530 NUTRITION OF FARM ANIMALS 



It seems clear from the foregoing facts that the proportion of 

 fat in the milk solids, as well as the total yield of fat and its per- 

 centage in the fresh milk, may be influenced, temporarily at 

 least, by the nature of the feed, and it may be presumed that 

 some of the results obtained on this point in the earlier and less 

 conclusive experiments did, as a matter of fact, represent a real 

 effect of this sort. 



626. Significance in practice. Too much stress must not, 

 however, be laid on the physiological facts apparently estab- 

 lished by the evidence just considered. It still remains true 

 that those major differences in the composition of milk from 

 different sources which are of commercial importance are due 

 to breed and individual differences in animals (564). As has 

 been repeatedly insisted, the prime factor in successful dairy- 

 ing is the capacity of the animal as a milk producer. The 

 quality of milk best suited to meet the demands of a particular 

 market is most easily and certainly secured by intelligent 

 breeding and selection, while any influence of the feed is 

 essentially a secondary factor. At the same time the results 

 seem to indicate that while feed is a secondary factor it is 

 not altogether a negligible one. If it is possible by suitable 

 selection of feed to permanently increase the fat yield to any 

 such extent as has been observed in short experiments, or if, 

 on the other hand, it may be depressed by an unsuitable choice 

 of feeding stuffs, the matter is one of considerable importance 

 and might well be made the subject of large scale cooperative 

 investigations similar to those of the German Agricultural 

 Council on palmnut meal. 



