86 MAINE STATE COLLEGE 



(3.) The equivalence of different classes of nutrients. 

 (4.) The relative value of animal and vegetable protein. 

 (5.) The effect of much water in the food upon assimilation. 

 Let us translate the above considerations, with others, into the 

 language of the farm. 



(1.) The most profitable mixture of foods for swine. 



(a) For growth. 



(b) For fattening. 



(2.) The relation between food and growth with swine. 



(3.) Can we substitute nitrogenous vegetable foods like pea 

 meal or gluten meal for skimmed milk, with equally good results ? 



(4.) Does a large amount of drink, as in the case of swill fed 

 pigs, for instance, diminish growth? 



(5.) The relative food value of skimmed milk and corn meal. 



(6.) The money value of skimmed milk. 



The experiments from which data are drawn for the discussion 

 of the above points have involved the use of twelve swine, six lots, 

 two animals in a lot, and were carried on at various times during 

 nearly eighteen months. In the case of four of the animals, two 

 lots, the record kept of their food and growth was continuous from 

 the young pigs to the marketed product. 



The animals were fed three times per day, and unless otherwise 

 specified, the meal or other dry material was wet v/ith the drink. 

 A small amount of bone meal was put into the food two or three 

 times each week, so that with none of the rations should there be 

 a lack of mineral compounds for bone formation. Only one case 

 of lameness occurred, and that was one of the animals of Lot 3, 

 when quite mature, and during one of the least important periods. 



It was the intention, when feeding two lots of pigs with differ- 

 ent rations for the purpose of comparing the growth obtained, to 

 give the same amount of digestible material to each lot. In order 

 to make the estimates necessary for doing this it was assumed 

 (1) that the skimmed milk contained ten per cent, of solids, all of 

 which was digestible, and (2) that equal weights of pea meal, 

 gluten meal and corn meal supplied equal weights of digestible 

 material. These assumptions would not have been admissable in 

 an investigation demanding rigid exactness, but they are consis- 

 tent with the conclusions attempted. As a matter of fact, occa- 

 sional analyses of the skimmed milk and an analysis and actual 

 determination of the digestibility of one lot of peas fed make it 

 seem reasonably certain that any errors of calculation due to these 



