374 MISSOURI AGRICULTURAL EXP. STA V RESEARCH BULLETIN NO. IO 



It is clear from a study of the subsequent data that this abnormal 

 result was due to some physiological disturbance that finally resulted 

 in the cow going entirely off feed. As soon as the carrots were re- 

 moved from the ration, the color of the fat dropped at once to 8 units 

 of yellow. However, when the animal had recovered from her attack 

 of indigestion, and the carrots were again added to the ration, the 

 effect upon the color of the milk fat was perfectly normal. On the 

 fourth day of feeding 20 Ibs.. of carrots the color had reached a max- 

 imum of 36 units of yellow. The color later dropped a little with 

 an increase in fat production which is not shown in the table, but 

 remained in the neighborhood of 28 units of yellow until the carrots 

 were removed. The color then began to drop slowly in the normal 

 way. After dropping to 7 units of yellow on the twenty-third day 

 after the carrots had been removed, the experiment was stopped. 



This experiment furnished the samples of butter fat whose pro- 

 portion of carotin and xanthophyll were studied and reported in an 

 earlier part of this paper, namely the fat after carrot feeding. 



Experiment 5. 



This was a second carrot feeding experiment using another cow, 

 i. e. Cow No. 221, a pure bred Holstein cow. The experiment was 

 not as successful as was hoped because of the peculiar appetite of the 

 cow. She refused to eat more than ten pounds of the carrots per day 

 except on two days so the experiment was discontinued. The data 

 are given in Table 15. Notwithstanding the peculiar appetite of the 

 cow it is interesting to note that the feeding of only 10 Ibs. of carrots 

 per day for 8 days was sufficient to bring the color of the milk fat 

 almost back to the starting point, i. e. 26 units of yellow. 



