Methods of Feeding on Forage 209 



Thrifty growthy shotes weighing 100 pounds or more will 

 ordinarily do just a little better than maintain their 

 weight when on the best of forages. Thin mature sows 

 will hold their own on good pasture and will make a gain 

 of as much as a half pound daily on alfalfa, clover, or 

 rape. Much depends, however, on their condition, 

 previous feeding, and the quality of the forage. Al- 

 though well-grown thrifty pigs may maintain their 

 weight on good forages alone for a period of several 

 months, they lose condition, take on a rough appearance, 

 and become extremely "pot-bellied" in appearance. 

 They apparently grow in bone and stature, but lose in 

 weight and fat. 



The problem of the feeder, however, is not one of main- 

 tenance but of production. He is concerned, not with 

 the cost of maintaining his pigs at a constant weight, 

 but with the cost of producing the gains which will insure 

 market finish or breeding development. An important 

 principle to remember at this point is that it is only that 

 part of the ration fed above maintenance which is avail- 

 able for growth or fat production. In the production 

 of pork, therefore, the returns from the entire ration are 

 determined by the quantity fed in excess of the main- 

 tenance requirements. Some grain is necessary if con- 

 tinuous gains are made. Just how much grain should be 

 fed while the pigs are on forage in order to insure the 

 greatest economy of production, all factors considered, 

 is the question to which we will now give our attention. 



Pigs intended for market 



In the production of market pigs, the problem of decid- 

 ing whether full or limited grain feeding, with good forages, 



