the pig is fed certain definite quantities of di- 

 gestible nutrients daily per hundred pounds live weight, 

 aside from the fact that it is necessary to maintain a cer- 

 tain relation between the concentrates and roughages of 

 the ration. 



Method of Procedure. — As an example for calculating 

 a ration, which was also taken from manuscript that was 

 being prepared for an Illinois Agricultural Experiment 

 Station circular, the following may be taken: Suppose 

 that a bunch of pigs were to be two months old and 

 were to weigh 685 pounds, and that the curves in the' pre- 

 ceding cuts were to show that at this time the pigs re- 

 quired daily per hundred pounds live weight, 12 pounds of 

 water, .6 pound of digestible crude protein, and 2.2 pounds 

 of digestible carbohydrate. Multiplying these quantities 

 respectively by the total live weight, namely, 685 pounds, 

 and pointing off to the proper figure, we find that this 

 bunch of pigs will require a total of 82.2 pounds of water, 

 4.11 pounds of digestible crude protein, and 15.07 pounds 

 of digestible carbohydrate per day. Suppose that alfalfa, 

 corn, barley, skim milk, soy beans, and water are to be 



