On the Effect of Feeding Fat to Cows. 



It is the common opinion of dairymen that the food exerts a great 

 influence upon the quality of the milk, although experiments have 

 long since shown that, in most cases, the quality of the milk is de- 

 pendent upon the individuality of the cow and is very little affected 

 by the food. The first experiments leading to these conclusions 

 were made in Germany, but several of the American Experiment 

 Stations have experimented along the same lines and in general 

 have confirmed the results of the foreign experimenters. 



These experiments, for the most part, have been made to show 

 the influence of rations relatively rich or poor in nitrogen upon the 

 quality of the milk. Comparatively few experiments have been 

 made to show the influence of rations relatively rich or poor in fat 

 upon the milk. This is no doubt due to the fact that it has long 

 been conceded that the nitrogenous part of the ration is the source 

 of a large part, if not all, of the fat in the milk. There have, how- 

 ever, been some experiments made upon feeding foods rich in fat. 

 The most important of those made in this country were made by 

 Wood of the Xew Hampshire Agricultural Experiment Station,* in 

 which cotton-seed oil, palm oil, cocoanut oil, oleo oil and stearin were 

 added to a ration composed of hay and ensilage and a grain ration 

 of eight pounds of equal parts of ground oats and middlings. The 

 oils were fed in turn to three different cows in periods of two weeks 

 each. Daily analyses of the milk were made and the conclusions 

 arrived at were as follows : 



" That the first effect of an increase of fat in the cow's ration was 

 to increase the per cent, of fat in the milk. 



" That with the continuance of such a ration, the tendency was for 

 the milk to return to its normal condition. 



"That the increase in fat is not due to the oils, but to the un- 

 natural character of the ration. 



* New Hampshire Experimental Station, Bulletin No. 20. 



