PIGS I 317 



on the composition of the resulting increase of Hve weight. The rations 

 are indicated in Table I. 



Tablk I. — Rations tried. 



1) Corn (maize) alone. 



2) Corn and 503-3 beans) in the ratio 10.82 : i. 



3) Corn and linseed oil meal (extracted with solvents) in the ratio of 9.36 : i. 



4) Corn and wheat middlings, in the ratio 2.81 : i. 



5) Corn and slaughter-house offal, in the ratio 18.84 : i. 



6) Maize and skim milk, in the ratio 0.882 : i. 



7) Control (killed at the beginning of the experiment). 



These rations were fed so as to contain the same quantity of digestible 

 matter per unit of live weight of the pigs. The feeds supplementing the 

 corn were added in such quantities that the different rations had the same 

 ratio between protein and starch value as the non- nitrogenous substances. 

 Consequently this experiment served to a great extent for comparing the 

 growing powers of pigs when they consume equivalent quantities of protein 

 in different forms. For this purpose 35 pigs, all pure-bred Duroc- Jerseys, 

 were used, divided into 7 groups of 5. 



It was found tliat the capacity to produce increase of proteins is greater 

 for the digestible protein of milk than for the digestible protein of the vege- 

 table foods tried and slaughter-house offal. 



The maize with supplementary ration of: soya, linseed oil meal, sharps, 

 wheat middlings, slaughter-house oft'al, and skim milk, in stich propor- 

 tions that the nutritive value of the rations was i : 6.5, does not furnish 

 mineral substances corresponding to what is required for the maximum 

 growth of the bones, either as regards the nature or quantity of these sub- 

 stances. 



Rations of corn alone, and corn-|-soya, produce the mininmm in point 

 of bone growth. Rations of corn-}- slaughter-house oft'al and corn -)- skim milk 

 produce the maximum in this respect. Rations of grain alone do not pro- 

 duce a normal formation of bone. 



Among all the groups chosen for the experiuient, that which was given 

 the corn and linseed oil meal gave the maxinmm percentage of meat and 

 subcutaneous and peritoneal fat (on the whole), and the minimum percentage 

 of bone, as compared with the entire skeleton completely strippedof meat. 



The groups to which slaughter-house offal or skim milk was given had 

 the maxinmm proportions of bone as compared with the entire meatless 

 skeleton, with the cxceptionof the groups to which corn alone or corn-|-so3'a 

 was given, in which the larger proportion relatively to the skeleton was due 

 not to a greater development of the bones, but to the inferior nutrition of 

 the other tissues. 



