500 NUTRITION OF FARM ANIMALS 



The amounts of net energy actually available for milk pro- 

 duction correspond quite closely with the amounts computed 

 to be required according to the foregoing assumptions, and 

 Kellner states that this was also the case in a considerable 

 number of his unpublished experiments, although in others, 

 especially those in which a surplus of feed was given, the agree- 

 ment was far from being so good, the difference in one case 

 reaching 24 per cent. 



Quite in harmony with the general conclusions of the fore- 

 going paragraphs is the statement by Eckles 1 that in his ex- 

 periments " A therm of energy in the feed produced more energy 

 in milk when the per cent of fat was low than when it was high. 

 Apparently a given amount of feed is more efficient when used 

 to produce milk medium to low in fat. It appears from this 

 that the production of fat is a greater tax upon the animal than 

 is the production of other constituents of the milk carrying 

 equal energy value." 



5. FEEDING FOR MILK PRODUCTION 



595. Feeding a secondary factor. As has already been 

 urged, the feeding of a milking animal is in a certain sense a 

 secondary factor in dairying. The possibilities of successful 

 milk production depend primarily upon the capacity of the 

 animals as milk producers and upon the maintenance of such 

 an environment as will give free play to this capacity. Feed, 

 on the other hand, while equally necessary, is after all essentially 

 the supply of raw material upon which the animal mechanism 

 works and cannot greatly stimulate production, though it may 

 limit it for lack of material. 



The same thing is substantially true, of course, of all forms 

 of productive feeding, but it is especially the case in the feeding 

 of dairy animals for the reason already noted (558), that it is 

 the product of a single gland and not a general increase of body 

 tissue which is desired. Improper rations, therefore, may in 

 this case not only limit the total production but, even if suffi- 

 cient in quantity, may if deficient in quality deflect production 

 from milk to fattening, or possibly to greater muscular activity, 

 and thus fail to utilize fully the milk-producing capacity of the 



1 Loc. dt., p. 137. 



