TYPES AND MARKET CLASSES OF LIVE STOCK 47 



of the spinous processes of the vertebrae are soft and cartilag- 

 inous. These "buttons," as they are called, are present up to 

 the age of 18 months; thereafter they gradually ossify, and at 

 about the fifth year the spines are hard to the tips. Similar 

 changes take place in the cartilages on the breastbone before 

 the third or fourth year. The breastbone, backbone, ribs, and 

 pelvis gradually harden and whiten, especially after the age of 

 18 months. When visiting a beef cooler, the age of the animals 

 from which the carcasses came may be told approximately by 

 the bones. With increase in age the muscles become tougher 

 through use. The muscles which the animal uses most and 

 which do the most work become the toughest in their make-up; 

 these are the muscles of the neck and those used in locomotion, 

 including the muscles of the thigh, shoulder, and arm. 



Wild animals store up fat in their bodies as a reserve upon 

 which they rely in times when food is scanty. The bear, for 

 instance, takes on lots of fat during summer and fall, which is 

 resorbed and used to support life during hibernation in winter; 

 he comes out in the spring in very thin condition. The storing 

 of fat is a provision of nature. In the domestic animals which 

 produce meat, man has encouraged this fat-storing tendency 

 by methods of breeding and feeding. That great success has 

 been achieved along this line is shown by the highly finished 

 cattle, sheep, and hogs coming from the hands of the best stock- 

 men. The natural place for the storing of fat is along the back, 

 forming a layer of clear fat just beneath the skin. It is also 

 stored about the internal organs, between the muscles, and 

 within the muscles among the muscle fibers. This storing of 

 fat among the muscle fibers gives the marbled appearance already 

 referred to. Practically no fat is stored up in the muscles which 

 do much work, hence we find the round steak coming from the 

 thigh to be almost completely free from fat, being lean all the 

 way across. The muscles of the loin and back, having little 

 work to do, take on the marbling feature quite easily if the 

 animal is well bred and properly handled. This largely explains 

 why cuts from the loin and back are most tender, although in 

 these muscles there is not the stimulus to the growth of connec- 

 tive tissue such as is the case in working muscles, and this is 

 undoubtedly another reason why the loin and back yield cuts 

 of superior tenderness. 



