18i)7.] PUBLIC DOCUMENT — No. 33. Ill 



C. The Effect of Narrow and Wide Eations on the 

 Quality of the Milk. 



Many experiments have been published and many opinions 

 expressed relative to the effects of single feeds and feed com- 

 binations on the quality of milk. The writer has briefly 

 reviewed the most important of these experiments else- 

 where.* W. H. Jordan f has recently also presented a most 

 excellent review and critical examination of such experi- 

 ments. 



Practicall}^ all of the experiments thus far made have taught 

 that feeds have but very little influence on the quality of milk. 

 By " afl'ecting the quality" is meant the increasing and de- 

 creasing of any or all of the solid constituents of the milk, 

 such as casein, albumin, milk sugar, fat and ash. It is a 

 commonly recognized fact that some feeds aftect the flavor of 

 milk, and to a slight extent its color, also possibly its acidity 

 and alkalinity. It is possible that feeds and feed combina- 

 tions rich in fat have a tendency to slightly increase the per- 

 centage of fat in the milk of some cows. Whether or not 

 feeds rich in protein have a similar tendency, is still uncer- 

 tain. It is probable that this increase is only of a temporary 

 character, the milk gradually coming back to its normal con- 

 dition. Animals very thin in flesh and insufiiciently fed, if 

 brought into good condition by proper feed, will probably 

 show an increase in one or all of the solid constituents. 

 This improvement will certainly not be very marked. It is 

 possible that the improvement in the milk brought about by 

 the more complete nourishment of a thin and insufiiciently 

 fed animal consists more in an improvement in the qualUij 

 of the fat, or nitrogenous matter, than in increasing to any 

 marked degree their actual percentages in the milk. The 

 quality of milk varies, as is well known, during the diflerent 

 stages of lactation, but this is entirely independent of the 

 influence of feed. 



In conducting experiments of this character the investi- 

 gator should be very careful that he is able to control all the 

 conditions liable to in any way affect the results. The milk- 



* Twelfth report of Massachusetts Experiment Station, 1894. 

 t Agriculture of Maine, 1895, page 139. 



