^STRUCTURAL FORM AND EXAMINATION 287 



be large to accommodate the mammary veins and the branches 

 extending therefrom. An animal with cramped mammary 

 development and small barrel capacity cannot produce 

 economically because the machine is essentially imperfect. 

 If both the original intake and outlet of the animal are so 

 developed it is impossible to produce a normal continuous 

 flow of milk, as the one condition reacts directly against the 

 other. 



Durability and Persistency. In no class of animals, with 

 the possible exception of the horse, is durability as essential as 

 in the dairy animal. Her work is not only at a high tension 

 for a large portion of the year but in the heaviest producers 

 it is so practically during the entire year. A dairy animal 

 usually rests for about one month to six weeks from the 

 standpoint of direct milk production. However, during 

 this time she is usually nourishing a fetus which will soon 

 turn the maternal functions to milk production again and 

 thus entail the severest labor through which any animal 

 must go. The ability to withstand this pressure is a meas- 

 ure of her capacity and value as a dairy animal. The 

 brood mare works and nourishes a fetus and the colt, but 

 she is not compelled to forego the severe strain which the 

 dairy cow does during heavy milk production and through 

 gestation. The beef animal, the sheep and the hog, have the 

 strain of reproduction but they are not compelled to undergo 

 the severe and persistent work of heavy milk production 

 during this period. The dairy cow, therefore, is subjected 

 to a severer strain than any other animal, all of which involves 

 the highest development of durability and persistency. 



Structural Form and Examination. The structural form of 

 the dairy animal implies certain specific conditions which are 

 best explained by giving a detailed description of these parts. 



Head and Neck. The head of the dairy cow should be long, 

 narrow, intelligent in expression, and show every evidence of 

 femininity. The lines of the head should be clear cut and 

 generally expressive of life, vigor, and activity. 



The forehead should be broad and flat or slightly concave. 

 This is indicative of intelligence and capacity in the develop- 

 ment of nerve force. 



