426 MISSOURI AGRICULTURAL EXP. STA. RESEARCH BULLETIN NO. 12 



between the color readings of the butter fats than between the color 

 readings of the blood serum extracts during the second part of the 

 experiment whose data are given in Table No. 4. 



It is possible that this difference may be explained on the ground 

 that the albumin content of the milk is in some way closely related 

 to the color of the milk fat. At any rate the data given in the 

 following table admit of such interpretation. The conditions of 

 the animal preceding the data were as follows : Cow No. 301 had 

 been subjected to severe underfeeding, i. e., she received only about 

 70 per cent of the food required to produce her milk and maintain 

 her body weight. The food she received during this time was com- 

 posed of about 5 pounds of a mixture of corn, bran and linseed meal, 

 and about 7 pounds of alfalfa hay, a ration moderately rich in carotin. 

 Her ration was then changed to one practically free from carotin, 

 consisting of white corn, cottonseed meal and bleached alfalfa hay. 

 The cow was brought back to a normal plane of nutrition on this 

 ration. The immediate effect on the composition of the milk and 

 the color of the milk fat is shown in Table 5. The subsequent 

 effect upon the color of the milk fat is given in Table No. 15 of 

 the preceding Bulletin of this series which dealt with the milk fat 

 pigment. 



TABLE No. 5. A POSSIBLE RELATION BETWEEN THE ALBUMIN OF MILK AND THE 

 COLOR OF THE MILK FAT. * 

 AYRSHIRE Cow No. 301. 



(a) Alfalfa hay, rich in carotin. 



(b) Bleached alfalfa hay, free from carotin. 



(c) Calculated. 



The data in Table No. 5 shows that although the conditions of 

 feed were such that a decline in color would be expected, the reverse 

 was found. The point to be emphasized is that the sharp increase 

 in the color of the milk fat was coincident with an increase in the 



