470 NUTRITION OF FARM ANIMALS 



market quality, all the feed consumed in excess of the main- 

 tenance requirement is available for the production of gain. 

 In milk production, on the contrary, what is desired is the 

 secretion of a single set of glands. An increase in weight in 

 the mature dairy cow is not sought. At best it represents a 

 diversion of feed to other purposes than the one in view, while 

 any considerable fattening tends to check the activity of the 

 milk glands. In feeding for milk production, therefore, it is 

 necessary to consider not only the surplus feed above the main- 

 tenance requirement but the factors affecting the distribution 

 of that surplus between milk production on the one hand and 

 growth or fattening on the other hand. The art of feeding for 

 milk consists in stimulating the milk production to the greatest 

 economically possible extent and in supplying the feed material 

 necessary for this production, while avoiding, in the mature 

 animal, any material increase of body tissue. 



The factors governing milk production are essentially the 

 same as in other branches of animal production, viz., the ani- 

 mal, the environment and the feed supply. 



In milk production, however, the relative importance of the 

 first and second conditions is greater than in other forms of 

 production for the reason that they may materially influence 

 the distribution of the excess feed between milk production and 

 tissue increase. 



2. THE ANIMAL AS A FACTOR IN MILK PRODUCTION 



559. The prime factor in successful dairy production is the 

 animal. Unless the latter possesses abundant secreting tissue 

 which is capable of being stimulated to a normal rate of activity 

 and of yielding a secretion of good quality, the most scrupulous 

 care and the most abundant feeding will inevitably fail to yield 

 satisfactory returns. 



Individuality 



560. Includes breed differences. The influence of in- 

 dividuality may be said to include that of breed, since a breed 

 is simply an aggregate of more or less similar and genetically 

 related individuals. It is outside the scope of this work to 

 discuss problems of breeds and breeding, and this branch of the 



