First and Last Milk Drawn 29 



between the morning and the evening milk. In this 

 instance the period from evening to morning was 

 about two hours longer. The amount of variation 

 that may occur between the morning and evening milk 

 is often very considerable. In the great majority 

 of cases it is not more than .5 of 1 per cent, 

 but variations so great as 2 or 2.5 per cent be- 

 tween the milk of one morning and that of the 

 preceding or following evening have frequently 

 been noticed. It is probable that a part of this 

 variation may be explained by the action of the 

 lymphatics of the udder in reabsorbing a part of 

 the fat when the milk remains for a long time 

 iu the vessels of the udder. 



There is also a considerable variation in the 

 milk from day to day. This is usually not so 

 great as between the morning and evening milking, 

 but it not infrequently amounts to 1 per cent. 

 Such daily variations may be ascribed to changes 

 in the climate or ether environment of the cows, 

 the effect of storms, the effect of change of food, 

 the effect of slight indispositions, etc.; but there 

 are numerous conditions not usually or readily 

 recognized by the owner that affect the composition 

 of the milk. It has been noted in many instances 

 that the normal effect of a slight .febrile condition 

 of the animal is to largely increase the percentage 

 of fat and albumin. If the febrile condition con- 

 tinues, and particularly if it grows more severe, 

 the fat then falls as quickly as it had risen, and 

 to a correspondingly lower point. 



