GROWTH AND FATTENING 71 



yield less than 10 lbs. of dressed carcass, nearly half of which is water. 

 Deducting this and the bone and gristle, there remains only from 2.6 

 to 3.2 lbs. of water-free edible meat. 



The economy of gains by animals when young is evident on compar- 

 ing the figures for the calf with those for the steer, and those for the 

 lamb with those for sheep. It should also be noted that the pig ex- 

 cels all other meat-producing animals in the eflficiency with which he 

 produces human food. This is largely because he eats more feed per 

 100 lbs. live weight, and also because his food is more concentrated and 

 digestible. Both these factors increase the proportion of the food con- 

 sumed which can be used for producing gain. 



III. Studies on Grov^th and Fattening 



Feeding pigs corn only. — In 1884 Sanborn of the Missouri Agricul- 

 tural College ' carried on trials in which growing pigs fed exclusively 

 on corn meal were compared with others fed on corn meal and either 

 wheat middlings or dried blood. The corn-meal ration furnished an 

 abundance of easily digested carbohydrates and fat, but was deficient 

 in protein and mineral matter. The addition of dried blood or wheat 

 middlings to corn meal formed a ration rich in protein and mineral 

 matter as well as in carbohydrates and fat. Compared with the corn- 

 fed pigs, those getting rations rich in protein had a larger muscular 

 development and more blood, and some of their internal organs were 

 larger. 



Realizing the fundamental importance of Sanborn's studies, the 

 senior author ^ conducted numerous trials at the Wisconsin Station in 

 which dried blood, wheat middlings, field peas, and skim milk, with 

 or without corn meal, were fed in opposition to corn meal alone. 

 Similar trials were conducted at the Kansas and Alabama Stations 

 and in France. Thus at 5 widely separated points pigs were fed ra- 

 tions rich in protein and mineral matter, usually containing some 

 corn meal, in opposition to corn meal alone, which is rich in carbo- 

 hydrates and fat but low in protein and mineral matter. 



Feeding corn alone not only greatly decreased the gains of the pigs 

 but • also greatly modified the composition of their bodies. As a 

 rule, the pigs getting only corn had a smaller amount of blood and 

 smaller livers and other internal organs per 100 lbs. of carcass than 

 did those fed the rations containing ample protein and mineral mat- 

 ter. The bones of the corn-fed pigs were also abnormally weak. In 

 the first Wisconsin trial their thigh bones broke at an average pres- 

 sure of 380 lbs. for each 100 lbs. of carcass, while those fed milk, dried 



TMo. Bills. 10, 14, 19. 8 Wis. Rpts. 1886, '87, '88, '89. 



